Re: [PATCHES] Infrastructure changes for recovery (v8) - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: [PATCHES] Infrastructure changes for recovery (v8)
Date
Msg-id 1226101491.31701.29.camel@dell.linuxdev.us.dell.com
Whole thread Raw
In response to Infrastructure changes for recovery (v8)  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: [PATCHES] Infrastructure changes for recovery (v8)  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
On Tue, 2008-09-30 at 23:52 +0100, Simon Riggs wrote:
> * optional recovery_safe_start_location parameter now provided in
> recovery.conf, to allow a consistency point to be manually defined if a
> base backup was not taken using standard pg_start/stop backup functions

If using synchronous replication, it seems like this may be useful. For
instance, if the primary server A fails (let's assume power off
failure), then you make the secondary server B the new primary and start
committing transactions, and then you want to bring A back up as a
secondary to B.

Will server A know where to start recovering from, even if many
checkpoints have happened on server B in the meantime? Is there a way to
avoid wiping A and making a new base backup?

Are the safety issues that Heikki brought up potentially solvable, or am
I asking for the impossible?

And also, what if server A is shut down cleanly? Is there any way at all
to get it into recovery mode to catch up with B, or would it require a
new base backup?

I haven't read through the entire thread, so I apologize if this
question has been answered elsewhere.

Regards,Jeff Davis



pgsql-hackers by date:

Previous
From: "David E. Wheeler"
Date:
Subject: Re: [RRR] Tests citext casts
Next
From: Tom Lane
Date:
Subject: Re: [RRR] Tests citext casts