Re: streaming replication breaks horribly if master crashes

Joshua D. Drake <jd@commandprompt.com>

From: "Joshua D. Drake" <jd@commandprompt.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-06-16T19:53:09Z
Lists: pgsql-hackers
On Wed, 2010-06-16 at 15:47 -0400, Robert Haas wrote:

> So, obviously at this point my slave database is corrupted beyond
> repair due to nothing more than an unexpected crash on the master.
> That's bad.  What is worse is that the system only detected the
> corruption because the slave had crossed an xlog segment boundary
> which the master had not crossed.  Had it been otherwise, when the
> slave rewound to the beginning of the current segment, it would have
> had no trouble getting back in sync with the master - but it would
> have done this after having replayed WAL that, from the master's point
> of view, doesn't exist.  In other words, the database on the slave
> would be silently corrupted.
> 
> I don't know what to do about this, but I'm pretty sure we can't ship it as-is.

The slave must be able to survive a master crash.

Joshua D. Drake


> 
> -- 
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise Postgres Company
> 

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