MySQL Performance: MySQL => odd replication lag situation

odd replication lag situation [message #3643]

Tue, 21 October 2008 06:41

mancdaz
Messages: 5
Registered: March 2008

Junior Member

OK,

I have 4 servers - 1 master and 3 slaves. The 3 slaves are identical in their hardware specs and setup.

slave1 and slave2 are doing more work than slave3, but still I see frequent (every 10 seconds) lag in replication on slave3, where I see none on slave1 and 2.

Even if all the work that slave4 does is pointed at slave1 and 2 on top of their normal workload, they still show zero lag.

So this isn't a question about how to fight replication lag in general, which has been covered a lot. It's a question about how to check what on this particular server is causing the lags.

The ONLY difference I know of is that the first to are running 5.0.51a, and 3 is running 5.0.67. I tried to check the changelogs to see if there has been a change in the way lag is calculated and reported, but can see nothing. Also, it's real lag (the app sees it) as opposed to just lag being reported differently.

Any help much appreciated

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