Re: wal_sender_delay is still required?

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2011-02-26T21:12:59Z
Lists: pgsql-hackers
On 07.12.2010 05:51, Fujii Masao wrote:
> On Tue, Dec 7, 2010 at 12:22 PM, Robert Haas<robertmhaas@gmail.com>  wrote:
>>> Fair enough. How about increasing the default to 10 seconds?
>>> Since bgwriter has already using 10s as a nap time if there is no
>>> configured activity, I think that 10s is non-nonsense default value.
>>
>> What do we get out of making this non-configurable?
>
> Which would make the setting of replication simpler, I think.
> But I agree to just increase the default value of wal_sender_delay
> rather than dropping it.

I dropped the ball on this one..

For comparison, the archiver process and autovacuum launcher wake up 
once a second to check if postmaster is still alive. bgwriter, when 
bgwriter_lru_maxpages and archive_timeout are set to 0 to disable it, 
checks for dead postmaster every 10 seconds.

I'll bump the default for wal_sender_delay to 1 second. Maybe an even 
higher value would be good, but it also seems good to kill replication 
connections in a timely fashion if postmaster dies.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com