From c8c1006cf4dd01ae8df844ae2c8fe36ca1bff5bc Mon Sep 17 00:00:00 2001 From: antirez Date: Fri, 4 Oct 2013 12:25:09 +0200 Subject: [PATCH] PSYNC: safer handling of PSYNC requests. There was a bug that over-esteemed the amount of backlog available, however this could only happen when a slave was asking for an offset that was in the "future" compared to the master replication backlog. Now this case is handled well and logged as an incident in the master log file. --- src/replication.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/replication.c b/src/replication.c index 3abfdf160a..2652b29332 100644 --- a/src/replication.c +++ b/src/replication.c @@ -356,10 +356,14 @@ int masterTryPartialResynchronization(redisClient *c) { REDIS_OK) goto need_full_resync; if (!server.repl_backlog || psync_offset < server.repl_backlog_off || - psync_offset >= (server.repl_backlog_off + server.repl_backlog_size)) + psync_offset > (server.repl_backlog_off + server.repl_backlog_histlen)) { redisLog(REDIS_NOTICE, "Unable to partial resync with the slave for lack of backlog (Slave request was: %lld).", psync_offset); + if (psync_offset > server.master_repl_offset) { + redisLog(REDIS_WARNING, + "Warning: slave tried to PSYNC with an offset that is greater than the master replication offset."); + } goto need_full_resync; }