Re: WAL restore is very slow

First off, why are you still running on a rather small r5 instance? AWS has had r6 instances available for some time, and they’re faster and more efficient. Of my some 30 instances which I take care of, I haven’t had any r5’s in quite some time.

And it sounds here that you’re running on an EC2 instance as well. Is there some reason you haven’t gone to RDS? Cluster configuration in RDS uses an internal RDS specific replication method that does not involve WAL files.
—
John

Sent from my iPad

> On Aug 29, 2022, at 6:10 AM, Madhu Sudan <madhusudan0429(at)gmail(dot)com> wrote:
>
> 
> Hi
>
> We have PG-14 with a huge data set of 14 TB running on r5b.2xlarge. We have set up WAL archiving and restoring them onto a replica server. The WAL restore on the replica is very slow and we are not able to achieve the 4 hour delayed replica. It is always behind 30 hrs with the huge WAL generation.
>
> I have checked the following and they look fine
> 1. Bottlenecks on the replica server
> 2. Memory consumption and swap
> 3. EFS IO throughput
> 4.checkpoint_completion_target = 0.9
> 5. wal_buffers = 16MB
> 6. wal_log_hints = on
> 7. Verified logs and didn't find anything useful related to the issue
>
> Can you please suggest how to improve the WAL restore performance
>
> Thank you
> Madhu Sudan
>
>
>