maybe that's a systemd thing i know Fedora 19 has not a recent systemd but the question remains if systemctl in case of "Type=simple" may act the same way while stop a service as for starting - send the SIGTERM and immediately return while the binary still writes data
that could explain race conditions like below * stop mysqld instance 1 * stop mysqld instance 2 * the services still flush data but "systemctl" already returned * rsync both datadir * corruption -------- Original-Nachricht -------- Betreff: race conditions after SIGTERM Datum: Thu, 24 Jul 2014 12:42:51 +0200 Von: Reindl Harald <h.rei...@thelounge.net> An: Mailing-List mariadb <"maria-discuss"@lists.launchpad.net> how can that script lead to a race condition where files are not fully written to disk? that never happens if the systemd-unit for the replication instance has "ExecStopPost=/usr/bin/sleep 1" and waits a while my only explaination is that mysqld returns after the SIGTERM from systemd before all data are completly written in some racy situations and so rsynced incompletly to the datadir of the other instance _________________________________________________________ #!/bin/bash systemctl stop replication.service systemctl stop mysqld.service rsync $RSYNC_PARAMS /mysql_replication/ /mysql_data/ systemctl start replication.service systemctl start mysqld.service _________________________________________________________ [Unit] Description=MariaDB Replication [Service] Type=simple PIDFile=/run/mysqld/mysqld_replication.pid ExecStart=/usr/libexec/mysqld --defaults-file=/etc/my-replication.cnf --pid-file=/run/mysqld/mysqld_replication.pid --socket=/var/lib/mysql/mysql_replication.sock --open-files-limit=30000 --basedir=/usr --user=mysql Environment="LANG=en_GB.UTF-8" Restart=always RestartSec=1 _________________________________________________________ 140724 12:22:59 [Note] /usr/libexec/mysqld: Shutdown complete 140724 12:23:01 [Note] Plugin 'InnoDB' is disabled. Cannot find checkpoint record at LSN (1,0x35767) 140724 12:23:01 [ERROR] mysqld: Aria recovery failed. Please run aria_chk -r on all Aria tables and delete all aria_log.######## files 140724 12:23:01 [ERROR] Plugin 'Aria' init function returned error. 140724 12:23:01 [ERROR] Plugin 'Aria' registration as a STORAGE ENGINE failed. 140724 12:23:01 [Note] Plugin 'FEDERATED' is disabled. 140724 12:23:01 [Note] Plugin 'FEEDBACK' is disabled. 140724 12:23:01 [ERROR] Aria engine is not enabled or did not start. The Aria engine must be enabled to continue as mysqld was configured with --with-aria-tmp-tables 140724 12:23:01 [ERROR] Aborting 140724 12:23:01 [Note] /usr/libexec/mysqld: Shutdown complete 140724 12:23:03 [Note] Plugin 'InnoDB' is disabled. Cannot find checkpoint record at LSN (1,0x35767)
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