Re: [streaming replication] 9.1.3 streaming replication bug ?

On Wed, Apr 11, 2012 at 10:06 AM, 乔志强 <qiaozhiqiang(at)leadcoretech(dot)com> wrote:
> synchronous_commit is not set, default is "on" ?
> #synchronous_commit = on                # synchronization level; on, off, or local

Yes.

>>Otherwise the master might be filled up with lots of unsent WAL files and which might cause PANIC error in the master, when there is no standby.
>>IOW, the master tries to avoid a PANIC error rather than termination of replication.
>
> Can we have a config option for keep unsent WAL file for replication ?

No. We discussed about such feature before, but it had failed to be committed.
I think it's useful, so I hope it'll be usable in the future release.

> How can I do when I need a backup standby server and
>    wal_keep_segments = 3 for save master disk usage(master will delete wal before send to standby now when heavy load, Need modify some config?)

Yes, increase wal_keep_segments. Even if you set wal_keep_segments to 64,
the amount of disk space for WAL files is only 1GB, so there is no need to worry
so much, I think. No?

> #checkpoint_segments = 3                # in logfile segments, min 1, 16MB each

Increase checkpoint_segments. In this setting, I guess checkpoints run too
frequently in heavy load, and WAL files are removed too aggressively.

Regards,

--
Fujii Masao