>>> Questions: >>> >>> A. Why does the replica need 00000002.history? Shouldn't it only need >>> 00000003.history? >> >> From where is the base backup taken in case of the node started at 5?
It is the same backup used to restore the master, restored to a point in time 5 minutes earlier just to make sure the replica isn't ahead of the master. > > The related source code comment says > > /* > * Get any missing history files. We do this always, even when we're > * not interested in that timeline, so that if we're promoted to > * become the master later on, we don't select the same timeline that > * was already used in the current master. This isn't bullet-proof - > * you'll need some external software to manage your cluster if you > * need to ensure that a unique timeline id is chosen in every case, > * but let's avoid the confusion of timeline id collisions where we > * can. > */ > WalRcvFetchTimeLineHistoryFiles(startpointTLI, primaryTLI); So this seems to be something we're doing "just in case" which is preventing a useful way to spin up large master/replica clusters from PITR backup. Might this be something we want to change, and simply error that we can't find the history file instead of FATAL? -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
