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Aug
4
awarded  Constituent
Aug
4
awarded  Caucus
Jul
29
comment MySQL instance stalling “doing SYNC index”
@RickJames BTW, this specific application indeed does benefit from the large size of the query cache without hitting the query cache lock contention problem described elsewhere. The query_cache_min_res_unit has been set to 16K to reduce fragmentation. The total RAM size assigned to the VM was 36 GB.
Jul
29
comment MySQL instance stalling “doing SYNC index”
@RickJames nice to see you here dealing with my question, thank you for your time. However, Daniel has already posted what seems a definite workaround to the problem and I just wanted to reward his work with a bounty.
Jul
28
accepted MySQL instance stalling “doing SYNC index”
Jul
28
comment MySQL instance stalling “doing SYNC index”
I do wonder how it could go unnoticed for such a long time. Surely, there are more people running InnoDB with FTS and binlog enabled on non-SSD-storage?
Jul
28
comment MySQL instance stalling “doing SYNC index”
This looks very much like it could be the resolution for the issue I was seeing, too. How did you come up with the workaround? Also, in my case the full text index would have fit into the buffer pool (which is ~30G in size) but the operation seemed to be heavily latency-bound. I am under the impression that MySQL's I/O stack is extremely inefficient when dealing with storage latency, so this issue probably is a combination of both - the inefficiency along with a bad default for binary logging configurations.
Dec
4
comment stress-testing MySQL slave with master's queries
@phil_w I have seen the tcpdump capture option in the docs, but the pacing-relevant option is saying This option ensures that each query takes at least Query_time (from slow query log) to execute, which, I assume, means that it won't be able to make use of tcpdump caps. Also, pcap data is even more difficult to pre-process than the slow query log.
Dec
4
comment stress-testing MySQL slave with master's queries
@RolandoMySQLDBA thanks for pointing to your posts. I did search the site already and stumbled upon most of the answers you're referencing. Unfortunately, none of them is addressing both of the issues mentioned above, which is in fact why I am asking.
Dec
3
asked stress-testing MySQL slave with master's queries
Dec
2
awarded  Notable Question
Nov
7
awarded  Popular Question
Oct
2
comment Sudden periods of performance degradation
The older release might have bugs and performance-related issues which have been fixed in the newer release and thus were not visible prior to the role-swap. As replication is asymmetric and slave-initiated, an older slave is not going to affect the master performance-wise.
Oct
2
comment Sudden periods of performance degradation
Possibly related: dba.stackexchange.com/questions/75439/…. You can take a look at what has been done for diagnosis so you could use this in your own setup even if the premise of full-text search indexes does not apply to your setup.
Sep
24
awarded  Autobiographer
Sep
6
comment MySQL - HOWTO speed up slave replication on large database / Quickly spawn slave?
The increasing replication lag might be due to replication errors. You should check your mysql server's error.log files and double-check that you have your IDs (server-id and, if applicable, server-uuid) are indeed unique throughout your replication topology.
Sep
5
revised MySQL instance stalling “doing SYNC index”
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Sep
5
revised MySQL instance stalling “doing SYNC index”
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Sep
5
revised MySQL instance stalling “doing SYNC index”
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Sep
5
revised MySQL instance stalling “doing SYNC index”
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