mysql-flush.sh.sample (1774B)
1 #!/bin/sh 2 3 # Flush MySQL tables to the disk before the filesystem is frozen. 4 # At the same time, this keeps a read lock in order to avoid write accesses 5 # from the other clients until the filesystem is thawed. 6 7 MYSQL="/usr/bin/mysql" 8 MYSQL_OPTS="-uroot" #"-prootpassword" 9 FIFO=/var/run/mysql-flush.fifo 10 11 # Check mysql is installed and the server running 12 [ -x "$MYSQL" ] && "$MYSQL" $MYSQL_OPTS < /dev/null || exit 0 13 14 flush_and_wait() { 15 printf "FLUSH TABLES WITH READ LOCK \\G\n" 16 trap 'printf "$(date): $0 is killed\n">&2' HUP INT QUIT ALRM TERM 17 read < $FIFO 18 printf "UNLOCK TABLES \\G\n" 19 rm -f $FIFO 20 } 21 22 case "$1" in 23 freeze) 24 mkfifo $FIFO || exit 1 25 flush_and_wait | "$MYSQL" $MYSQL_OPTS & 26 # wait until every block is flushed 27 while [ "$(echo 'SHOW STATUS LIKE "Key_blocks_not_flushed"' |\ 28 "$MYSQL" $MYSQL_OPTS | tail -1 | cut -f 2)" -gt 0 ]; do 29 sleep 1 30 done 31 # for InnoDB, wait until every log is flushed 32 INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX) 33 [ $? -ne 0 ] && exit 2 34 trap "rm -f $INNODB_STATUS; exit 1" HUP INT QUIT ALRM TERM 35 while :; do 36 printf "SHOW ENGINE INNODB STATUS \\G" |\ 37 "$MYSQL" $MYSQL_OPTS > $INNODB_STATUS 38 LOG_CURRENT=$(grep 'Log sequence number' $INNODB_STATUS |\ 39 tr -s ' ' | cut -d' ' -f4) 40 LOG_FLUSHED=$(grep 'Log flushed up to' $INNODB_STATUS |\ 41 tr -s ' ' | cut -d' ' -f5) 42 [ "$LOG_CURRENT" = "$LOG_FLUSHED" ] && break 43 sleep 1 44 done 45 rm -f $INNODB_STATUS 46 ;; 47 48 thaw) 49 [ ! -p $FIFO ] && exit 1 50 echo > $FIFO 51 ;; 52 53 *) 54 exit 1 55 ;; 56 esac