Today my Master DB server (MySQL 5.5) suddenly started failing to write to binary log files. All INSERT and UPDATE queries gets a “query end” status, and then it doesn’t release the connection.
I found a couple of related topics on StackOverflow, but the only way I was able to fix the issue was to set sync_binlog to 0. Now it seems that most queries are never even being written to the binary logs, which is not good for replication.
The most likely reason would be due to some file system related issue (such as full drive, etc.), but everything seems to check out.