Pavel Ivanov <[email protected]> writes: > Sorry, I didn't quite understand.
Sorry for being unclear, let me elaborate: > You didn't mention <log-bin>.state here. Is it intentional? Does it > try to look into <log-bin>.state after rpl_slave_state and binlogs? Or > e.g. in the situation when binlogs are not found? There is just a single binlog state. The binlog state consists of the last GTID logged into the binlog for every (domain_id, server_id) pair. It also remembers the most recent GTID per domain. During normal server operation, the binlog state is kept only in-memory. The binlog state can be recovered from the binlog simply by scanning and recording every GTID encountered on the way. We do this after a crash. However, as an optimisation, to avoid having to scan binlog files at normal startup, we write out the binlog state to <log-bin>.state at server shutdown and read it back in at server startup. This is the only use of the file <log-bin>.state. >> <log-bin>.state contains the current binlog state at the time of >> shutdown. This is used to be able to output the correct Gtid_list event at >> the >> start of the new binlog created at server startup, and also to initialise the >> sequence number counter for new events. > > Again it "used to be" which means it's not used to do that anymore? Just bad wording on my part, I meant "it is used", not that "it used to be". So to clarify: The server maintains an in-memory struct rpl_binlog_state with last GTIDs binlogged per-domain and per-(domain_id,server_id). At server shutdown, this in-memory state is saved to <log-bin>.state. At server startup, if we detect that binlog was properly closed and we do not need to do crash recovery, the in-memory struct rpl_binlog_state is initialised from the file <log-bin>.state. If we detect that we crashed prior and need to do crash recovery, <log-bin>.state is not consulted. Instead the in-memory struct rpl_binlog_state is initialised during the scan of the binlog, as part of crash recovery. I hope this makes things clear, - Kristian. _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
