Re: [RFC] Should we fix postmaster to avoid slow shutdown?
От | Tsunakawa, Takayuki |
---|---|
Тема | Re: [RFC] Should we fix postmaster to avoid slow shutdown? |
Дата | |
Msg-id | 0A3221C70F24FB45833433255569204D1F65A91B@G01JPEXMBYT05 обсуждение исходный текст |
Ответ на | Re: [RFC] Should we fix postmaster to avoid slow shutdown? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: [RFC] Should we fix postmaster to avoid slow shutdown?
|
Список | pgsql-hackers |
From: pgsql-hackers-owner@postgresql.org > [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Tom Lane > Maybe a workable compromise would be to leave the file present, and have > the stats collector re-write it every (say) five minutes. Then I'd be okay > with having an immediate shutdown skip writing the file; you'd be losing > up to five minutes' worth of activity, but not going completely nuts. So > the stats collector's normal activities would include writing the temp file > on-demand and the permanent file on a timed cycle. > > The other components of the fix (deleting on PITR rewind or stats collector > crash) would remain the same. The manual says: "Also, the collector itself emits a new report at most once per PGSTAT_STAT_INTERVAL milliseconds (500 ms unless alteredwhile building the server). So the displayed information lags behind actual activity." Doesn't this mean that the stats collector writes files in pg_stat_tmp/ every 500ms? If true, how about just moving thosefiles into appropriate locations during recovery, instead of removing the files? I also find others's ideas woth considering -- WAL-logging the stats files, type-specific stats files, etc. -- but I'm afraidthose ideas would only be employed in a new major release, not in released versions. I'm asking for a remedy for auser (and potential users) who use older releases. And, I don't yet understand why patch would make the situation for existingusers, and why stop writing files during immediate/abnormal shutdown requires other efforts. Regards Takayuki Tsunakawa
В списке pgsql-hackers по дате отправления: