Re: wal-size limited to 16MB - Performance issue for subsequent backup

> On 2014-10-20 21:03:59 +0200, jesper@krogh.cc wrote:
>> One of our "production issues" is that the system generates lots of
>> wal-files, lots is like 151952 files over the last 24h, which is about
>> 2.4TB worth of WAL files. I wouldn't say that isn't an issue by itself,
>> but the system does indeed work fine. We do subsequently gzip the files
>> to
>> limit actual disk-usage, this makes the files roughly 30-50% in size.
>
> Have you analyzed what the source of that volume is? Which version of
> postgres are you using? What's your checkpoint_timeout/segments
> settings?

Suggestions are surely welcome. I do suspect the majority is from 30
concurrent processes updating an 506GB GIN index, but it would be nice to
confirm that. There is also a message-queue in the DB with a fairly high
turnaround.

Currently PG 9.2 moving to 9.3 hopefully before end-of-year,
checkpoint_timeout = 30min, checkpoint_segments = 4096.

According to logs checkpoints are roughly 15 minutes apart.

Jesper