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 > -- PostgreSQL.org Major Contributor Command Prompt, Inc: http://www.commandprompt.com/ - 503.667.4564 Consulting, Training, Support, Custom Development, Engineering