|To:||"'Tomas Vondra'" <tv(at)fuzzy(dot)cz>, "'Vitalii Tymchyshyn'" <tivv00(at)gmail(dot)com>|
|Subject:||Re: Write workload is causing severe slowdown in Production|
|Views:||Raw Message | Whole Thread | Download mbox|
> There's a checkpoint_warning option. Set it to 3600 and you should get
> messages in the log. Correlate those to the issues (do they happen at the
> same time?).
After setting "checkpoint_warning" to 3600, can you explain on how do I correlate with the messages?
> If you can, install iotop and watch the processes that cause the I/O.
I tried installing "iotop", but it failed to run because it requires Linux >= 2.6.20. Our CentOS5.2 is 2.6.18-8.
> What we need is more details about your setup, especially
> - checkpoint_segments
> - checkpoint_timeout
> - shared_buffers
# - Memory -
# - Planner Cost Constants -
effective_cache_size = 4GB
# - Checkpoints -
# - Background writer -
bgwriter_delay = 200ms
bgwriter_lru_percent = 1.0
bgwriter_lru_maxpages = 5
bgwriter_all_percent = 0.333
bgwriter_all_maxpages = 5
> also it'd be nice to have samples from the vmstat/iostat and messages from
> the log.
Unfortunately, I don't have "exact" logs when the problem actually happened
|Next Message||Tomas Vondra||2012-03-22 10:43:08||Re: Write workload is causing severe slowdown in Production|
|Previous Message||Tomas Vondra||2012-03-22 10:04:14||Re: Write workload is causing severe slowdown in Production|