Re: how to measure pglogical replication lag

On 26 April 2016 at 03:08, Guo, Yun <YGuo(at)cvent(dot)com> wrote:

> Is there a function or view that could return a measurable replication lag
> of Pglogical ?
>

It's the same as normal streaming replication. Use pg_stat_replication
and/or pg_replication_slots to compare the LSN received by the client to
the current server xlog insert position.

Like streaming replication there's currently no way to find out from the
client side how far behind the client is. I think we should actually change
that by sending an occasional message to the client with the server's
current xlog insert position, though, so the client knows how far behind it
is...

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services