Re: Summary and Plan for Hot Standby - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Summary and Plan for Hot Standby
Date
Msg-id 4B00151B.8070807@enterprisedb.com
Whole thread Raw
In response to Re: Summary and Plan for Hot Standby  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Summary and Plan for Hot Standby
Re: Summary and Plan for Hot Standby
List pgsql-hackers
Simon Riggs wrote:
> On Sun, 2009-11-15 at 16:07 +0200, Heikki Linnakangas wrote:
>> - If WAL recovery runs out of lock space while acquiring an
>> AccessExclusiveLock on behalf of a transaction that ran in the master,
>> it will FATAL and abort recovery, bringing down the standby. Seems like
>> it should wait/cancel queries instead.
> 
> Hard resources will always be an issue. If the standby has less than it
> needs, then there will be problems. All of those can be corrected by
> increasing the resources on the standby and restarting. This effects
> max_connections, max_prepared_transactions, max_locks_per_transaction,
> as documented.

There's no safe setting for those that would let you avoid the issue. No
matter how high you set them, it will be possible for read-only backends
to consume all the lock space, causing recovery to abort and bring down
the standby.

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


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