Re: [GENERAL] Manage slot in logical/pglogical replication - Mailing list pgsql-general

From Alvaro Herrera
Subject Re: [GENERAL] Manage slot in logical/pglogical replication
Date
Msg-id 20170713155531.hfzfxdvibw46bn6x@alvherre.pgsql
Whole thread Raw
In response to [GENERAL] Manage slot in logical/pglogical replication  (dpat <denni.pat@gmail.com>)
Responses Re: [GENERAL] Manage slot in logical/pglogical replication  (dpat <denni.pat@gmail.com>)
List pgsql-general
dpat wrote:

> i have configure a master-replica replication with new pglogical 2.0.
> I have to replicate data over MPLS/VPN, so there is a possibility that the
> link temporarily interrupts.
> I know that you have to be accurately estimated pg_xlog folder.
> How can I handle the prolonged interruption of the link?
> Can I just extend the folder? Or drop the slot?

Yeah, data accumulates in the origin side ("master"), so you need to
make sure you have sufficient room in pg_xlog to hold all the data
generated during the network interruption.

Dropping the slot would of course release the disk space, but it would
mean that you'd have to re-create the replica afterwards.  I suppose you
could have pg_xlog large enough to hold as much data as possible for a
mid-sized network interruption, and drop the slot as a last resource if
a connection interrupts for long enough that you risk causing
reliability problems in the origin.

> I can create a consumer who temporarily saves the data in an external file?

I don't think so.

--
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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