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#!/bin/sh
# ########################################################################
# This program is part of $PROJECT_NAME$
# License: GPL License (see COPYING)
# Authors:
# Baron Schwartz, Roman Vynar
# ########################################################################
# ########################################################################
# Redirect STDERR to STDOUT; Nagios doesn't handle STDERR.
# ########################################################################
exec 2>&1
# ########################################################################
# Set up constants, etc.
# ########################################################################
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
STATE_DEPENDENT=4
# ########################################################################
# Run the program.
# ########################################################################
main() {
# Get options
OPT_ENSURE_SBM=0
MIN_DELAY_SET=0
for o; do
case "${o}" in
-c) shift; OPT_CRIT="${1}"; shift; ;;
--defaults-file) shift; OPT_DEFT="${1}"; shift; ;;
-H) shift; OPT_HOST="${1}"; shift; ;;
-l) shift; OPT_USER="${1}"; shift; ;;
-L) shift; OPT_LOPA="${1}"; shift; ;;
-m) shift; OPT_MIN="${1}"; MIN_DELAY_SET=1; shift; ;;
-p) shift; OPT_PASS="${1}"; shift; ;;
-P) shift; OPT_PORT="${1}"; shift; ;;
-S) shift; OPT_SOCK="${1}"; shift; ;;
-s) shift; OPT_SRVID="${1}"; shift; ;;
-T) shift; OPT_TABLE="${1}"; shift; ;;
-u) shift; OPT_UTC=1; ;;
-w) shift; OPT_WARN="${1}"; shift; ;;
--master-conn) shift; OPT_MASTERCONN="${1}"; shift; ;;
--channel) shift; OPT_CHANNEL="${1}"; shift; ;;
--unconfigured) shift; OPT_REPLNOTSET=1; ;;
--ensure-sbm) shift; OPT_ENSURE_SBM=1; ;;
--version) grep -A2 '^=head1 VERSION' "$0" | tail -n1; exit 0 ;;
--help) perl -00 -ne 'm/^ Usage:/ && print' "$0"; exit 0 ;;
-*) echo "Unknown option ${o}. Try --help."; exit 1; ;;
esac
done
OPT_WARN=${OPT_WARN:-300}
OPT_CRIT=${OPT_CRIT:-600}
OPT_MIN=${OPT_MIN:-0}
if [ -e '/etc/nagios/mysql.cnf' ]; then
OPT_DEFT="${OPT_DEFT:-/etc/nagios/mysql.cnf}"
fi
if is_not_sourced; then
if [ -n "$1" ]; then
echo "WARN spurious command-line options: $@"
exit 1
fi
fi
# Get replication delay from a heartbeat table or from SHOW SLAVE STATUS.
get_slave_status $1
if [ "${OPT_TABLE}" ]; then
if [ -z "${OPT_UTC}" ]; then
NOW_FUNC='UNIX_TIMESTAMP()'
else
NOW_FUNC='UNIX_TIMESTAMP(UTC_TIMESTAMP)'
fi
if [ "${OPT_SRVID}" == "MASTER" ]; then
if [ "${MYSQL_CONN}" = 0 ]; then
OPT_SRVID=$(awk '/Master_Server_Id/{print $2}' "${TEMP_SLAVEDATA}")
fi
fi
SQL="SELECT MAX(${NOW_FUNC} - ROUND(UNIX_TIMESTAMP(ts))) AS delay
FROM ${OPT_TABLE} WHERE (${OPT_SRVID:-0} = 0 OR server_id = ${OPT_SRVID:-0})"
LEVEL=$(mysql_exec "${SQL}")
MYSQL_CONN=$?
else
if [ "${MYSQL_CONN}" = 0 ]; then
LEVEL=$(awk '/Seconds_Behind_Master/{print $2}' "${TEMP_SLAVEDATA}")
fi
fi
# Check for SQL thread errors
LAST_SLAVE_ERRNO=$(awk '/Last_SQL_Errno/{print $2}' "${TEMP_SLAVEDATA}")
# Build the common perf data output for graph trending
PERFDATA="replication_delay=${LEVEL:-0};${OPT_WARN};${OPT_CRIT};0;"
# Test whether the delay is too long.
if [ "$MYSQL_CONN" = 0 ]; then
NOTE="${LEVEL:-0} seconds of replication delay"
if [ "${LEVEL:-""}" = "NULL" ]; then
test ${MIN_DELAY_SET} -eq 1 && \
test ${LAST_SLAVE_ERRNO} -eq 0 && \
test ${OPT_ENSURE_SBM} -eq 0 && \
NOTE="OK NULL seconds of replication delay" || NOTE="UNK replica is stopped"
elif [ -z "${LEVEL}" -a "${OPT_REPLNOTSET}" ]; then
NOTE="UNK This server is not configured as a replica."
# pt-slave-delayed slave
elif [ ${MIN_DELAY_SET} -eq 1 ] && [ "${LEVEL:-0}" -lt "${OPT_MIN}" ]; then
NOTE="CRIT (delayed slave) $NOTE | $PERFDATA"
elif [ "${LEVEL:-0}" -gt "${OPT_CRIT}" ]; then
NOTE="CRIT $NOTE | $PERFDATA"
elif [ "${LEVEL:-0}" -gt "${OPT_WARN}" ]; then
NOTE="WARN $NOTE | $PERFDATA"
else
NOTE="OK $NOTE | $PERFDATA"
fi
else
NOTE="UNK could not determine replication delay"
fi
echo $NOTE
}
# ########################################################################
# Execute a MySQL command.
# ########################################################################
mysql_exec() {
mysql ${OPT_DEFT:+--defaults-file="${OPT_DEFT}"} \
${OPT_LOPA:+--login-path="${OPT_LOPA}"} \
${OPT_HOST:+-h"${OPT_HOST}"} ${OPT_PORT:+-P"${OPT_PORT}"} \
${OPT_USER:+-u"${OPT_USER}"} ${OPT_PASS:+-p"${OPT_PASS}"} \
${OPT_SOCK:+-S"${OPT_SOCK}"} -ss -e "$1"
}
# ########################################################################
# Determine whether this program is being executed directly, or sourced/included
# from another file.
# ########################################################################
is_not_sourced() {
[ "${0##*/}" = "pmp-check-mysql-replication-delay" ] || [ "${0##*/}" = "bash" -a "$_" = "$0" ]
}
# ########################################################################
# Captures the "SHOW SLAVE STATUS" output into a temp file.
# ########################################################################
get_slave_status() {
TEMP_SLAVEDATA=$(mktemp -t "${0##*/}.XXXXXX") || exit $?
trap "rm -f '${TEMP_SLAVEDATA}' >/dev/null 2>&1" EXIT
if [ -z "$1" ]; then
if [ "${OPT_MASTERCONN}" ]; then
# MariaDB multi-source replication
mysql_exec "SHOW SLAVE '${OPT_MASTERCONN}' STATUS\G" > "${TEMP_SLAVEDATA}"
elif [ "${OPT_CHANNEL}" ]; then
mysql_exec "SHOW SLAVE STATUS FOR CHANNEL '${OPT_CHANNEL}'\G" > "${TEMP_SLAVEDATA}"
else
# Leverage lock-free SHOW SLAVE STATUS if available
mysql_exec "SHOW SLAVE STATUS NONBLOCKING\G" > "${TEMP_SLAVEDATA}" 2>/dev/null ||
mysql_exec "SHOW SLAVE STATUS NOLOCK\G" > "${TEMP_SLAVEDATA}" 2>/dev/null ||
mysql_exec "SHOW SLAVE STATUS\G" > "${TEMP_SLAVEDATA}"
fi
MYSQL_CONN=$?
else
# This is for testing only.
cat "$1" > "${TEMP_SLAVEDATA}" 2>/dev/null
MYSQL_CONN=0
fi
}
# ########################################################################
# Execute the program if it was not included from another file.
# This makes it possible to include without executing, and thus test.
# ########################################################################
if is_not_sourced; then
OUTPUT=$(main "$@")
EXITSTATUS=$STATE_UNKNOWN
case "${OUTPUT}" in
UNK*) EXITSTATUS=$STATE_UNKNOWN; ;;
OK*) EXITSTATUS=$STATE_OK; ;;
WARN*) EXITSTATUS=$STATE_WARNING; ;;
CRIT*) EXITSTATUS=$STATE_CRITICAL; ;;
esac
echo "${OUTPUT}"
exit $EXITSTATUS
fi
# ############################################################################
# Documentation
# ############################################################################
: <<'DOCUMENTATION'
=pod
=head1 NAME
pmp-check-mysql-replication-delay - Alert when MySQL replication becomes delayed.
=head1 SYNOPSIS
Usage: pmp-check-mysql-replication-delay [OPTIONS]
Options:
-c CRIT Critical threshold; default 600.
--defaults-file FILE Only read mysql options from the given file.
Defaults to /etc/nagios/mysql.cnf if it exists.
-H HOST MySQL hostname.
-l USER MySQL username.
-L LOGIN-PATH Use login-path to access MySQL (with MySQL client 5.6).
-m CRIT Minimal threshold to ensure for delayed slaves; default 0.
-p PASS MySQL password.
-P PORT MySQL port.
-S SOCKET MySQL socket file.
-s SERVERID MySQL server ID of master, if using pt-heartbeat table. If
the parameter is set to "MASTER" the plugin will lookup the
server_id of the master
-T TABLE Heartbeat table used by pt-heartbeat.
-u Use UTC time to count the delay in case pt-heartbeat is run
with --utc option.
-w WARN Warning threshold; default 300.
--master-conn NAME Master connection name for MariaDB multi-source replication.
--channel NAME Master channel name for multi-source replication (MySQL 5.7.6+).
--unconfigured Alert when replica is not configured at all; default no.
--ensure-sbm Disallow Seconds_Behind_Master to be NULL for delayed slaves when -m is used
--help Print help and exit.
--version Print version and exit.
Options must be given as --option value, not --option=value or -Ovalue.
Use perldoc to read embedded documentation with more details.
=head1 DESCRIPTION
This Nagios plugin examines whether MySQL replication is delayed too much. By
default it uses SHOW SLAVE STATUS, but the output of the Seconds_behind_master
column from this command is unreliable, so it is better to use pt-heartbeat from
Percona Toolkit instead. Use the -T option to specify which table pt-heartbeat
updates. Use the -s option to specify the master's server_id to compare
against; otherwise the plugin reports the maximum delay from any server. Use
the -s options with the value "MASTER" to have plugin lookup the master's server_id
If you want to run this check against the delayed slaves, e.g. those running
with pt-slave-delay tool, you may want to use -m option specifying the minimal
delay that should be ongoing, otherwise the plugin will alert critical.
=head1 PRIVILEGES
This plugin executes the following commands against MySQL:
=over
=item *
C<SHOW SLAVE STATUS [NONBLOCKING|NOLOCK]>
or
=item *
C<SELECT> from the C<pt-heartbeat> table.
=back
This plugin executes no UNIX commands that may need special privileges.
=head1 COPYRIGHT, LICENSE, AND WARRANTY
This program is copyright 2012-$CURRENT_YEAR$ Baron Schwartz, 2012-$CURRENT_YEAR$ Percona Inc.
Feedback and improvements are welcome.
THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2. You should have received a copy of the GNU General
Public License along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
=head1 VERSION
$PROJECT_NAME$ pmp-check-mysql-replication-delay $VERSION$
=cut
DOCUMENTATION
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