-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 05/31/2013 10:46 AM, Heikki Linnakangas wrote: > On 31.05.2013 20:38, Joe Conway wrote: >> I can check for the presence of $PGDATA/backup_label in order to >> detect a backup in progress (i.e. pg_start_backup() has been run >> and pg_stop_backup() has not yet been run). >> >> However there is a period of time after pg_start_backup() is >> first executed to when it completes, during which backup_label >> file does not exist yet, but the backup has essentially been >> started. Is there any way to detect this state? > > What are you trying to accomplish? Even if you eliminate that > window, it's always possible that a backup starts just after you've > checked that there is no backup in progress.
We can lay down a lockfile before checking for backup in progress, and the script that starts the backup can check for the lockfile before doing anything. There is still a race-window, but I want to minimize it. pg_is_in_backup() mentioned nearby on this thread will help close the gap. Joe - -- Joe Conway credativ LLC: http://www.credativ.us Linux, PostgreSQL, and general Open Source Training, Service, Consulting, & 24x7 Support -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJRqO7WAAoJEDfy90M199hlSPkP/AtbQjRImH0TYp0nGV+XG8zq zyeaQXtU1kB+eon7egUjObN/khnM2ePlqmKBG5TuZW8HQWK+AnISG68rB/FU10Vo rgiN2BSw/GZ4oCsJ1tXnbvyE70vRhq5pMbEbkfCCqjt/LZOGg50/Z/ROmr7RwmSx 2dSVsvhUryYS3eo/OxgkyBlCtnlV3fkkdKLc6S5VCaNWfHvu731Q9JPgN6/S7NhB kcpjdD8/OA6m7MH7VkZkYcz1clVJKDCTRP39MteM4RT4IHZL6+rztnqrgICEccSh b+gP8GUipY4o/V3QBTH09OXkSjyomgobtRFUqtB5DslY3JCdATyZdDKePUyHqZdo /jVeUddde22BkRIoC98QwB1MiNUNXXrHBZqUV9ITlj1BrFC0HpWXJ4d/TP6Sah7W 4+n6eW+2mbRd3w+TzY95Q4i3gT3U4DS6qJKL36DBlKJQhwlmvJjZS1AMEXoaAiMj BBl78u9Bo6meKxKacrwXq9vfgkKwup/kc8vHwEHvJz+nM/j2/Gve0iwjhIuuXoHp XETld9x2LWiEN8xYzI5halycP1eR7eD/IBDm8X6FzUCL+gV3/ORvYxwAR587aprf eS143/GS1JPH9nt+3ILhCGrwaBz8a/HPWE3eYnJqYlH8hVmoxjbZToDjU3FHdCNg zsdcwv1Lg7XtX6wCMiEm =eG9/ -----END PGP SIGNATURE----- -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
