MW-267 Enforce wsrep_max_ws_size limit in wsrep provider

This changes variable wsrep_max_ws_size so that its value
is linked to the value of provider option repl.max_ws_size.
That is, changing the value of variable wsrep_max_ws_size
will change the value of provider option repl.max_ws_size,
and viceversa.
The writeset size limit is always enforced in the provider,
regardless of which option is used.

5 files changed, 53 insertions, 14 deletions

diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 0bfa0bf5eb0..0ac8d40fbae 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -4688,8 +4688,9 @@ static Sys_var_charptr Sys_wsrep_start_position (
 static Sys_var_ulong Sys_wsrep_max_ws_size (
        "wsrep_max_ws_size", "Max write set size (bytes)",
        GLOBAL_VAR(wsrep_max_ws_size), CMD_LINE(REQUIRED_ARG),
-       /* Upper limit is 65K short of 4G to avoid overlows on 32-bit systems */
-       VALID_RANGE(1024, WSREP_MAX_WS_SIZE), DEFAULT(1073741824UL), BLOCK_SIZE(1));
+       VALID_RANGE(1024, WSREP_MAX_WS_SIZE), DEFAULT(WSREP_MAX_WS_SIZE),
+       BLOCK_SIZE(1), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
+       ON_UPDATE(wsrep_max_ws_size_update));
 
 static Sys_var_ulong Sys_wsrep_max_ws_rows (
        "wsrep_max_ws_rows", "Max number of rows in write set",
diff --git a/sql/wsrep_applier.cc b/sql/wsrep_applier.cc
index 90c84f1c2cc..73a43185162 100644
--- a/sql/wsrep_applier.cc
+++ b/sql/wsrep_applier.cc
@@ -39,15 +39,9 @@ static Log_event* wsrep_read_log_event(
   const char *error= 0;
   Log_event *res=  0;
 
-  if (data_len > wsrep_max_ws_size)
-  {
-    error = "Event too big";
-    goto err;
-  }
-
-  res= Log_event::read_log_event(buf, data_len, &error, description_event, true);
+  res= Log_event::read_log_event(buf, data_len, &error, description_event,
+                                 true);
 
-err:
   if (!res)
   {
     DBUG_ASSERT(error != 0);
diff --git a/sql/wsrep_binlog.h b/sql/wsrep_binlog.h
index a7b680f616b..c29d51caf2c 100644
--- a/sql/wsrep_binlog.h
+++ b/sql/wsrep_binlog.h
@@ -19,7 +19,7 @@
 #include "sql_class.h" // THD, IO_CACHE
 
 #define HEAP_PAGE_SIZE 65536 /* 64K */
-#define WSREP_MAX_WS_SIZE (0xFFFFFFFFUL - HEAP_PAGE_SIZE)
+#define WSREP_MAX_WS_SIZE 2147483647 /* 2GB */
 
 /*
   Write the contents of a cache to a memory buffer.
diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
index 7ac68df66bd..44d17e3e78a 100644
--- a/sql/wsrep_var.cc
+++ b/sql/wsrep_var.cc
@@ -179,6 +179,32 @@ void wsrep_start_position_init (const char* val)
   wsrep_set_local_position (val, false);
 }
 
+static int get_provider_option_value(const char* opts,
+                                     const char* opt_name,
+                                     ulong* opt_value)
+{
+  int ret= 1;
+  ulong opt_value_tmp;
+  char *opt_value_str, *s, *opts_copy= my_strdup(opts, MYF(MY_WME));
+
+  if ((opt_value_str= strstr(opts_copy, opt_name)) == NULL)
+    goto end;
+  opt_value_str= strtok_r(opt_value_str, "=", &s);
+  if (opt_value_str == NULL) goto end;
+  opt_value_str= strtok_r(NULL, ";", &s);
+  if (opt_value_str == NULL) goto end;
+
+  opt_value_tmp= strtoul(opt_value_str, NULL, 10);
+  if (errno == ERANGE) goto end;
+
+  *opt_value= opt_value_tmp;
+  ret= 0;
+
+end:
+  my_free(opts_copy);
+  return ret;
+}
+
 static bool refresh_provider_options()
 {
   WSREP_DEBUG("refresh_provider_options: %s", 
@@ -186,9 +212,10 @@ static bool refresh_provider_options()
   char* opts= wsrep->options_get(wsrep);
   if (opts)
   {
-    if (wsrep_provider_options) my_free((void *)wsrep_provider_options);
-    wsrep_provider_options = (char*)my_memdup(opts, strlen(opts) + 1, 
-                                              MYF(MY_WME));
+    wsrep_provider_options_init(opts);
+    get_provider_option_value(wsrep_provider_options,
+                              (char*)"repl.max_ws_size",
+                              &wsrep_max_ws_size);
   }
   else
   {
@@ -531,6 +558,21 @@ bool wsrep_desync_update (sys_var *self, THD* thd, enum_var_type type)
   return false;
 }
 
+bool wsrep_max_ws_size_update (sys_var *self, THD *thd, enum_var_type)
+{
+  char max_ws_size_opt[128];
+  my_snprintf(max_ws_size_opt, sizeof(max_ws_size_opt),
+              "repl.max_ws_size=%d", wsrep_max_ws_size);
+  wsrep_status_t ret= wsrep->options_set(wsrep, max_ws_size_opt);
+  if (ret != WSREP_OK)
+  {
+    WSREP_ERROR("Set options returned %d", ret);
+    refresh_provider_options();
+    return true;
+  }
+  return refresh_provider_options();
+}
+
 /*
  * Status variables stuff below
  */
diff --git a/sql/wsrep_var.h b/sql/wsrep_var.h
index 524dabfd9c0..f72df9d098a 100644
--- a/sql/wsrep_var.h
+++ b/sql/wsrep_var.h
@@ -83,4 +83,6 @@ extern bool wsrep_slave_threads_update       UPDATE_ARGS;
 extern bool wsrep_desync_check               CHECK_ARGS;
 extern bool wsrep_desync_update              UPDATE_ARGS;
 
+extern bool wsrep_max_ws_size_update         UPDATE_ARGS;
+
 #endif /* WSREP_VAR_H */