Re: [HACKERS] An attempt to reduce WALWriteLock contention - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [HACKERS] An attempt to reduce WALWriteLock contention
Date
Msg-id CAA4eK1LRWXT57wWMrFHvL3S_12LfNeb3kaRxG19X3vyktJhzOw@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] An attempt to reduce WALWriteLock contention  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Thu, Jun 22, 2017 at 6:54 AM, Andres Freund <andres@anarazel.de> wrote:
> On 2017-06-21 00:57:32 -0700, jasrajd wrote:
>> We are also seeing contention on the walwritelock and repeated writes to the
>> same offset if we move the flush outside the lock in the Azure environment.
>> pgbench doesn't scale beyond ~8 cores without saturating the IOPs or
>> bandwidth. Is there more work being done in this area?
>

That should not happen if the writes from various backends are
combined in some way.  However, it is not very clear what exactly you
have done as part of taking flush calls out of walwritelock.  Can you
share patch or some details about how you have done it and how have
you measured the contention you are seeing?



-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [HACKERS] Logical replication: stuck spinlock at ReplicationSlotRelease
Next
From: Amit Kapila
Date:
Subject: Re: [HACKERS] Broken hint bits (freeze)