Re: Synchronous Log Shipping Replication - Mailing list pgsql-hackers

From Dimitri Fontaine
Subject Re: Synchronous Log Shipping Replication
Date
Msg-id 200809091532.45364.dfontaine@hi-media.com
Whole thread Raw
In response to Re: Synchronous Log Shipping Replication  (Markus Wanner <markus@bluegap.ch>)
Responses Re: Synchronous Log Shipping Replication  (Simon Riggs <simon@2ndQuadrant.com>)
Re: Synchronous Log Shipping Replication  (Markus Wanner <markus@bluegap.ch>)
List pgsql-hackers
Le mardi 09 septembre 2008, Markus Wanner a écrit :
> ..and it will still has to wait until WAL is written to disk on the
> local node, as we do now. These are two different things to wait for.
> One is a network socket operation, the other is an fsync(). As these
> don't work together too well (blocking), you better run that in two
> different processes.

Exactly the point. The process is now already waiting in all cases, so maybe
we could just force waiting some WALSender signal before sending the fsync()
order, so we now have Group Commit.
I'm not sure this is a good idea at all, it's just the way I understand how
adding WALSender process in the mix could give Group Commit feature for free.

Regards,
--
dim

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