Re: Streaming Replication Networking Best Practices?

[Don Seiler <don@xxxxxxxxx>]

On Mon, May 14, 2018 at 11:17 AM, Flavio Henrique Araque Gurgel <fhagur@xxxxxxxxx> wrote:

If you're running 9.6, you can use replication slots to avoid to mess with wal_keep_segments [1]

I don't think replication slots would help here. As I mentioned in my original post, I changed wal_keep_files so that the WAL files weren't deleted too soon, but the streaming was still slow and lagged even further behind. My understanding is replication slots just serve to keep the WAL files in place. If I did that then they'd probably fill up the primary disk since the DR replica would take too long to process them all.

 

Be aware that not only network bandwidth and latency are responsable for that behaviour, wal_receiver, disk write capability on your standby can be bottlenecks too.

It happens to me in local networks with 10Gbps capable hardware.

Worth looking into. I would have assumed that since our local replica handles the storage I/O just fine that the replica would since they use the same model of hardware for server and storage array. I'll make sure that my assumptions are correct though and see if anything else is up there.

Thanks!

Don.

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Don Seiler
www.seiler.us