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| author | zhaozhao.zz <zhaozhao.zz@alibaba-inc.com> | 2017-11-01 17:32:23 +0800 |
|---|---|---|
| committer | antirez <antirez@gmail.com> | 2017-11-24 11:09:14 +0100 |
| commit | 9f69e179cf7c7e985855babaf894eb600a54edb1 (patch) | |
| tree | 3351e02af1f3dd73a93201ab90129e059a5867a6 | |
| parent | 0205dd01e2d0180474c24aceae0a51e6a3862e64 (diff) | |
| download | redis-9f69e179cf7c7e985855babaf894eb600a54edb1.tar.gz | |
PSYNC2: safe free backlog when reach the time limit
When we free the backlog, we should use a new
replication ID and clear the ID2. Since without
backlog we can not increment master_repl_offset
even do write commands, that may lead to inconsistency
when we try to connect a "slave-before" master
(if this master is our slave before, our replid
equals the master's replid2). As the master have our
history, so we can match the master's replid2 and
second_replid_offset, that make partial sync work,
but the data is inconsistent.
| -rw-r--r-- | src/replication.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/replication.c b/src/replication.c index e0b3d910e..fe7b0f739 100644 --- a/src/replication.c +++ b/src/replication.c @@ -2613,6 +2613,18 @@ void replicationCron(void) { time_t idle = server.unixtime - server.repl_no_slaves_since; if (idle > server.repl_backlog_time_limit) { + /* When we free the backlog, we always use a new + * replication ID and clear the ID2. Since without + * backlog we can not increment master_repl_offset + * even do write commands, that may lead to inconsistency + * when we try to connect a "slave-before" master + * (if this master is our slave before, our replid + * equals the master's replid2). As the master have our + * history, so we can match the master's replid2 and + * second_replid_offset, that make partial sync work, + * but the data is inconsistent. */ + changeReplicationId(); + clearReplicationId2(); freeReplicationBacklog(); serverLog(LL_NOTICE, "Replication backlog freed after %d seconds " |