Merge remote-tracking branch 'oss/unstable' into module_rdb_load_errors

28 files changed, 1034 insertions, 190 deletions

diff --git a/README.md b/README.md
index 6c9435b53..3442659e6 100644
--- a/README.md
+++ b/README.md
@@ -406,7 +406,7 @@ replicas, or to continue the replication after a disconnection.
 Other C files
 ---
 
-* `t_hash.c`, `t_list.c`, `t_set.c`, `t_string.c` and `t_zset.c` contains the implementation of the Redis data types. They implement both an API to access a given data type, and the client commands implementations for these data types.
+* `t_hash.c`, `t_list.c`, `t_set.c`, `t_string.c`, `t_zset.c` and `t_stream.c` contains the implementation of the Redis data types. They implement both an API to access a given data type, and the client commands implementations for these data types.
 * `ae.c` implements the Redis event loop, it's a self contained library which is simple to read and understand.
 * `sds.c` is the Redis string library, check http://github.com/antirez/sds for more information.
 * `anet.c` is a library to use POSIX networking in a simpler way compared to the raw interface exposed by the kernel.
diff --git a/redis.conf b/redis.conf
index 74b6c018f..50ba823ac 100644
--- a/redis.conf
+++ b/redis.conf
@@ -336,13 +336,11 @@ replica-read-only yes
 
 # Replication SYNC strategy: disk or socket.
 #
-# -------------------------------------------------------
-# WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
-# -------------------------------------------------------
+# New replicas and reconnecting replicas that are not able to continue the
+# replication process just receiving differences, need to do what is called a
+# "full synchronization". An RDB file is transmitted from the master to the
+# replicas.
 #
-# New replicas and reconnecting replicas that are not able to continue the replication
-# process just receiving differences, need to do what is called a "full
-# synchronization". An RDB file is transmitted from the master to the replicas.
 # The transmission can happen in two different ways:
 #
 # 1) Disk-backed: The Redis master creates a new process that writes the RDB
@@ -352,14 +350,14 @@ replica-read-only yes
 #              RDB file to replica sockets, without touching the disk at all.
 #
 # With disk-backed replication, while the RDB file is generated, more replicas
-# can be queued and served with the RDB file as soon as the current child producing
-# the RDB file finishes its work. With diskless replication instead once
-# the transfer starts, new replicas arriving will be queued and a new transfer
-# will start when the current one terminates.
+# can be queued and served with the RDB file as soon as the current child
+# producing the RDB file finishes its work. With diskless replication instead
+# once the transfer starts, new replicas arriving will be queued and a new
+# transfer will start when the current one terminates.
 #
 # When diskless replication is used, the master waits a configurable amount of
-# time (in seconds) before starting the transfer in the hope that multiple replicas
-# will arrive and the transfer can be parallelized.
+# time (in seconds) before starting the transfer in the hope that multiple
+# replicas will arrive and the transfer can be parallelized.
 #
 # With slow disks and fast (large bandwidth) networks, diskless replication
 # works better.
@@ -370,22 +368,32 @@ repl-diskless-sync no
 # to the replicas.
 #
 # This is important since once the transfer starts, it is not possible to serve
-# new replicas arriving, that will be queued for the next RDB transfer, so the server
-# waits a delay in order to let more replicas arrive.
+# new replicas arriving, that will be queued for the next RDB transfer, so the
+# server waits a delay in order to let more replicas arrive.
 #
 # The delay is specified in seconds, and by default is 5 seconds. To disable
 # it entirely just set it to 0 seconds and the transfer will start ASAP.
 repl-diskless-sync-delay 5
 
-# Replica can load the rdb it reads from the replication link directly from the
-# socket, or store the rdb to a file and read that file after it was completely
+# -----------------------------------------------------------------------------
+# WARNING: RDB diskless load is experimental. Since in this setup the replica
+# does not immediately store an RDB on disk, it may cause data loss during
+# failovers. RDB diskless load + Redis modules not handling I/O reads may also
+# cause Redis to abort in case of I/O errors during the initial synchronization
+# stage with the master. Use only if your do what you are doing.
+# -----------------------------------------------------------------------------
+#
+# Replica can load the RDB it reads from the replication link directly from the
+# socket, or store the RDB to a file and read that file after it was completely
 # recived from the master.
+#
 # In many cases the disk is slower than the network, and storing and loading
-# the rdb file may increase replication time (and even increase the master's
+# the RDB file may increase replication time (and even increase the master's
 # Copy on Write memory and salve buffers).
-# However, parsing the rdb file directly from the socket may mean that we have
-# to flush the contents of the current database before the full rdb was received.
-# for this reason we have the following options:
+# However, parsing the RDB file directly from the socket may mean that we have
+# to flush the contents of the current database before the full rdb was
+# received. For this reason we have the following options:
+#
 # "disabled"    - Don't use diskless load (store the rdb file to the disk first)
 # "on-empty-db" - Use diskless load only when it is completely safe.
 # "swapdb"      - Keep a copy of the current db contents in RAM while parsing
@@ -393,9 +401,9 @@ repl-diskless-sync-delay 5
 #                 sufficient memory, if you don't have it, you risk an OOM kill.
 repl-diskless-load disabled
 
-# Replicas send PINGs to server in a predefined interval. It's possible to change
-# this interval with the repl_ping_replica_period option. The default value is 10
-# seconds.
+# Replicas send PINGs to server in a predefined interval. It's possible to
+# change this interval with the repl_ping_replica_period option. The default
+# value is 10 seconds.
 #
 # repl-ping-replica-period 10
 
@@ -427,10 +435,10 @@ repl-diskless-load disabled
 repl-disable-tcp-nodelay no
 
 # Set the replication backlog size. The backlog is a buffer that accumulates
-# replica data when replicas are disconnected for some time, so that when a replica
-# wants to reconnect again, often a full resync is not needed, but a partial
-# resync is enough, just passing the portion of data the replica missed while
-# disconnected.
+# replica data when replicas are disconnected for some time, so that when a
+# replica wants to reconnect again, often a full resync is not needed, but a
+# partial resync is enough, just passing the portion of data the replica
+# missed while disconnected.
 #
 # The bigger the replication backlog, the longer the time the replica can be
 # disconnected and later be able to perform a partial resynchronization.
@@ -452,13 +460,13 @@ repl-disable-tcp-nodelay no
 #
 # repl-backlog-ttl 3600
 
-# The replica priority is an integer number published by Redis in the INFO output.
-# It is used by Redis Sentinel in order to select a replica to promote into a
-# master if the master is no longer working correctly.
+# The replica priority is an integer number published by Redis in the INFO
+# output. It is used by Redis Sentinel in order to select a replica to promote
+# into a master if the master is no longer working correctly.
 #
 # A replica with a low priority number is considered better for promotion, so
-# for instance if there are three replicas with priority 10, 100, 25 Sentinel will
-# pick the one with priority 10, that is the lowest.
+# for instance if there are three replicas with priority 10, 100, 25 Sentinel
+# will pick the one with priority 10, that is the lowest.
 #
 # However a special priority of 0 marks the replica as not able to perform the
 # role of master, so a replica with priority of 0 will never be selected by
@@ -518,6 +526,39 @@ replica-priority 100
 # replica-announce-ip 5.5.5.5
 # replica-announce-port 1234
 
+############################### KEYS TRACKING #################################
+
+# Redis implements server assisted support for client side caching of values.
+# This is implemented using an invalidation table that remembers, using
+# 16 millions of slots, what clients may have certain subsets of keys. In turn
+# this is used in order to send invalidation messages to clients. Please
+# to understand more about the feature check this page:
+#
+#   https://redis.io/topics/client-side-caching
+#
+# When tracking is enabled for a client, all the read only queries are assumed
+# to be cached: this will force Redis to store information in the invalidation
+# table. When keys are modified, such information is flushed away, and
+# invalidation messages are sent to the clients. However if the workload is
+# heavily dominated by reads, Redis could use more and more memory in order
+# to track the keys fetched by many clients.
+#
+# For this reason it is possible to configure a maximum fill value for the
+# invalidation table. By default it is set to 10%, and once this limit is
+# reached, Redis will start to evict caching slots in the invalidation table
+# even if keys are not modified, just to reclaim memory: this will in turn
+# force the clients to invalidate the cached values. Basically the table
+# maximum fill rate is a trade off between the memory you want to spend server
+# side to track information about who cached what, and the ability of clients
+# to retain cached objects in memory.
+#
+# If you set the value to 0, it means there are no limits, and all the 16
+# millions of caching slots can be used at the same time. In the "stats"
+# INFO section, you can find information about the amount of caching slots
+# used at every given moment.
+#
+# tracking-table-max-fill 10
+
 ################################## SECURITY ###################################
 
 # Warning: since Redis is pretty fast an outside user can try up to
@@ -747,17 +788,17 @@ replica-priority 100
 # DEL commands to the replica as keys evict in the master side.
 #
 # This behavior ensures that masters and replicas stay consistent, and is usually
-# what you want, however if your replica is writable, or you want the replica to have
-# a different memory setting, and you are sure all the writes performed to the
-# replica are idempotent, then you may change this default (but be sure to understand
-# what you are doing).
+# what you want, however if your replica is writable, or you want the replica
+# to have a different memory setting, and you are sure all the writes performed
+# to the replica are idempotent, then you may change this default (but be sure
+# to understand what you are doing).
 #
 # Note that since the replica by default does not evict, it may end using more
 # memory than the one set via maxmemory (there are certain buffers that may
-# be larger on the replica, or data structures may sometimes take more memory and so
-# forth). So make sure you monitor your replicas and make sure they have enough
-# memory to never hit a real out-of-memory condition before the master hits
-# the configured maxmemory setting.
+# be larger on the replica, or data structures may sometimes take more memory
+# and so forth). So make sure you monitor your replicas and make sure they
+# have enough memory to never hit a real out-of-memory condition before the
+# master hits the configured maxmemory setting.
 #
 # replica-ignore-maxmemory yes
 
diff --git a/runtest-moduleapi b/runtest-moduleapi
index 84cdb9bb8..8e1c0cb23 100755
--- a/runtest-moduleapi
+++ b/runtest-moduleapi
@@ -13,4 +13,4 @@ then
 fi
 
 make -C tests/modules && \
-$TCLSH tests/test_helper.tcl --single unit/moduleapi/commandfilter "${@}"
+$TCLSH tests/test_helper.tcl --single unit/moduleapi/commandfilter --single unit/moduleapi/testrdb "${@}"
diff --git a/src/aof.c b/src/aof.c
index 565ee8073..ae9c4bb68 100644
--- a/src/aof.c
+++ b/src/aof.c
@@ -303,9 +303,7 @@ ssize_t aofWrite(int fd, const char *buf, size_t len) {
         nwritten = write(fd, buf, len);
 
         if (nwritten < 0) {
-            if (errno == EINTR) {
-                continue;
-            }
+            if (errno == EINTR) continue;
             return totwritten ? totwritten : -1;
         }
 
diff --git a/src/cluster.c b/src/cluster.c
index c85e3791d..e22222700 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -4251,12 +4251,7 @@ NULL
         }
     } else if (!strcasecmp(c->argv[1]->ptr,"nodes") && c->argc == 2) {
         /* CLUSTER NODES */
-        robj *o;
-        sds ci = clusterGenNodesDescription(0);
-
-        o = createObject(OBJ_STRING,ci);
-        addReplyBulk(c,o);
-        decrRefCount(o);
+        addReplyBulkSds(c,clusterGenNodesDescription(0));
     } else if (!strcasecmp(c->argv[1]->ptr,"myid") && c->argc == 2) {
         /* CLUSTER MYID */
         addReplyBulkCBuffer(c,myself->name, CLUSTER_NAMELEN);
@@ -4832,7 +4827,7 @@ int verifyDumpPayload(unsigned char *p, size_t len) {
  * DUMP is actually not used by Redis Cluster but it is the obvious
  * complement of RESTORE and can be useful for different applications. */
 void dumpCommand(client *c) {
-    robj *o, *dumpobj;
+    robj *o;
     rio payload;
 
     /* Check if the key is here. */
@@ -4845,9 +4840,7 @@ void dumpCommand(client *c) {
     createDumpPayload(&payload,o,c->argv[1]);
 
     /* Transfer to the client */
-    dumpobj = createObject(OBJ_STRING,payload.io.buffer.ptr);
-    addReplyBulk(c,dumpobj);
-    decrRefCount(dumpobj);
+    addReplyBulkSds(c,payload.io.buffer.ptr);
     return;
 }
 
diff --git a/src/config.c b/src/config.c
index fde00ddf5..a72df2e78 100644
--- a/src/config.c
+++ b/src/config.c
@@ -686,6 +686,17 @@ void loadServerConfigFromString(char *config) {
             }
         } else if (!strcasecmp(argv[0],"slowlog-max-len") && argc == 2) {
             server.slowlog_max_len = strtoll(argv[1],NULL,10);
+        } else if (!strcasecmp(argv[0],"tracking-table-max-fill") &&
+                   argc == 2)
+        {
+            server.tracking_table_max_fill = strtoll(argv[1],NULL,10);
+            if (server.tracking_table_max_fill > 100 ||
+                server.tracking_table_max_fill < 0)
+            {
+                err = "The tracking table fill percentage must be an "
+                      "integer between 0 and 100";
+                goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"client-output-buffer-limit") &&
                    argc == 5)
         {
@@ -1134,6 +1145,8 @@ void configSetCommand(client *c) {
       /* Cast to unsigned. */
         server.slowlog_max_len = (unsigned long)ll;
     } config_set_numerical_field(
+      "tracking-table-max-fill",server.tracking_table_max_fill,0,100) {
+    } config_set_numerical_field(
       "latency-monitor-threshold",server.latency_monitor_threshold,0,LLONG_MAX){
     } config_set_numerical_field(
       "repl-ping-slave-period",server.repl_ping_slave_period,1,INT_MAX) {
@@ -1338,8 +1351,8 @@ void configGetCommand(client *c) {
             server.slowlog_log_slower_than);
     config_get_numerical_field("latency-monitor-threshold",
             server.latency_monitor_threshold);
-    config_get_numerical_field("slowlog-max-len",
-            server.slowlog_max_len);
+    config_get_numerical_field("slowlog-max-len", server.slowlog_max_len);
+    config_get_numerical_field("tracking-table-max-fill", server.tracking_table_max_fill);
     config_get_numerical_field("port",server.port);
     config_get_numerical_field("cluster-announce-port",server.cluster_announce_port);
     config_get_numerical_field("cluster-announce-bus-port",server.cluster_announce_bus_port);
@@ -1470,12 +1483,10 @@ void configGetCommand(client *c) {
         matches++;
     }
     if (stringmatch(pattern,"notify-keyspace-events",1)) {
-        robj *flagsobj = createObject(OBJ_STRING,
-            keyspaceEventsFlagsToString(server.notify_keyspace_events));
+        sds flags = keyspaceEventsFlagsToString(server.notify_keyspace_events);
 
         addReplyBulkCString(c,"notify-keyspace-events");
-        addReplyBulk(c,flagsobj);
-        decrRefCount(flagsobj);
+        addReplyBulkSds(c,flags);
         matches++;
     }
     if (stringmatch(pattern,"bind",1)) {
@@ -2167,6 +2178,7 @@ int rewriteConfig(char *path) {
     rewriteConfigNumericalOption(state,"slowlog-log-slower-than",server.slowlog_log_slower_than,CONFIG_DEFAULT_SLOWLOG_LOG_SLOWER_THAN);
     rewriteConfigNumericalOption(state,"latency-monitor-threshold",server.latency_monitor_threshold,CONFIG_DEFAULT_LATENCY_MONITOR_THRESHOLD);
     rewriteConfigNumericalOption(state,"slowlog-max-len",server.slowlog_max_len,CONFIG_DEFAULT_SLOWLOG_MAX_LEN);
+    rewriteConfigNumericalOption(state,"tracking-table-max-fill",server.tracking_table_max_fill,CONFIG_DEFAULT_TRACKING_TABLE_MAX_FILL);
     rewriteConfigNotifykeyspaceeventsOption(state);
     rewriteConfigNumericalOption(state,"hash-max-ziplist-entries",server.hash_max_ziplist_entries,OBJ_HASH_MAX_ZIPLIST_ENTRIES);
     rewriteConfigNumericalOption(state,"hash-max-ziplist-value",server.hash_max_ziplist_value,OBJ_HASH_MAX_ZIPLIST_VALUE);
diff --git a/src/db.c b/src/db.c
index 51f5a12b4..95eaf04e9 100644
--- a/src/db.c
+++ b/src/db.c
@@ -353,6 +353,11 @@ long long emptyDbGeneric(redisDb *dbarray, int dbnum, int flags, void(callback)(
         return -1;
     }
 
+    /* Make sure the WATCHed keys are affected by the FLUSH* commands.
+     * Note that we need to call the function while the keys are still
+     * there. */
+    signalFlushedDb(dbnum);
+
     int startdb, enddb;
     if (dbnum == -1) {
         startdb = 0;
@@ -412,11 +417,12 @@ long long dbTotalServerKeyCount() {
 
 void signalModifiedKey(redisDb *db, robj *key) {
     touchWatchedKey(db,key);
-    if (server.tracking_clients) trackingInvalidateKey(key);
+    trackingInvalidateKey(key);
 }
 
 void signalFlushedDb(int dbid) {
     touchWatchedKeysOnFlush(dbid);
+    trackingInvalidateKeysOnFlush(dbid);
 }
 
 /*-----------------------------------------------------------------------------
@@ -452,7 +458,6 @@ void flushdbCommand(client *c) {
     int flags;
 
     if (getFlushCommandFlags(c,&flags) == C_ERR) return;
-    signalFlushedDb(c->db->id);
     server.dirty += emptyDb(c->db->id,flags,NULL);
     addReply(c,shared.ok);
 }
@@ -464,7 +469,6 @@ void flushallCommand(client *c) {
     int flags;
 
     if (getFlushCommandFlags(c,&flags) == C_ERR) return;
-    signalFlushedDb(-1);
     server.dirty += emptyDb(-1,flags,NULL);
     addReply(c,shared.ok);
     if (server.rdb_child_pid != -1) killRDBChild();
diff --git a/src/expire.c b/src/expire.c
index b23117a3c..598b27f96 100644
--- a/src/expire.c
+++ b/src/expire.c
@@ -64,7 +64,7 @@ int activeExpireCycleTryExpire(redisDb *db, dictEntry *de, long long now) {
             dbSyncDelete(db,keyobj);
         notifyKeyspaceEvent(NOTIFY_EXPIRED,
             "expired",keyobj,db->id);
-        if (server.tracking_clients) trackingInvalidateKey(keyobj);
+        trackingInvalidateKey(keyobj);
         decrRefCount(keyobj);
         server.stat_expiredkeys++;
         return 1;
diff --git a/src/hyperloglog.c b/src/hyperloglog.c
index e01ea6042..e0557f985 100644
--- a/src/hyperloglog.c
+++ b/src/hyperloglog.c
@@ -701,6 +701,7 @@ int hllSparseSet(robj *o, long index, uint8_t count) {
         first += span;
     }
     if (span == 0) return -1; /* Invalid format. */
+    if (span >= end) return -1; /* Invalid format. */
 
     next = HLL_SPARSE_IS_XZERO(p) ? p+2 : p+1;
     if (next >= end) next = NULL;
diff --git a/src/module.c b/src/module.c
index 36384c018..e5a1ea1ed 100644
--- a/src/module.c
+++ b/src/module.c
@@ -29,6 +29,7 @@
 
 #include "server.h"
 #include "cluster.h"
+#include "rdb.h"
 #include <dlfcn.h>
 
 #define REDISMODULE_CORE 1
@@ -3092,6 +3093,11 @@ moduleType *RM_CreateDataType(RedisModuleCtx *ctx, const char *name, int encver,
         moduleTypeMemUsageFunc mem_usage;
         moduleTypeDigestFunc digest;
         moduleTypeFreeFunc free;
+        struct {
+            moduleTypeAuxLoadFunc aux_load;
+            moduleTypeAuxSaveFunc aux_save;
+            int aux_save_triggers;
+        } v2;
     } *tms = (struct typemethods*) typemethods_ptr;
 
     moduleType *mt = zcalloc(sizeof(*mt));
@@ -3103,6 +3109,11 @@ moduleType *RM_CreateDataType(RedisModuleCtx *ctx, const char *name, int encver,
     mt->mem_usage = tms->mem_usage;
     mt->digest = tms->digest;
     mt->free = tms->free;
+    if (tms->version >= 2) {
+        mt->aux_load = tms->v2.aux_load;
+        mt->aux_save = tms->v2.aux_save;
+        mt->aux_save_triggers = tms->v2.aux_save_triggers;
+    }
     memcpy(mt->name,name,sizeof(mt->name));
     listAddNodeTail(ctx->module->types,mt);
     return mt;
@@ -3405,6 +3416,36 @@ loaderr:
     return 0;
 }
 
+/* Iterate over modules, and trigger rdb aux saving for the ones modules types
+ * who asked for it. */
+ssize_t rdbSaveModulesAux(rio *rdb, int when) {
+    size_t total_written = 0;
+    dictIterator *di = dictGetIterator(modules);
+    dictEntry *de;
+
+    while ((de = dictNext(di)) != NULL) {
+        struct RedisModule *module = dictGetVal(de);
+        listIter li;
+        listNode *ln;
+
+        listRewind(module->types,&li);
+        while((ln = listNext(&li))) {
+            moduleType *mt = ln->value;
+            if (!mt->aux_save || !(mt->aux_save_triggers & when))
+                continue;
+            ssize_t ret = rdbSaveSingleModuleAux(rdb, when, mt);
+            if (ret==-1) {
+                dictReleaseIterator(di);
+                return -1;
+            }
+            total_written += ret;
+        }
+    }
+
+    dictReleaseIterator(di);
+    return total_written;
+}
+
 /* --------------------------------------------------------------------------
  * Key digest API (DEBUG DIGEST interface for modules types)
  * -------------------------------------------------------------------------- */
@@ -3565,7 +3606,7 @@ void RM_LogRaw(RedisModule *module, const char *levelstr, const char *fmt, va_li
 
     if (level < server.verbosity) return;
 
-    name_len = snprintf(msg, sizeof(msg),"<%s> ", module->name);
+    name_len = snprintf(msg, sizeof(msg),"<%s> ", module? module->name: "module");
     vsnprintf(msg + name_len, sizeof(msg) - name_len, fmt, ap);
     serverLogRaw(level,msg);
 }
@@ -3583,13 +3624,15 @@ void RM_LogRaw(RedisModule *module, const char *levelstr, const char *fmt, va_li
  * There is a fixed limit to the length of the log line this function is able
  * to emit, this limit is not specified but is guaranteed to be more than
  * a few lines of text.
+ *
+ * The ctx argument may be NULL if cannot be provided in the context of the
+ * caller for instance threads or callbacks, in which case a generic "module"
+ * will be used instead of the module name.
  */
 void RM_Log(RedisModuleCtx *ctx, const char *levelstr, const char *fmt, ...) {
-    if (!ctx->module) return;   /* Can only log if module is initialized */
-
     va_list ap;
     va_start(ap, fmt);
-    RM_LogRaw(ctx->module,levelstr,fmt,ap);
+    RM_LogRaw(ctx? ctx->module: NULL,levelstr,fmt,ap);
     va_end(ap);
 }
 
diff --git a/src/rdb.c b/src/rdb.c
index c566378fb..4e00fad67 100644
--- a/src/rdb.c
+++ b/src/rdb.c
@@ -42,31 +42,35 @@
 #include <sys/stat.h>
 #include <sys/param.h>
 
-#define rdbExitReportCorruptRDB(...) rdbCheckThenExit(__LINE__,__VA_ARGS__)
+/* This macro is called when the internal RDB stracture is corrupt */
+#define rdbExitReportCorruptRDB(...) rdbReportError(1, __LINE__,__VA_ARGS__)
+/* This macro is called when RDB read failed (possibly a short read) */
+#define rdbReportReadError(...) rdbReportError(0, __LINE__,__VA_ARGS__)
 
 char* rdbFileBeingLoaded = NULL; /* used for rdb checking on read error */
 extern int rdbCheckMode;
 void rdbCheckError(const char *fmt, ...);
 void rdbCheckSetError(const char *fmt, ...);
 
-void rdbCheckThenExit(int linenum, char *reason, ...) {
+void rdbReportError(int corruption_error, int linenum, char *reason, ...) {
     va_list ap;
     char msg[1024];
     int len;
 
     len = snprintf(msg,sizeof(msg),
-        "Internal error in RDB reading function at rdb.c:%d -> ", linenum);
+        "Internal error in RDB reading offset %llu, function at rdb.c:%d -> ",
+        (unsigned long long)server.loading_loaded_bytes, linenum);
     va_start(ap,reason);
     vsnprintf(msg+len,sizeof(msg)-len,reason,ap);
     va_end(ap);
 
     if (!rdbCheckMode) {
-        serverLog(LL_WARNING, "%s", msg);
-        if (rdbFileBeingLoaded) {
+        if (rdbFileBeingLoaded || corruption_error) {
+            serverLog(LL_WARNING, "%s", msg);
             char *argv[2] = {"",rdbFileBeingLoaded};
             redis_check_rdb_main(2,argv,NULL);
         } else {
-            serverLog(LL_WARNING, "Failure loading rdb format from socket, assuming connection error, resuming operation.");
+            serverLog(LL_WARNING, "%s. Failure loading rdb format from socket, assuming connection error, resuming operation.", msg);
             return;
         }
     } else {
@@ -82,18 +86,6 @@ static int rdbWriteRaw(rio *rdb, void *p, size_t len) {
     return len;
 }
 
-/* This is just a wrapper for the low level function rioRead() that will
- * automatically abort if it is not possible to read the specified amount
- * of bytes. */
-void rdbLoadRaw(rio *rdb, void *buf, uint64_t len) {
-    if (rioRead(rdb,buf,len) == 0) {
-        rdbExitReportCorruptRDB(
-            "Impossible to read %llu bytes in rdbLoadRaw()",
-            (unsigned long long) len);
-        return; /* Not reached. */
-    }
-}
-
 int rdbSaveType(rio *rdb, unsigned char type) {
     return rdbWriteRaw(rdb,&type,1);
 }
@@ -109,10 +101,12 @@ int rdbLoadType(rio *rdb) {
 
 /* This is only used to load old databases stored with the RDB_OPCODE_EXPIRETIME
  * opcode. New versions of Redis store using the RDB_OPCODE_EXPIRETIME_MS
- * opcode. */
+ * opcode. On error -1 is returned, however this could be a valid time, so
+ * to check for loading errors the caller should call rioGetReadError() after
+ * calling this function. */
 time_t rdbLoadTime(rio *rdb) {
     int32_t t32;
-    rdbLoadRaw(rdb,&t32,4);
+    if (rioRead(rdb,&t32,4) == 0) return -1;
     return (time_t)t32;
 }
 
@@ -132,10 +126,14 @@ int rdbSaveMillisecondTime(rio *rdb, long long t) {
  * after upgrading to Redis version 5 they will no longer be able to load their
  * own old RDB files. Because of that, we instead fix the function only for new
  * RDB versions, and load older RDB versions as we used to do in the past,
- * allowing big endian systems to load their own old RDB files. */
+ * allowing big endian systems to load their own old RDB files.
+ *
+ * On I/O error the function returns LLONG_MAX, however if this is also a
+ * valid stored value, the caller should use rioGetReadError() to check for
+ * errors after calling this function. */
 long long rdbLoadMillisecondTime(rio *rdb, int rdbver) {
     int64_t t64;
-    rdbLoadRaw(rdb,&t64,8);
+    if (rioRead(rdb,&t64,8) == 0) return LLONG_MAX;
     if (rdbver >= 9) /* Check the top comment of this function. */
         memrev64ifbe(&t64); /* Convert in big endian if the system is BE. */
     return (long long)t64;
@@ -284,8 +282,8 @@ void *rdbLoadIntegerObject(rio *rdb, int enctype, int flags, size_t *lenptr) {
         v = enc[0]|(enc[1]<<8)|(enc[2]<<16)|(enc[3]<<24);
         val = (int32_t)v;
     } else {
-        val = 0; /* anti-warning */
         rdbExitReportCorruptRDB("Unknown RDB integer encoding type %d",enctype);
+        return NULL; /* Never reached. */
     }
     if (plain || sds) {
         char buf[LONG_STR_SIZE], *p;
@@ -388,8 +386,7 @@ void *rdbLoadLzfStringObject(rio *rdb, int flags, size_t *lenptr) {
     /* Load the compressed representation and uncompress it to target. */
     if (rioRead(rdb,c,clen) == 0) goto err;
     if (lzf_decompress(c,clen,val,len) == 0) {
-        if (rdbCheckMode) rdbCheckSetError("Invalid LZF compressed string");
-        goto err;
+        rdbExitReportCorruptRDB("Invalid LZF compressed string");
     }
     zfree(c);
 
@@ -503,6 +500,7 @@ void *rdbGenericLoadStringObject(rio *rdb, int flags, size_t *lenptr) {
             return rdbLoadLzfStringObject(rdb,flags,lenptr);
         default:
             rdbExitReportCorruptRDB("Unknown RDB string encoding type %d",len);
+            return NULL; /* Never reached. */
         }
     }
 
@@ -973,7 +971,6 @@ ssize_t rdbSaveObject(rio *rdb, robj *o, robj *key) {
         RedisModuleIO io;
         moduleValue *mv = o->ptr;
         moduleType *mt = mv->type;
-        moduleInitIOContext(io,mt,rdb,key);
 
         /* Write the "module" identifier as prefix, so that we'll be able
          * to call the right module during loading. */
@@ -982,10 +979,13 @@ ssize_t rdbSaveObject(rio *rdb, robj *o, robj *key) {
         io.bytes += retval;
 
         /* Then write the module-specific representation + EOF marker. */
+        moduleInitIOContext(io,mt,rdb,key);
         mt->rdb_save(&io,mv->value);
         retval = rdbSaveLen(rdb,RDB_MODULE_OPCODE_EOF);
-        if (retval == -1) return -1;
-        io.bytes += retval;
+        if (retval == -1)
+            io.error = 1;
+        else
+            io.bytes += retval;
 
         if (io.ctx) {
             moduleFreeContext(io.ctx);
@@ -1103,6 +1103,40 @@ int rdbSaveInfoAuxFields(rio *rdb, int flags, rdbSaveInfo *rsi) {
     return 1;
 }
 
+ssize_t rdbSaveSingleModuleAux(rio *rdb, int when, moduleType *mt) {
+    /* Save a module-specific aux value. */
+    RedisModuleIO io;
+    int retval = rdbSaveType(rdb, RDB_OPCODE_MODULE_AUX);
+
+    /* Write the "module" identifier as prefix, so that we'll be able
+     * to call the right module during loading. */
+    retval = rdbSaveLen(rdb,mt->id);
+    if (retval == -1) return -1;
+    io.bytes += retval;
+
+    /* write the 'when' so that we can provide it on loading */
+    retval = rdbSaveLen(rdb,when);
+    if (retval == -1) return -1;
+    io.bytes += retval;
+
+    /* Then write the module-specific representation + EOF marker. */
+    moduleInitIOContext(io,mt,rdb,NULL);
+    mt->aux_save(&io,when);
+    retval = rdbSaveLen(rdb,RDB_MODULE_OPCODE_EOF);
+    if (retval == -1)
+        io.error = 1;
+    else
+        io.bytes += retval;
+
+    if (io.ctx) {
+        moduleFreeContext(io.ctx);
+        zfree(io.ctx);
+    }
+    if (io.error)
+        return -1;
+    return io.bytes;
+}
+
 /* Produces a dump of the database in RDB format sending it to the specified
  * Redis I/O channel. On success C_OK is returned, otherwise C_ERR
  * is returned and part of the output, or all the output, can be
@@ -1124,6 +1158,7 @@ int rdbSaveRio(rio *rdb, int *error, int flags, rdbSaveInfo *rsi) {
     snprintf(magic,sizeof(magic),"REDIS%04d",RDB_VERSION);
     if (rdbWriteRaw(rdb,magic,9) == -1) goto werr;
     if (rdbSaveInfoAuxFields(rdb,flags,rsi) == -1) goto werr;
+    if (rdbSaveModulesAux(rdb, REDISMODULE_AUX_BEFORE_RDB) == -1) goto werr;
 
     for (j = 0; j < server.dbnum; j++) {
         redisDb *db = server.db+j;
@@ -1185,6 +1220,8 @@ int rdbSaveRio(rio *rdb, int *error, int flags, rdbSaveInfo *rsi) {
         di = NULL; /* So that we don't release it again on error. */
     }
 
+    if (rdbSaveModulesAux(rdb, REDISMODULE_AUX_AFTER_RDB) == -1) goto werr;
+
     /* EOF opcode */
     if (rdbSaveType(rdb,RDB_OPCODE_EOF) == -1) goto werr;
 
@@ -1644,6 +1681,7 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
                     hashTypeConvert(o, OBJ_ENCODING_HT);
                 break;
             default:
+                /* totally unreachable */
                 rdbExitReportCorruptRDB("Unknown RDB encoding type %d",rdbtype);
                 break;
         }
@@ -1651,6 +1689,11 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
         o = createStreamObject();
         stream *s = o->ptr;
         uint64_t listpacks = rdbLoadLen(rdb,NULL);
+        if (listpacks == RDB_LENERR) {
+            rdbReportReadError("Stream listpacks len loading failed.");
+            decrRefCount(o);
+            return NULL;
+        }
 
         while(listpacks--) {
             /* Get the master ID, the one we'll use as key of the radix tree
@@ -1658,7 +1701,9 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
              * relatively to this ID. */
             sds nodekey = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL);
             if (nodekey == NULL) {
-                rdbExitReportCorruptRDB("Stream master ID loading failed: invalid encoding or I/O error.");
+                rdbReportReadError("Stream master ID loading failed: invalid encoding or I/O error.");
+                decrRefCount(o);
+                return NULL;
             }
             if (sdslen(nodekey) != sizeof(streamID)) {
                 rdbExitReportCorruptRDB("Stream node key entry is not the "
@@ -1668,7 +1713,12 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
             /* Load the listpack. */
             unsigned char *lp =
                 rdbGenericLoadStringObject(rdb,RDB_LOAD_PLAIN,NULL);
-            if (lp == NULL) return NULL;
+            if (lp == NULL) {
+                rdbReportReadError("Stream listpacks loading failed.");
+                sdsfree(nodekey);
+                decrRefCount(o);
+                return NULL;
+            }
             unsigned char *first = lpFirst(lp);
             if (first == NULL) {
                 /* Serialized listpacks should never be empty, since on
@@ -1686,12 +1736,24 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
         }
         /* Load total number of items inside the stream. */
         s->length = rdbLoadLen(rdb,NULL);
+
         /* Load the last entry ID. */
         s->last_id.ms = rdbLoadLen(rdb,NULL);
         s->last_id.seq = rdbLoadLen(rdb,NULL);
 
+        if (rioGetReadError(rdb)) {
+            rdbReportReadError("Stream object metadata loading failed.");
+            decrRefCount(o);
+            return NULL;
+        }
+
         /* Consumer groups loading */
-        size_t cgroups_count = rdbLoadLen(rdb,NULL);
+        uint64_t cgroups_count = rdbLoadLen(rdb,NULL);
+        if (cgroups_count == RDB_LENERR) {
+            rdbReportReadError("Stream cgroup count loading failed.");
+            decrRefCount(o);
+            return NULL;
+        }
         while(cgroups_count--) {
             /* Get the consumer group name and ID. We can then create the
              * consumer group ASAP and populate its structure as
@@ -1699,11 +1761,21 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
             streamID cg_id;
             sds cgname = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL);
             if (cgname == NULL) {
-                rdbExitReportCorruptRDB(
+                rdbReportReadError(
                     "Error reading the consumer group name from Stream");
+                decrRefCount(o);
+                return NULL;
             }
+
             cg_id.ms = rdbLoadLen(rdb,NULL);
             cg_id.seq = rdbLoadLen(rdb,NULL);
+            if (rioGetReadError(rdb)) {
+                rdbReportReadError("Stream cgroup ID loading failed.");
+                sdsfree(cgname);
+                decrRefCount(o);
+                return NULL;
+            }
+
             streamCG *cgroup = streamCreateCG(s,cgname,sdslen(cgname),&cg_id);
             if (cgroup == NULL)
                 rdbExitReportCorruptRDB("Duplicated consumer group name %s",
@@ -1715,13 +1787,28 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
              * owner, since consumers for this group and their messages will
              * be read as a next step. So for now leave them not resolved
              * and later populate it. */
-            size_t pel_size = rdbLoadLen(rdb,NULL);
+            uint64_t pel_size = rdbLoadLen(rdb,NULL);
+            if (pel_size == RDB_LENERR) {
+                rdbReportReadError("Stream PEL size loading failed.");
+                decrRefCount(o);
+                return NULL;
+            }
             while(pel_size--) {
                 unsigned char rawid[sizeof(streamID)];
-                rdbLoadRaw(rdb,rawid,sizeof(rawid));
+                if (rioRead(rdb,rawid,sizeof(rawid)) == 0) {
+                    rdbReportReadError("Stream PEL ID loading failed.");
+                    decrRefCount(o);
+                    return NULL;
+                }
                 streamNACK *nack = streamCreateNACK(NULL);
                 nack->delivery_time = rdbLoadMillisecondTime(rdb,RDB_VERSION);
                 nack->delivery_count = rdbLoadLen(rdb,NULL);
+                if (rioGetReadError(rdb)) {
+                    rdbReportReadError("Stream PEL NACK loading failed.");
+                    decrRefCount(o);
+                    streamFreeNACK(nack);
+                    return NULL;
+                }
                 if (!raxInsert(cgroup->pel,rawid,sizeof(rawid),nack,NULL))
                     rdbExitReportCorruptRDB("Duplicated gobal PEL entry "
                                             "loading stream consumer group");
@@ -1729,24 +1816,47 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
 
             /* Now that we loaded our global PEL, we need to load the
              * consumers and their local PELs. */
-            size_t consumers_num = rdbLoadLen(rdb,NULL);
+            uint64_t consumers_num = rdbLoadLen(rdb,NULL);
+            if (consumers_num == RDB_LENERR) {
+                rdbReportReadError("Stream consumers num loading failed.");
+                decrRefCount(o);
+                return NULL;
+            }
             while(consumers_num--) {
                 sds cname = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL);
                 if (cname == NULL) {
-                    rdbExitReportCorruptRDB(
-                        "Error reading the consumer name from Stream group");
+                    rdbReportReadError(
+                        "Error reading the consumer name from Stream group.");
+                    decrRefCount(o);
+                    return NULL;
                 }
                 streamConsumer *consumer = streamLookupConsumer(cgroup,cname,
                                            1);
                 sdsfree(cname);
                 consumer->seen_time = rdbLoadMillisecondTime(rdb,RDB_VERSION);
+                if (rioGetReadError(rdb)) {
+                    rdbReportReadError("Stream short read reading seen time.");
+                    decrRefCount(o);
+                    return NULL;
+                }
 
                 /* Load the PEL about entries owned by this specific
                  * consumer. */
                 pel_size = rdbLoadLen(rdb,NULL);
+                if (pel_size == RDB_LENERR) {
+                    rdbReportReadError(
+                        "Stream consumer PEL num loading failed.");
+                    decrRefCount(o);
+                    return NULL;
+                }
                 while(pel_size--) {
                     unsigned char rawid[sizeof(streamID)];
-                    rdbLoadRaw(rdb,rawid,sizeof(rawid));
+                    if (rioRead(rdb,rawid,sizeof(rawid)) == 0) {
+                        rdbReportReadError(
+                            "Stream short read reading PEL streamID.");
+                        decrRefCount(o);
+                        return NULL;
+                    }
                     streamNACK *nack = raxFind(cgroup->pel,rawid,sizeof(rawid));
                     if (nack == raxNotFound)
                         rdbExitReportCorruptRDB("Consumer entry not found in "
@@ -1765,6 +1875,7 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
         }
     } else if (rdbtype == RDB_TYPE_MODULE || rdbtype == RDB_TYPE_MODULE_2) {
         uint64_t moduleid = rdbLoadLen(rdb,NULL);
+        if (rioGetReadError(rdb)) return NULL;
         moduleType *mt = moduleTypeLookupModuleByID(moduleid);
         char name[10];
 
@@ -1792,6 +1903,11 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
         /* Module v2 serialization has an EOF mark at the end. */
         if (io.ver == 2) {
             uint64_t eof = rdbLoadLen(rdb,NULL);
+            if (eof == RDB_LENERR) {
+                o = createModuleObject(mt,ptr); /* creating just in order to easily destroy */
+                decrRefCount(o);
+                return NULL;
+            }
             if (eof != RDB_MODULE_OPCODE_EOF) {
                 serverLog(LL_WARNING,"The RDB file contains module data for the module '%s' that is not terminated by the proper module value EOF marker", name);
                 exit(1);
@@ -1805,7 +1921,8 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
         }
         o = createModuleObject(mt,ptr);
     } else {
-        rdbExitReportCorruptRDB("Unknown RDB encoding type %d",rdbtype);
+        rdbReportReadError("Unknown RDB encoding type %d",rdbtype);
+        return NULL;
     }
     return o;
 }
@@ -1904,11 +2021,13 @@ int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi, int loading_aof) {
              * load the actual type, and continue. */
             expiretime = rdbLoadTime(rdb);
             expiretime *= 1000;
+            if (rioGetReadError(rdb)) goto eoferr;
             continue; /* Read next opcode. */
         } else if (type == RDB_OPCODE_EXPIRETIME_MS) {
             /* EXPIRETIME_MS: milliseconds precision expire times introduced
              * with RDB v3. Like EXPIRETIME but no with more precision. */
             expiretime = rdbLoadMillisecondTime(rdb,rdbver);
+            if (rioGetReadError(rdb)) goto eoferr;
             continue; /* Read next opcode. */
         } else if (type == RDB_OPCODE_FREQ) {
             /* FREQ: LFU frequency. */
@@ -2009,15 +2128,12 @@ int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi, int loading_aof) {
             decrRefCount(auxval);
             continue; /* Read type again. */
         } else if (type == RDB_OPCODE_MODULE_AUX) {
-            /* This is just for compatibility with the future: we have plans
-             * to add the ability for modules to store anything in the RDB
-             * file, like data that is not related to the Redis key space.
-             * Such data will potentially be stored both before and after the
-             * RDB keys-values section. For this reason since RDB version 9,
-             * we have the ability to read a MODULE_AUX opcode followed by an
-             * identifier of the module, and a serialized value in "MODULE V2"
-             * format. */
+            /* Load module data that is not related to the Redis key space.
+             * Such data can be potentially be stored both before and after the
+             * RDB keys-values section. */
             uint64_t moduleid = rdbLoadLen(rdb,NULL);
+            int when = rdbLoadLen(rdb,NULL);
+            if (rioGetReadError(rdb)) goto eoferr;
             moduleType *mt = moduleTypeLookupModuleByID(moduleid);
             char name[10];
             moduleTypeNameByID(name,moduleid);
@@ -2027,14 +2143,37 @@ int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi, int loading_aof) {
                 serverLog(LL_WARNING,"The RDB file contains AUX module data I can't load: no matching module '%s'", name);
                 exit(1);
             } else if (!rdbCheckMode && mt != NULL) {
-                /* This version of Redis actually does not know what to do
-                 * with modules AUX data... */
-                serverLog(LL_WARNING,"The RDB file contains AUX module data I can't load for the module '%s'. Probably you want to use a newer version of Redis which implements aux data callbacks", name);
-                exit(1);
+                if (!mt->aux_load) {
+                    /* Module doesn't support AUX. */
+                    serverLog(LL_WARNING,"The RDB file contains module AUX data, but the module '%s' doesn't seem to support it.", name);
+                    exit(1);
+                }
+
+                RedisModuleIO io;
+                moduleInitIOContext(io,mt,rdb,NULL);
+                io.ver = 2;
+                /* Call the rdb_load method of the module providing the 10 bit
+                 * encoding version in the lower 10 bits of the module ID. */
+                if (mt->aux_load(&io,moduleid&1023, when) || io.error) {
+                    moduleTypeNameByID(name,moduleid);
+                    serverLog(LL_WARNING,"The RDB file contains module AUX data for the module type '%s', that the responsible module is not able to load. Check for modules log above for additional clues.", name);
+                    exit(1);
+                }
+                if (io.ctx) {
+                    moduleFreeContext(io.ctx);
+                    zfree(io.ctx);
+                }
+                uint64_t eof = rdbLoadLen(rdb,NULL);
+                if (eof != RDB_MODULE_OPCODE_EOF) {
+                    serverLog(LL_WARNING,"The RDB file contains module AUX data for the module '%s' that is not terminated by the proper module value EOF marker", name);
+                    exit(1);
+                }
+                continue;
             } else {
                 /* RDB check mode. */
                 robj *aux = rdbLoadCheckModuleValue(rdb,name);
                 decrRefCount(aux);
+                continue; /* Read next opcode. */
             }
         }
 
@@ -2088,10 +2227,15 @@ int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi, int loading_aof) {
     }
     return C_OK;
 
-eoferr: /* unexpected end of file is handled here with a fatal exit */
-    serverLog(LL_WARNING,"Short read or OOM loading DB. Unrecoverable error, aborting now.");
-    rdbExitReportCorruptRDB("Unexpected EOF reading RDB file");
-    return C_ERR; /* Just to avoid warning */
+    /* Unexpected end of file is handled here calling rdbReportReadError():
+     * this will in turn either abort Redis in most cases, or if we are loading
+     * the RDB file from a socket during initial SYNC (diskless replica mode),
+     * we'll report the error to the caller, so that we can retry. */
+eoferr:
+    serverLog(LL_WARNING,
+        "Short read or OOM loading DB. Unrecoverable error, aborting now.");
+    rdbReportReadError("Unexpected EOF reading RDB file");
+    return C_ERR;
 }
 
 /* Like rdbLoadRio() but takes a filename instead of a rio stream. The
diff --git a/src/rdb.h b/src/rdb.h
index 0acddf9ab..40a50f7ba 100644
--- a/src/rdb.h
+++ b/src/rdb.h
@@ -145,6 +145,7 @@ size_t rdbSavedObjectLen(robj *o);
 robj *rdbLoadObject(int type, rio *rdb, robj *key);
 void backgroundSaveDoneHandler(int exitcode, int bysignal);
 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime);
+ssize_t rdbSaveSingleModuleAux(rio *rdb, int when, moduleType *mt);
 robj *rdbLoadStringObject(rio *rdb);
 ssize_t rdbSaveStringObject(rio *rdb, robj *obj);
 ssize_t rdbSaveRawString(rio *rdb, unsigned char *s, size_t len);
diff --git a/src/redis-benchmark.c b/src/redis-benchmark.c
index 1d16fa4ee..2df41580b 100644
--- a/src/redis-benchmark.c
+++ b/src/redis-benchmark.c
@@ -104,6 +104,7 @@ static struct config {
     int is_fetching_slots;
     int is_updating_slots;
     int slots_last_update;
+    int enable_tracking;
     /* Thread mutexes to be used as fallbacks by atomicvar.h */
     pthread_mutex_t requests_issued_mutex;
     pthread_mutex_t requests_finished_mutex;
@@ -255,7 +256,7 @@ static redisConfig *getRedisConfig(const char *ip, int port,
         goto fail;
     }
 
-    if(config.auth){
+    if(config.auth) {
         void *authReply = NULL;
         redisAppendCommand(c, "AUTH %s", config.auth);
         if (REDIS_OK != redisGetReply(c, &authReply)) goto fail;
@@ -633,6 +634,14 @@ static client createClient(char *cmd, size_t len, client from, int thread_id) {
         c->prefix_pending++;
     }
 
+    if (config.enable_tracking) {
+        char *buf = NULL;
+        int len = redisFormatCommand(&buf, "CLIENT TRACKING on");
+        c->obuf = sdscatlen(c->obuf, buf, len);
+        free(buf);
+        c->prefix_pending++;
+    }
+
     /* If a DB number different than zero is selected, prefix our request
      * buffer with the SELECT command, that will be discarded the first
      * time the replies are received, so if the client is reused the
@@ -1350,6 +1359,8 @@ int parseOptions(int argc, const char **argv) {
              } else if (config.num_threads < 0) config.num_threads = 0;
         } else if (!strcmp(argv[i],"--cluster")) {
             config.cluster_mode = 1;
+        } else if (!strcmp(argv[i],"--enable-tracking")) {
+            config.enable_tracking = 1;
         } else if (!strcmp(argv[i],"--help")) {
             exit_status = 0;
             goto usage;
@@ -1380,6 +1391,7 @@ usage:
 " --dbnum <db>       SELECT the specified db number (default 0)\n"
 " --threads <num>    Enable multi-thread mode.\n"
 " --cluster          Enable cluster mode.\n"
+" --enable-tracking  Send CLIENT TRACKING on before starting benchmark.\n"
 " -k <boolean>       1=keep alive 0=reconnect (default 1)\n"
 " -r <keyspacelen>   Use random keys for SET/GET/INCR, random values for SADD\n"
 "  Using this option the benchmark will expand the string __rand_int__\n"
@@ -1504,6 +1516,7 @@ int main(int argc, const char **argv) {
     config.is_fetching_slots = 0;
     config.is_updating_slots = 0;
     config.slots_last_update = 0;
+    config.enable_tracking = 0;
 
     i = parseOptions(argc,argv);
     argc -= i;
diff --git a/src/redis-check-rdb.c b/src/redis-check-rdb.c
index e2d71b5a5..5e7415046 100644
--- a/src/redis-check-rdb.c
+++ b/src/redis-check-rdb.c
@@ -216,14 +216,16 @@ int redis_check_rdb(char *rdbfilename, FILE *fp) {
             /* EXPIRETIME: load an expire associated with the next key
              * to load. Note that after loading an expire we need to
              * load the actual type, and continue. */
-            if ((expiretime = rdbLoadTime(&rdb)) == -1) goto eoferr;
+            expiretime = rdbLoadTime(&rdb);
             expiretime *= 1000;
+            if (rioGetReadError(&rdb)) goto eoferr;
             continue; /* Read next opcode. */
         } else if (type == RDB_OPCODE_EXPIRETIME_MS) {
             /* EXPIRETIME_MS: milliseconds precision expire times introduced
              * with RDB v3. Like EXPIRETIME but no with more precision. */
             rdbstate.doing = RDB_CHECK_DOING_READ_EXPIRE;
-            if ((expiretime = rdbLoadMillisecondTime(&rdb, rdbver)) == -1) goto eoferr;
+            expiretime = rdbLoadMillisecondTime(&rdb, rdbver);
+            if (rioGetReadError(&rdb)) goto eoferr;
             continue; /* Read next opcode. */
         } else if (type == RDB_OPCODE_FREQ) {
             /* FREQ: LFU frequency. */
diff --git a/src/redismodule.h b/src/redismodule.h
index f0f27c067..e08aa16d4 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -129,6 +129,10 @@
 
 #define REDISMODULE_NOT_USED(V) ((void) V)
 
+/* Bit flags for aux_save_triggers and the aux_load and aux_save callbacks */
+#define REDISMODULE_AUX_BEFORE_RDB (1<<0)
+#define REDISMODULE_AUX_AFTER_RDB (1<<1)
+
 /* This type represents a timer handle, and is returned when a timer is
  * registered and used in order to invalidate a timer. It's just a 64 bit
  * number, because this is how each timer is represented inside the radix tree
@@ -169,6 +173,8 @@ typedef void (*RedisModuleDisconnectFunc)(RedisModuleCtx *ctx, RedisModuleBlocke
 typedef int (*RedisModuleNotificationFunc)(RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key);
 typedef void *(*RedisModuleTypeLoadFunc)(RedisModuleIO *rdb, int encver);
 typedef void (*RedisModuleTypeSaveFunc)(RedisModuleIO *rdb, void *value);
+typedef int (*RedisModuleTypeAuxLoadFunc)(RedisModuleIO *rdb, int encver, int when);
+typedef void (*RedisModuleTypeAuxSaveFunc)(RedisModuleIO *rdb, int when);
 typedef void (*RedisModuleTypeRewriteFunc)(RedisModuleIO *aof, RedisModuleString *key, void *value);
 typedef size_t (*RedisModuleTypeMemUsageFunc)(const void *value);
 typedef void (*RedisModuleTypeDigestFunc)(RedisModuleDigest *digest, void *value);
@@ -177,7 +183,7 @@ typedef void (*RedisModuleClusterMessageReceiver)(RedisModuleCtx *ctx, const cha
 typedef void (*RedisModuleTimerProc)(RedisModuleCtx *ctx, void *data);
 typedef void (*RedisModuleCommandFilterFunc) (RedisModuleCommandFilterCtx *filter);
 
-#define REDISMODULE_TYPE_METHOD_VERSION 1
+#define REDISMODULE_TYPE_METHOD_VERSION 2
 typedef struct RedisModuleTypeMethods {
     uint64_t version;
     RedisModuleTypeLoadFunc rdb_load;
@@ -186,6 +192,9 @@ typedef struct RedisModuleTypeMethods {
     RedisModuleTypeMemUsageFunc mem_usage;
     RedisModuleTypeDigestFunc digest;
     RedisModuleTypeFreeFunc free;
+    RedisModuleTypeAuxLoadFunc aux_load;
+    RedisModuleTypeAuxSaveFunc aux_save;
+    int aux_save_triggers;
 } RedisModuleTypeMethods;
 
 #define REDISMODULE_GET_API(name) \
diff --git a/src/rio.c b/src/rio.c
index 5359bc3d6..bdbc5d0e9 100644
--- a/src/rio.c
+++ b/src/rio.c
@@ -92,6 +92,7 @@ static const rio rioBufferIO = {
     rioBufferFlush,
     NULL,           /* update_checksum */
     0,              /* current checksum */
+    0,              /* flags */
     0,              /* bytes read or written */
     0,              /* read/write chunk size */
     { { NULL, 0 } } /* union for io-specific vars */
@@ -145,6 +146,7 @@ static const rio rioFileIO = {
     rioFileFlush,
     NULL,           /* update_checksum */
     0,              /* current checksum */
+    0,              /* flags */
     0,              /* bytes read or written */
     0,              /* read/write chunk size */
     { { NULL, 0 } } /* union for io-specific vars */
@@ -239,6 +241,7 @@ static const rio rioFdIO = {
     rioFdFlush,
     NULL,           /* update_checksum */
     0,              /* current checksum */
+    0,              /* flags */
     0,              /* bytes read or written */
     0,              /* read/write chunk size */
     { { NULL, 0 } } /* union for io-specific vars */
@@ -374,6 +377,7 @@ static const rio rioFdsetIO = {
     rioFdsetFlush,
     NULL,           /* update_checksum */
     0,              /* current checksum */
+    0,              /* flags */
     0,              /* bytes read or written */
     0,              /* read/write chunk size */
     { { NULL, 0 } } /* union for io-specific vars */
diff --git a/src/rio.h b/src/rio.h
index beea06888..6199bb039 100644
--- a/src/rio.h
+++ b/src/rio.h
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2009-2012, Pieter Noordhuis <pcnoordhuis at gmail dot com>
- * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2009-2019, Salvatore Sanfilippo <antirez at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,6 +36,9 @@
 #include <stdint.h>
 #include "sds.h"
 
+#define RIO_FLAG_READ_ERROR (1<<0)
+#define RIO_FLAG_WRITE_ERROR (1<<1)
+
 struct _rio {
     /* Backend functions.
      * Since this functions do not tolerate short writes or reads the return
@@ -51,8 +54,8 @@ struct _rio {
      * computation. */
     void (*update_cksum)(struct _rio *, const void *buf, size_t len);
 
-    /* The current checksum */
-    uint64_t cksum;
+    /* The current checksum and flags (see RIO_FLAG_*) */
+    uint64_t cksum, flags;
 
     /* number of bytes read or written */
     size_t processed_bytes;
@@ -99,11 +102,14 @@ typedef struct _rio rio;
  * if needed. */
 
 static inline size_t rioWrite(rio *r, const void *buf, size_t len) {
+    if (r->flags & RIO_FLAG_WRITE_ERROR) return 0;
     while (len) {
         size_t bytes_to_write = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len;
         if (r->update_cksum) r->update_cksum(r,buf,bytes_to_write);
-        if (r->write(r,buf,bytes_to_write) == 0)
+        if (r->write(r,buf,bytes_to_write) == 0) {
+            r->flags |= RIO_FLAG_WRITE_ERROR;
             return 0;
+        }
         buf = (char*)buf + bytes_to_write;
         len -= bytes_to_write;
         r->processed_bytes += bytes_to_write;
@@ -112,10 +118,13 @@ static inline size_t rioWrite(rio *r, const void *buf, size_t len) {
 }
 
 static inline size_t rioRead(rio *r, void *buf, size_t len) {
+    if (r->flags & RIO_FLAG_READ_ERROR) return 0;
     while (len) {
         size_t bytes_to_read = (r->max_processing_chunk && r->max_processing_chunk < len) ? r->max_processing_chunk : len;
-        if (r->read(r,buf,bytes_to_read) == 0)
+        if (r->read(r,buf,bytes_to_read) == 0) {
+            r->flags |= RIO_FLAG_READ_ERROR;
             return 0;
+        }
         if (r->update_cksum) r->update_cksum(r,buf,bytes_to_read);
         buf = (char*)buf + bytes_to_read;
         len -= bytes_to_read;
@@ -132,6 +141,22 @@ static inline int rioFlush(rio *r) {
     return r->flush(r);
 }
 
+/* This function allows to know if there was a read error in any past
+ * operation, since the rio stream was created or since the last call
+ * to rioClearError(). */
+static inline int rioGetReadError(rio *r) {
+    return (r->flags & RIO_FLAG_READ_ERROR) != 0;
+}
+
+/* Like rioGetReadError() but for write errors. */
+static inline int rioGetWriteError(rio *r) {
+    return (r->flags & RIO_FLAG_READ_ERROR) != 0;
+}
+
+static inline void rioClearErrors(rio *r) {
+    r->flags &= ~(RIO_FLAG_READ_ERROR|RIO_FLAG_WRITE_ERROR);
+}
+
 void rioInitWithFile(rio *r, FILE *fp);
 void rioInitWithBuffer(rio *r, sds s);
 void rioInitWithFd(rio *r, int fd, size_t read_limit);
diff --git a/src/server.c b/src/server.c
index 4337b8f01..eb5cef386 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2403,6 +2403,9 @@ void initServerConfig(void) {
     /* Latency monitor */
     server.latency_monitor_threshold = CONFIG_DEFAULT_LATENCY_MONITOR_THRESHOLD;
 
+    /* Tracking. */
+    server.tracking_table_max_fill = CONFIG_DEFAULT_TRACKING_TABLE_MAX_FILL;
+
     /* Debugging */
     server.assert_failed = "<no assertion failed>";
     server.assert_file = "<no file>";
@@ -3401,6 +3404,10 @@ int processCommand(client *c) {
         }
     }
 
+    /* Make sure to use a reasonable amount of memory for client side
+     * caching metadata. */
+    if (server.tracking_clients) trackingLimitUsedSlots();
+
     /* Don't accept write commands if there are problems persisting on disk
      * and if this is a master instance. */
     int deny_write_type = writeCommandsDeniedByDiskError();
@@ -4140,7 +4147,8 @@ sds genRedisInfoString(char *section) {
             "active_defrag_hits:%lld\r\n"
             "active_defrag_misses:%lld\r\n"
             "active_defrag_key_hits:%lld\r\n"
-            "active_defrag_key_misses:%lld\r\n",
+            "active_defrag_key_misses:%lld\r\n"
+            "tracking_used_slots:%lld\r\n",
             server.stat_numconnections,
             server.stat_numcommands,
             getInstantaneousMetric(STATS_METRIC_COMMAND),
@@ -4166,7 +4174,8 @@ sds genRedisInfoString(char *section) {
             server.stat_active_defrag_hits,
             server.stat_active_defrag_misses,
             server.stat_active_defrag_key_hits,
-            server.stat_active_defrag_key_misses);
+            server.stat_active_defrag_key_misses,
+            trackingGetUsedSlots());
     }
 
     /* Replication */
diff --git a/src/server.h b/src/server.h
index 5991cfa6c..a7f38a7a9 100644
--- a/src/server.h
+++ b/src/server.h
@@ -171,6 +171,7 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CONFIG_DEFAULT_DEFRAG_CYCLE_MAX 75 /* 75% CPU max (at upper threshold) */
 #define CONFIG_DEFAULT_DEFRAG_MAX_SCAN_FIELDS 1000 /* keys with more than 1000 fields will be processed separately */
 #define CONFIG_DEFAULT_PROTO_MAX_BULK_LEN (512ll*1024*1024) /* Bulk request max size */
+#define CONFIG_DEFAULT_TRACKING_TABLE_MAX_FILL 10 /* 10% tracking table max fill. */
 
 #define ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP 20 /* Loopkups per loop. */
 #define ACTIVE_EXPIRE_CYCLE_FAST_DURATION 1000 /* Microseconds */
@@ -536,6 +537,10 @@ typedef long long mstime_t; /* millisecond time type. */
 #define REDISMODULE_TYPE_ENCVER(id) (id & REDISMODULE_TYPE_ENCVER_MASK)
 #define REDISMODULE_TYPE_SIGN(id) ((id & ~((uint64_t)REDISMODULE_TYPE_ENCVER_MASK)) >>REDISMODULE_TYPE_ENCVER_BITS)
 
+/* Bit flags for moduleTypeAuxSaveFunc */
+#define REDISMODULE_AUX_BEFORE_RDB (1<<0)
+#define REDISMODULE_AUX_AFTER_RDB (1<<1)
+
 struct RedisModule;
 struct RedisModuleIO;
 struct RedisModuleDigest;
@@ -548,6 +553,8 @@ struct redisObject;
  * is deleted. */
 typedef void *(*moduleTypeLoadFunc)(struct RedisModuleIO *io, int encver);
 typedef void (*moduleTypeSaveFunc)(struct RedisModuleIO *io, void *value);
+typedef int (*moduleTypeAuxLoadFunc)(struct RedisModuleIO *rdb, int encver, int when);
+typedef void (*moduleTypeAuxSaveFunc)(struct RedisModuleIO *rdb, int when);
 typedef void (*moduleTypeRewriteFunc)(struct RedisModuleIO *io, struct redisObject *key, void *value);
 typedef void (*moduleTypeDigestFunc)(struct RedisModuleDigest *digest, void *value);
 typedef size_t (*moduleTypeMemUsageFunc)(const void *value);
@@ -564,6 +571,9 @@ typedef struct RedisModuleType {
     moduleTypeMemUsageFunc mem_usage;
     moduleTypeDigestFunc digest;
     moduleTypeFreeFunc free;
+    moduleTypeAuxLoadFunc aux_load;
+    moduleTypeAuxSaveFunc aux_save;
+    int aux_save_triggers;
     char name[10]; /* 9 bytes name + null term. Charset: A-Z a-z 0-9 _- */
 } moduleType;
 
@@ -1316,6 +1326,7 @@ struct redisServer {
     list *ready_keys;        /* List of readyList structures for BLPOP & co */
     /* Client side caching. */
     unsigned int tracking_clients;  /* # of clients with tracking enabled.*/
+    int tracking_table_max_fill;    /* Max fill percentage. */
     /* Sort parameters - qsort_r() is only available under BSD so we
      * have to take this state global, in order to pass it to sortCompare() */
     int sort_desc;
@@ -1528,6 +1539,7 @@ void moduleAcquireGIL(void);
 void moduleReleaseGIL(void);
 void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid);
 void moduleCallCommandFilters(client *c);
+ssize_t rdbSaveModulesAux(rio *rdb, int when);
 int moduleAllDatatypesHandleErrors();
 
 /* Utils */
@@ -1639,6 +1651,9 @@ void enableTracking(client *c, uint64_t redirect_to);
 void disableTracking(client *c);
 void trackingRememberKeys(client *c);
 void trackingInvalidateKey(robj *keyobj);
+void trackingInvalidateKeysOnFlush(int dbid);
+void trackingLimitUsedSlots(void);
+unsigned long long trackingGetUsedSlots(void);
 
 /* List data type */
 void listTypeTryConversion(robj *subject, robj *value);
diff --git a/src/stream.h b/src/stream.h
index ef08753b5..8ae90ce77 100644
--- a/src/stream.h
+++ b/src/stream.h
@@ -109,5 +109,6 @@ streamCG *streamCreateCG(stream *s, char *name, size_t namelen, streamID *id);
 streamNACK *streamCreateNACK(streamConsumer *consumer);
 void streamDecodeID(void *buf, streamID *id);
 int streamCompareID(streamID *a, streamID *b);
+void streamFreeNACK(streamNACK *na);
 
 #endif
diff --git a/src/t_zset.c b/src/t_zset.c
index fb7078abd..2680e76a9 100644
--- a/src/t_zset.c
+++ b/src/t_zset.c
@@ -1357,9 +1357,8 @@ int zsetAdd(robj *zobj, double score, sds ele, int *flags, double *newscore) {
             /* Optimize: check if the element is too large or the list
              * becomes too long *before* executing zzlInsert. */
             zobj->ptr = zzlInsert(zobj->ptr,ele,score);
-            if (zzlLength(zobj->ptr) > server.zset_max_ziplist_entries)
-                zsetConvert(zobj,OBJ_ENCODING_SKIPLIST);
-            if (sdslen(ele) > server.zset_max_ziplist_value)
+            if (zzlLength(zobj->ptr) > server.zset_max_ziplist_entries ||
+                sdslen(ele) > server.zset_max_ziplist_value)
                 zsetConvert(zobj,OBJ_ENCODING_SKIPLIST);
             if (newscore) *newscore = score;
             *flags |= ZADD_ADDED;
diff --git a/src/tracking.c b/src/tracking.c
index bbfc66a72..f7f0fc755 100644
--- a/src/tracking.c
+++ b/src/tracking.c
@@ -60,6 +60,7 @@
  * use the most significant bits instead of the full 24 bits. */
 #define TRACKING_TABLE_SIZE (1<<24)
 rax **TrackingTable = NULL;
+unsigned long TrackingTableUsedSlots = 0;
 robj *TrackingChannelName;
 
 /* Remove the tracking state from the client 'c'. Note that there is not much
@@ -109,67 +110,187 @@ void trackingRememberKeys(client *c) {
         sds sdskey = c->argv[idx]->ptr;
         uint64_t hash = crc64(0,
             (unsigned char*)sdskey,sdslen(sdskey))&(TRACKING_TABLE_SIZE-1);
-        if (TrackingTable[hash] == NULL)
+        if (TrackingTable[hash] == NULL) {
             TrackingTable[hash] = raxNew();
+            TrackingTableUsedSlots++;
+        }
         raxTryInsert(TrackingTable[hash],
             (unsigned char*)&c->id,sizeof(c->id),NULL,NULL);
     }
     getKeysFreeResult(keys);
 }
 
-/* This function is called from signalModifiedKey() or other places in Redis
- * when a key changes value. In the context of keys tracking, our task here is
- * to send a notification to every client that may have keys about such . */
-void trackingInvalidateKey(robj *keyobj) {
-    sds sdskey = keyobj->ptr;
-    uint64_t hash = crc64(0,
-        (unsigned char*)sdskey,sdslen(sdskey))&(TRACKING_TABLE_SIZE-1);
-    if (TrackingTable == NULL || TrackingTable[hash] == NULL) return;
+void sendTrackingMessage(client *c, long long hash) {
+    int using_redirection = 0;
+    if (c->client_tracking_redirection) {
+        client *redir = lookupClientByID(c->client_tracking_redirection);
+        if (!redir) {
+            /* We need to signal to the original connection that we
+             * are unable to send invalidation messages to the redirected
+             * connection, because the client no longer exist. */
+            if (c->resp > 2) {
+                addReplyPushLen(c,3);
+                addReplyBulkCBuffer(c,"tracking-redir-broken",21);
+                addReplyLongLong(c,c->client_tracking_redirection);
+            }
+            return;
+        }
+        c = redir;
+        using_redirection = 1;
+    }
+
+    /* Only send such info for clients in RESP version 3 or more. However
+     * if redirection is active, and the connection we redirect to is
+     * in Pub/Sub mode, we can support the feature with RESP 2 as well,
+     * by sending Pub/Sub messages in the __redis__:invalidate channel. */
+    if (c->resp > 2) {
+        addReplyPushLen(c,2);
+        addReplyBulkCBuffer(c,"invalidate",10);
+        addReplyLongLong(c,hash);
+    } else if (using_redirection && c->flags & CLIENT_PUBSUB) {
+        robj *msg = createStringObjectFromLongLong(hash);
+        addReplyPubsubMessage(c,TrackingChannelName,msg);
+        decrRefCount(msg);
+    }
+}
+
+/* Invalidates a caching slot: this is actually the low level implementation
+ * of the API that Redis calls externally, that is trackingInvalidateKey(). */
+void trackingInvalidateSlot(uint64_t slot) {
+    if (TrackingTable == NULL || TrackingTable[slot] == NULL) return;
 
     raxIterator ri;
-    raxStart(&ri,TrackingTable[hash]);
+    raxStart(&ri,TrackingTable[slot]);
     raxSeek(&ri,"^",NULL,0);
     while(raxNext(&ri)) {
         uint64_t id;
         memcpy(&id,ri.key,ri.key_len);
         client *c = lookupClientByID(id);
-        if (c == NULL) continue;
-        int using_redirection = 0;
-        if (c->client_tracking_redirection) {
-            client *redir = lookupClientByID(c->client_tracking_redirection);
-            if (!redir) {
-                /* We need to signal to the original connection that we
-                 * are unable to send invalidation messages to the redirected
-                 * connection, because the client no longer exist. */
-                if (c->resp > 2) {
-                    addReplyPushLen(c,3);
-                    addReplyBulkCBuffer(c,"tracking-redir-broken",21);
-                    addReplyLongLong(c,c->client_tracking_redirection);
-                }
-                continue;
+        if (c == NULL || !(c->flags & CLIENT_TRACKING)) continue;
+        sendTrackingMessage(c,slot);
+    }
+    raxStop(&ri);
+
+    /* Free the tracking table: we'll create the radix tree and populate it
+     * again if more keys will be modified in this caching slot. */
+    raxFree(TrackingTable[slot]);
+    TrackingTable[slot] = NULL;
+    TrackingTableUsedSlots--;
+}
+
+/* This function is called from signalModifiedKey() or other places in Redis
+ * when a key changes value. In the context of keys tracking, our task here is
+ * to send a notification to every client that may have keys about such caching
+ * slot. */
+void trackingInvalidateKey(robj *keyobj) {
+    if (TrackingTable == NULL || TrackingTableUsedSlots == 0) return;
+
+    sds sdskey = keyobj->ptr;
+    uint64_t hash = crc64(0,
+        (unsigned char*)sdskey,sdslen(sdskey))&(TRACKING_TABLE_SIZE-1);
+    trackingInvalidateSlot(hash);
+}
+
+/* This function is called when one or all the Redis databases are flushed
+ * (dbid == -1 in case of FLUSHALL). Caching slots are not specific for
+ * each DB but are global: currently what we do is sending a special
+ * notification to clients with tracking enabled, invalidating the caching
+ * slot "-1", which means, "all the keys", in order to avoid flooding clients
+ * with many invalidation messages for all the keys they may hold.
+ *
+ * However trying to flush the tracking table here is very costly:
+ * we need scanning 16 million caching slots in the table to check
+ * if they are used, this introduces a big delay. So what we do is to really
+ * flush the table in the case of FLUSHALL. When a FLUSHDB is called instead
+ * we just send the invalidation message to all the clients, but don't
+ * flush the table: it will slowly get garbage collected as more keys
+ * are modified in the used caching slots. */
+void trackingInvalidateKeysOnFlush(int dbid) {
+    if (server.tracking_clients) {
+        listNode *ln;
+        listIter li;
+        listRewind(server.clients,&li);
+        while ((ln = listNext(&li)) != NULL) {
+            client *c = listNodeValue(ln);
+            if (c->flags & CLIENT_TRACKING) {
+                sendTrackingMessage(c,-1);
+            }
+        }
+    }
+
+    /* In case of FLUSHALL, reclaim all the memory used by tracking. */
+    if (dbid == -1 && TrackingTable) {
+        for (int j = 0; j < TRACKING_TABLE_SIZE && TrackingTableUsedSlots > 0; j++) {
+            if (TrackingTable[j] != NULL) {
+                raxFree(TrackingTable[j]);
+                TrackingTable[j] = NULL;
+                TrackingTableUsedSlots--;
             }
-            c = redir;
-            using_redirection = 1;
         }
 
-        /* Only send such info for clients in RESP version 3 or more. However
-         * if redirection is active, and the connection we redirect to is
-         * in Pub/Sub mode, we can support the feature with RESP 2 as well,
-         * by sending Pub/Sub messages in the __redis__:invalidate channel. */
-        if (c->resp > 2) {
-            addReplyPushLen(c,2);
-            addReplyBulkCBuffer(c,"invalidate",10);
-            addReplyLongLong(c,hash);
-        } else if (using_redirection && c->flags & CLIENT_PUBSUB) {
-            robj *msg = createStringObjectFromLongLong(hash);
-            addReplyPubsubMessage(c,TrackingChannelName,msg);
-            decrRefCount(msg);
+        /* If there are no clients with tracking enabled, we can even
+         * reclaim the memory used by the table itself. The code assumes
+         * the table is allocated only if there is at least one client alive
+         * with tracking enabled. */
+        if (server.tracking_clients == 0) {
+            zfree(TrackingTable);
+            TrackingTable = NULL;
         }
     }
-    raxStop(&ri);
+}
 
-    /* Free the tracking table: we'll create the radix tree and populate it
-     * again if more keys will be modified in this hash slot. */
-    raxFree(TrackingTable[hash]);
-    TrackingTable[hash] = NULL;
+/* Tracking forces Redis to remember information about which client may have
+ * keys about certian caching slots. In workloads where there are a lot of
+ * reads, but keys are hardly modified, the amount of information we have
+ * to remember server side could be a lot: for each 16 millions of caching
+ * slots we may end with a radix tree containing many entries.
+ *
+ * So Redis allows the user to configure a maximum fill rate for the
+ * invalidation table. This function makes sure that we don't go over the
+ * specified fill rate: if we are over, we can just evict informations about
+ * random caching slots, and send invalidation messages to clients like if
+ * the key was modified. */
+void trackingLimitUsedSlots(void) {
+    static unsigned int timeout_counter = 0;
+
+    if (server.tracking_table_max_fill == 0) return; /* No limits set. */
+    unsigned int max_slots =
+        (TRACKING_TABLE_SIZE/100) * server.tracking_table_max_fill;
+    if (TrackingTableUsedSlots <= max_slots) {
+        timeout_counter = 0;
+        return; /* Limit not reached. */
+    }
+
+    /* We have to invalidate a few slots to reach the limit again. The effort
+     * we do here is proportional to the number of times we entered this
+     * function and found that we are still over the limit. */
+    int effort = 100 * (timeout_counter+1);
+
+    /* Let's start at a random position, and perform linear probing, in order
+     * to improve cache locality. However once we are able to find an used
+     * slot, jump again randomly, in order to avoid creating big holes in the
+     * table (that will make this funciton use more resourced later). */
+    while(effort > 0) {
+        unsigned int idx = rand() % TRACKING_TABLE_SIZE;
+        do {
+            effort--;
+            idx = (idx+1) % TRACKING_TABLE_SIZE;
+            if (TrackingTable[idx] != NULL) {
+                trackingInvalidateSlot(idx);
+                if (TrackingTableUsedSlots <= max_slots) {
+                    timeout_counter = 0;
+                    return; /* Return ASAP: we are again under the limit. */
+                } else {
+                    break; /* Jump to next random position. */
+                }
+            }
+        } while(effort > 0);
+    }
+    timeout_counter++;
+}
+
+/* This is just used in order to access the amount of used slots in the
+ * tracking table. */
+unsigned long long trackingGetUsedSlots(void) {
+    return TrackingTableUsedSlots;
 }
diff --git a/tests/integration/replication.tcl b/tests/integration/replication.tcl
index d69a1761a..5d32555b0 100644
--- a/tests/integration/replication.tcl
+++ b/tests/integration/replication.tcl
@@ -192,12 +192,6 @@ foreach mdl {no yes} {
             set master_host [srv 0 host]
             set master_port [srv 0 port]
             set slaves {}
-            set load_handle0 [start_bg_complex_data $master_host $master_port 9 100000000]
-            set load_handle1 [start_bg_complex_data $master_host $master_port 11 100000000]
-            set load_handle2 [start_bg_complex_data $master_host $master_port 12 100000000]
-            set load_handle3 [start_write_load $master_host $master_port 8]
-            set load_handle4 [start_write_load $master_host $master_port 4]
-            after 5000 ;# wait for some data to accumulate so that we have RDB part for the fork
             start_server {} {
                 lappend slaves [srv 0 client]
                 start_server {} {
@@ -205,6 +199,14 @@ foreach mdl {no yes} {
                     start_server {} {
                         lappend slaves [srv 0 client]
                         test "Connect multiple replicas at the same time (issue #141), master diskless=$mdl, replica diskless=$sdl" {
+                            # start load handles only inside the test, so that the test can be skipped
+                            set load_handle0 [start_bg_complex_data $master_host $master_port 9 100000000]
+                            set load_handle1 [start_bg_complex_data $master_host $master_port 11 100000000]
+                            set load_handle2 [start_bg_complex_data $master_host $master_port 12 100000000]
+                            set load_handle3 [start_write_load $master_host $master_port 8]
+                            set load_handle4 [start_write_load $master_host $master_port 4]
+                            after 5000 ;# wait for some data to accumulate so that we have RDB part for the fork
+
                             # Send SLAVEOF commands to slaves
                             [lindex $slaves 0] config set repl-diskless-load $sdl
                             [lindex $slaves 1] config set repl-diskless-load $sdl
@@ -278,9 +280,9 @@ start_server {tags {"repl"}} {
     set master [srv 0 client]
     set master_host [srv 0 host]
     set master_port [srv 0 port]
-    set load_handle0 [start_write_load $master_host $master_port 3]
     start_server {} {
         test "Master stream is correctly processed while the replica has a script in -BUSY state" {
+            set load_handle0 [start_write_load $master_host $master_port 3]
             set slave [srv 0 client]
             $slave config set lua-time-limit 500
             $slave slaveof $master_host $master_port
@@ -383,3 +385,84 @@ test {slave fails full sync and diskless load swapdb recoveres it} {
         }
     }
 }
+
+test {diskless loading short read} {
+    start_server {tags {"repl"}} {
+        set replica [srv 0 client]
+        set replica_host [srv 0 host]
+        set replica_port [srv 0 port]
+        start_server {} {
+            set master [srv 0 client]
+            set master_host [srv 0 host]
+            set master_port [srv 0 port]
+
+            # Set master and replica to use diskless replication
+            $master config set repl-diskless-sync yes
+            $master config set rdbcompression no
+            $replica config set repl-diskless-load swapdb
+            # Try to fill the master with all types of data types / encodings
+            for {set k 0} {$k < 3} {incr k} {
+                for {set i 0} {$i < 10} {incr i} {
+                    r set "$k int_$i" [expr {int(rand()*10000)}]
+                    r expire "$k int_$i" [expr {int(rand()*10000)}]
+                    r set "$k string_$i" [string repeat A [expr {int(rand()*1000000)}]]
+                    r hset "$k hash_small" [string repeat A [expr {int(rand()*10)}]]  0[string repeat A [expr {int(rand()*10)}]]
+                    r hset "$k hash_large" [string repeat A [expr {int(rand()*10000)}]] [string repeat A [expr {int(rand()*1000000)}]]
+                    r sadd "$k set_small" [string repeat A [expr {int(rand()*10)}]]
+                    r sadd "$k set_large" [string repeat A [expr {int(rand()*1000000)}]]
+                    r zadd "$k zset_small" [expr {rand()}] [string repeat A [expr {int(rand()*10)}]]
+                    r zadd "$k zset_large" [expr {rand()}] [string repeat A [expr {int(rand()*1000000)}]]
+                    r lpush "$k list_small" [string repeat A [expr {int(rand()*10)}]]
+                    r lpush "$k list_large" [string repeat A [expr {int(rand()*1000000)}]]
+                    for {set j 0} {$j < 10} {incr j} {
+                        r xadd "$k stream" * foo "asdf" bar "1234"
+                    }
+                    r xgroup create "$k stream" "mygroup_$i" 0
+                    r xreadgroup GROUP "mygroup_$i" Alice COUNT 1 STREAMS "$k stream" >
+                }
+            }
+
+            # Start the replication process...
+            $master config set repl-diskless-sync-delay 0
+            $replica replicaof $master_host $master_port
+
+            # kill the replication at various points
+            set attempts 3
+            if {$::accurate} { set attempts 10 }
+            for {set i 0} {$i < $attempts} {incr i} {
+                # wait for the replica to start reading the rdb
+                # using the log file since the replica only responds to INFO once in 2mb
+                wait_for_log_message -1 "*Loading DB in memory*" 5 2000 1
+
+                # add some additional random sleep so that we kill the master on a different place each time
+                after [expr {int(rand()*100)}]
+
+                # kill the replica connection on the master
+                set killed [$master client kill type replica]
+
+                if {[catch {
+                    set res [wait_for_log_message -1 "*Internal error in RDB*" 5 100 10]
+                    if {$::verbose} {
+                        puts $res
+                    }
+                }]} {
+                    puts "failed triggering short read"
+                    # force the replica to try another full sync
+                    $master client kill type replica
+                    $master set asdf asdf
+                    # the side effect of resizing the backlog is that it is flushed (16k is the min size)
+                    $master config set repl-backlog-size [expr {16384 + $i}]
+                }
+                # wait for loading to stop (fail)
+                wait_for_condition 100 10 {
+                    [s -1 loading] eq 0
+                } else {
+                    fail "Replica didn't disconnect"
+                }
+            }
+            # enable fast shutdown
+            $master config set rdb-key-save-delay 0
+        }
+    }
+}
+
diff --git a/tests/modules/Makefile b/tests/modules/Makefile
index 014d20afa..6e4574747 100644
--- a/tests/modules/Makefile
+++ b/tests/modules/Makefile
@@ -13,12 +13,16 @@ endif
 
 .SUFFIXES: .c .so .xo .o
 
-all: commandfilter.so
+all: commandfilter.so testrdb.so
 
 .c.xo:
 	$(CC) -I../../src $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
 
 commandfilter.xo: ../../src/redismodule.h
+testrdb.xo: ../../src/redismodule.h
 
 commandfilter.so: commandfilter.xo
 	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
+testrdb.so: testrdb.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
diff --git a/tests/modules/testrdb.c b/tests/modules/testrdb.c
new file mode 100644
index 000000000..415497a2f
--- /dev/null
+++ b/tests/modules/testrdb.c
@@ -0,0 +1,229 @@
+#include "redismodule.h"
+
+#include <string.h>
+#include <assert.h>
+
+/* Module configuration, save aux or not? */
+long long conf_aux_count = 0;
+
+/* Registered type */
+RedisModuleType *testrdb_type = NULL;
+
+/* Global values to store and persist to aux */
+RedisModuleString *before_str = NULL;
+RedisModuleString *after_str = NULL;
+
+void *testrdb_type_load(RedisModuleIO *rdb, int encver) {
+    int count = RedisModule_LoadSigned(rdb);
+    assert(count==1);
+    assert(encver==1);
+    RedisModuleString *str = RedisModule_LoadString(rdb);
+    return str;
+}
+
+void testrdb_type_save(RedisModuleIO *rdb, void *value) {
+    RedisModuleString *str = (RedisModuleString*)value;
+    RedisModule_SaveSigned(rdb, 1);
+    RedisModule_SaveString(rdb, str);
+}
+
+void testrdb_aux_save(RedisModuleIO *rdb, int when) {
+    if (conf_aux_count==1) assert(when == REDISMODULE_AUX_AFTER_RDB);
+    if (conf_aux_count==0) assert(0);
+    if (when == REDISMODULE_AUX_BEFORE_RDB) {
+        if (before_str) {
+            RedisModule_SaveSigned(rdb, 1);
+            RedisModule_SaveString(rdb, before_str);
+        } else {
+            RedisModule_SaveSigned(rdb, 0);
+        }
+    } else {
+        if (after_str) {
+            RedisModule_SaveSigned(rdb, 1);
+            RedisModule_SaveString(rdb, after_str);
+        } else {
+            RedisModule_SaveSigned(rdb, 0);
+        }
+    }
+}
+
+int testrdb_aux_load(RedisModuleIO *rdb, int encver, int when) {
+    assert(encver == 1);
+    if (conf_aux_count==1) assert(when == REDISMODULE_AUX_AFTER_RDB);
+    if (conf_aux_count==0) assert(0);
+    RedisModuleCtx *ctx = RedisModule_GetContextFromIO(rdb);
+    if (when == REDISMODULE_AUX_BEFORE_RDB) {
+        if (before_str)
+            RedisModule_FreeString(ctx, before_str);
+        before_str = NULL;
+        int count = RedisModule_LoadSigned(rdb);
+        if (count)
+            before_str = RedisModule_LoadString(rdb);
+    } else {
+        if (after_str)
+            RedisModule_FreeString(ctx, after_str);
+        after_str = NULL;
+        int count = RedisModule_LoadSigned(rdb);
+        if (count)
+            after_str = RedisModule_LoadString(rdb);
+    }
+    return REDISMODULE_OK;
+}
+
+void testrdb_type_free(void *value) {
+    RedisModule_FreeString(NULL, (RedisModuleString*)value);
+}
+
+int testrdb_set_before(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 2) {
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+
+    if (before_str)
+        RedisModule_FreeString(ctx, before_str);
+    before_str = argv[1];
+    RedisModule_RetainString(ctx, argv[1]);
+    RedisModule_ReplyWithLongLong(ctx, 1);
+    return REDISMODULE_OK;
+}
+
+int testrdb_get_before(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    REDISMODULE_NOT_USED(argv);
+    if (argc != 1){
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+    if (before_str)
+        RedisModule_ReplyWithString(ctx, before_str);
+    else
+        RedisModule_ReplyWithStringBuffer(ctx, "", 0);
+    return REDISMODULE_OK;
+}
+
+int testrdb_set_after(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 2){
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+
+    if (after_str)
+        RedisModule_FreeString(ctx, after_str);
+    after_str = argv[1];
+    RedisModule_RetainString(ctx, argv[1]);
+    RedisModule_ReplyWithLongLong(ctx, 1);
+    return REDISMODULE_OK;
+}
+
+int testrdb_get_after(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    REDISMODULE_NOT_USED(argv);
+    if (argc != 1){
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+    if (after_str)
+        RedisModule_ReplyWithString(ctx, after_str);
+    else
+        RedisModule_ReplyWithStringBuffer(ctx, "", 0);
+    return REDISMODULE_OK;
+}
+
+int testrdb_set_key(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 3){
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx, argv[1], REDISMODULE_WRITE);
+    RedisModuleString *str = RedisModule_ModuleTypeGetValue(key);
+    if (str)
+        RedisModule_FreeString(ctx, str);
+    RedisModule_ModuleTypeSetValue(key, testrdb_type, argv[2]);
+    RedisModule_RetainString(ctx, argv[2]);
+    RedisModule_CloseKey(key);
+    RedisModule_ReplyWithLongLong(ctx, 1);
+    return REDISMODULE_OK;
+}
+
+int testrdb_get_key(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 2){
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx, argv[1], REDISMODULE_WRITE);
+    RedisModuleString *str = RedisModule_ModuleTypeGetValue(key);
+    RedisModule_CloseKey(key);
+    RedisModule_ReplyWithString(ctx, str);
+    return REDISMODULE_OK;
+}
+
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
+    if (RedisModule_Init(ctx,"testrdb",1,REDISMODULE_APIVER_1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (argc > 0)
+        RedisModule_StringToLongLong(argv[0], &conf_aux_count);
+
+    if (conf_aux_count==0) {
+        RedisModuleTypeMethods datatype_methods = {
+            .version = 1,
+            .rdb_load = testrdb_type_load,
+            .rdb_save = testrdb_type_save,
+            .aof_rewrite = NULL,
+            .digest = NULL,
+            .free = testrdb_type_free,
+        };
+
+        testrdb_type = RedisModule_CreateDataType(ctx, "test__rdb", 1, &datatype_methods);
+        if (testrdb_type == NULL)
+            return REDISMODULE_ERR;
+    } else {
+        RedisModuleTypeMethods datatype_methods = {
+            .version = REDISMODULE_TYPE_METHOD_VERSION,
+            .rdb_load = testrdb_type_load,
+            .rdb_save = testrdb_type_save,
+            .aof_rewrite = NULL,
+            .digest = NULL,
+            .free = testrdb_type_free,
+            .aux_load = testrdb_aux_load,
+            .aux_save = testrdb_aux_save,
+            .aux_save_triggers = (conf_aux_count == 1 ?
+                                  REDISMODULE_AUX_AFTER_RDB :
+                                  REDISMODULE_AUX_BEFORE_RDB | REDISMODULE_AUX_AFTER_RDB)
+        };
+
+        testrdb_type = RedisModule_CreateDataType(ctx, "test__rdb", 1, &datatype_methods);
+        if (testrdb_type == NULL)
+            return REDISMODULE_ERR;
+    }
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.set.before", testrdb_set_before,"deny-oom",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.get.before", testrdb_get_before,"",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.set.after", testrdb_set_after,"deny-oom",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.get.after", testrdb_get_after,"",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.set.key", testrdb_set_key,"deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"testrdb.get.key", testrdb_get_key,"",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}
diff --git a/tests/support/util.tcl b/tests/support/util.tcl
index 41cc5612a..c2e76afad 100644
--- a/tests/support/util.tcl
+++ b/tests/support/util.tcl
@@ -99,6 +99,25 @@ proc wait_for_ofs_sync {r1 r2} {
     }
 }
 
+proc wait_for_log_message {srv_idx pattern last_lines maxtries delay} {
+    set retry $maxtries
+    set stdout [srv $srv_idx stdout]
+    while {$retry} {
+        set result [exec tail -$last_lines < $stdout]
+        set result [split $result "\n"]
+        foreach line $result {
+            if {[string match $pattern $line]} {
+                return $line
+            }
+        }
+        incr retry -1
+        after $delay
+    }
+    if {$retry == 0} {
+        fail "log message of '$pattern' not found"
+    }
+}
+
 # Random integer between 0 and max (excluded).
 proc randomInt {max} {
     expr {int(rand()*$max)}
diff --git a/tests/unit/geo.tcl b/tests/unit/geo.tcl
index 604697be4..49e421ee9 100644
--- a/tests/unit/geo.tcl
+++ b/tests/unit/geo.tcl
@@ -61,6 +61,7 @@ set regression_vectors {
     {939895 151 59.149620271823181 65.204186651485145}
     {1412 156 149.29737817929004 15.95807862745508}
     {564862 149 84.062063109158544 -65.685403922426232}
+    {1546032440391 16751 -1.8175081637769495 20.665668878082954}
 }
 set rv_idx 0
 
@@ -274,8 +275,19 @@ start_server {tags {"geo"}} {
                 foreach place $diff {
                     set mydist [geo_distance $lon $lat $search_lon $search_lat]
                     set mydist [expr $mydist/1000]
-                    if {($mydist / $radius_km) > 0.999} {incr rounding_errors}
+                    if {($mydist / $radius_km) > 0.999} {
+                        incr rounding_errors
+                        continue
+                    }
+                    if {$mydist < $radius_m} {
+                        # This is a false positive for redis since given the 
+                        # same points the higher precision calculation provided 
+                        # by TCL shows the point within range
+                        incr rounding_errors
+                        continue
+                    }
                 }
+
                 # Make sure this is a real error and not a rounidng issue.
                 if {[llength $diff] == $rounding_errors} {
                     set res $res2; # Error silenced
diff --git a/tests/unit/moduleapi/testrdb.tcl b/tests/unit/moduleapi/testrdb.tcl
new file mode 100644
index 000000000..22201a08e
--- /dev/null
+++ b/tests/unit/moduleapi/testrdb.tcl
@@ -0,0 +1,62 @@
+set testmodule [file normalize tests/modules/testrdb.so]
+
+proc restart_and_wait {} {
+    catch {
+        r debug restart
+    }
+
+    # wait for the server to come back up
+    set retry 50
+    while {$retry} {
+        if {[catch { r ping }]} {
+            after 100
+        } else {
+            break
+        }
+        incr retry -1
+    }
+}
+
+tags "modules" {
+    start_server [list overrides [list loadmodule "$testmodule"]] {
+        test {modules are able to persist types} {
+            r testrdb.set.key key1 value1
+            assert_equal "value1" [r testrdb.get.key key1]
+            r debug reload
+            assert_equal "value1" [r testrdb.get.key key1]
+        }
+
+        test {modules global are lost without aux} {
+            r testrdb.set.before global1
+            assert_equal "global1" [r testrdb.get.before]
+            restart_and_wait
+            assert_equal "" [r testrdb.get.before]
+        }
+    }
+
+    start_server [list overrides [list loadmodule "$testmodule 2"]] {
+        test {modules are able to persist globals before and after} {
+            r testrdb.set.before global1
+            r testrdb.set.after global2
+            assert_equal "global1" [r testrdb.get.before]
+            assert_equal "global2" [r testrdb.get.after]
+            restart_and_wait
+            assert_equal "global1" [r testrdb.get.before]
+            assert_equal "global2" [r testrdb.get.after]
+        }
+
+    }
+
+    start_server [list overrides [list loadmodule "$testmodule 1"]] {
+        test {modules are able to persist globals just after} {
+            r testrdb.set.after global2
+            assert_equal "global2" [r testrdb.get.after]
+            restart_and_wait
+            assert_equal "global2" [r testrdb.get.after]
+        }
+    }
+
+
+    # TODO: test short read handling
+
+}