diff options
Diffstat (limited to 'src/replication.c')
| -rw-r--r-- | src/replication.c | 65 |
1 files changed, 28 insertions, 37 deletions
diff --git a/src/replication.c b/src/replication.c index 99f233380..12500c0af 100644 --- a/src/replication.c +++ b/src/replication.c @@ -39,7 +39,6 @@ #include <sys/socket.h> #include <sys/stat.h> -long long adjustMeaningfulReplOffset(); void replicationDiscardCachedMaster(void); void replicationResurrectCachedMaster(connection *conn); void replicationSendAck(void); @@ -2755,10 +2754,6 @@ void replicationCacheMaster(client *c) { * pending outputs to the master. */ sdsclear(server.master->querybuf); sdsclear(server.master->pending_querybuf); - - /* Adjust reploff and read_reploff to the last meaningful offset we - * executed. This is the offset the replica will use for future PSYNC. */ - server.master->reploff = adjustMeaningfulReplOffset(); server.master->read_reploff = server.master->reploff; if (c->flags & CLIENT_MULTI) discardTransaction(c); listEmpty(c->reply); @@ -2783,15 +2778,33 @@ void replicationCacheMaster(client *c) { replicationHandleMasterDisconnection(); } -/* If the "meaningful" offset, that is the offset without the final PINGs - * in the stream, is different than the last offset, use it instead: - * often when the master is no longer reachable, replicas will never - * receive the PINGs, however the master will end with an incremented - * offset because of the PINGs and will not be able to incrementally - * PSYNC with the new master. - * This function trims the replication backlog when needed, and returns - * the offset to be used for future partial sync. */ -long long adjustMeaningfulReplOffset() { +/* This function is called when a master is turend into a slave, in order to + * create from scratch a cached master for the new client, that will allow + * to PSYNC with the slave that was promoted as the new master after a + * failover. + * + * Assuming this instance was previously the master instance of the new master, + * the new master will accept its replication ID, and potentiall also the + * current offset if no data was lost during the failover. So we use our + * current replication ID and offset in order to synthesize a cached master. */ +void replicationCacheMasterUsingMyself(void) { + serverLog(LL_NOTICE, + "Before turning into a replica, using my own master parameters " + "to synthesize a cached master: I may be able to synchronize with " + "the new master with just a partial transfer."); + + /* This will be used to populate the field server.master->reploff + * by replicationCreateMasterClient(). We'll later set the created + * master as server.cached_master, so the replica will use such + * offset for PSYNC. */ + server.master_initial_offset = server.master_repl_offset; + + /* However if the "meaningful" offset, that is the offset without + * the final PINGs in the stream, is different, use this instead: + * often when the master is no longer reachable, replicas will never + * receive the PINGs, however the master will end with an incremented + * offset because of the PINGs and will not be able to incrementally + * PSYNC with the new master. */ if (server.master_repl_offset > server.master_repl_meaningful_offset) { long long delta = server.master_repl_offset - server.master_repl_meaningful_offset; @@ -2801,6 +2814,7 @@ long long adjustMeaningfulReplOffset() { server.master_repl_meaningful_offset, server.master_repl_offset, delta); + server.master_initial_offset = server.master_repl_meaningful_offset; server.master_repl_offset = server.master_repl_meaningful_offset; if (server.repl_backlog_histlen <= delta) { server.repl_backlog_histlen = 0; @@ -2812,29 +2826,6 @@ long long adjustMeaningfulReplOffset() { server.repl_backlog_size; } } - return server.master_repl_offset; -} - -/* This function is called when a master is turend into a slave, in order to - * create from scratch a cached master for the new client, that will allow - * to PSYNC with the slave that was promoted as the new master after a - * failover. - * - * Assuming this instance was previously the master instance of the new master, - * the new master will accept its replication ID, and potentiall also the - * current offset if no data was lost during the failover. So we use our - * current replication ID and offset in order to synthesize a cached master. */ -void replicationCacheMasterUsingMyself(void) { - serverLog(LL_NOTICE, - "Before turning into a replica, using my own master parameters " - "to synthesize a cached master: I may be able to synchronize with " - "the new master with just a partial transfer."); - - /* This will be used to populate the field server.master->reploff - * by replicationCreateMasterClient(). We'll later set the created - * master as server.cached_master, so the replica will use such - * offset for PSYNC. */ - server.master_initial_offset = adjustMeaningfulReplOffset(); /* The master client we create can be set to any DBID, because * the new master will start its replication stream with SELECT. */ |