xref: /redis-3.2.3/sentinel.conf (revision cf737ff1)
1be2be3d9Santirez# Example sentinel.conf
26b5daa2dSantirez
323023fc6Smrb# port <sentinel-port>
423023fc6Smrb# The port that this sentinel instance will run on
523023fc6Smrbport 26379
623023fc6Smrb
7c9437fe5Santirez# sentinel announce-ip <ip>
8c9437fe5Santirez# sentinel announce-port <port>
9c9437fe5Santirez#
10c9437fe5Santirez# The above two configuration directives are useful in environments where,
11c9437fe5Santirez# because of NAT, Sentinel is reachable from outside via a non-local address.
12c9437fe5Santirez#
13c9437fe5Santirez# When announce-ip is provided, the Sentinel will claim the specified IP address
14c9437fe5Santirez# in HELLO messages used to gossip its presence, instead of auto-detecting the
15c9437fe5Santirez# local address as it usually does.
16c9437fe5Santirez#
17c9437fe5Santirez# Similarly when announce-port is provided and is valid and non-zero, Sentinel
18c9437fe5Santirez# will announce the specified TCP port.
19c9437fe5Santirez#
20c9437fe5Santirez# The two options don't need to be used together, if only announce-ip is
21c9437fe5Santirez# provided, the Sentinel will announce the specified IP and the server port
22c9437fe5Santirez# as specified by the "port" option. If only announce-port is provided, the
23c9437fe5Santirez# Sentinel will announce the auto-detected local IP and the specified port.
243d939266SDara Kong#
253d939266SDara Kong# Example:
263d939266SDara Kong#
27c9437fe5Santirez# sentinel announce-ip 1.2.3.4
283d939266SDara Kong
2963d1f9e5Santirez# dir <working-directory>
3063d1f9e5Santirez# Every long running process should have a well-defined working directory.
3163d1f9e5Santirez# For Redis Sentinel to chdir to /tmp at startup is the simplest thing
32*cf737ff1SJan-Erik Rediger# for the process to don't interfere with administrative tasks such as
3363d1f9e5Santirez# unmounting filesystems.
3463d1f9e5Santirezdir /tmp
3563d1f9e5Santirez
36baace5fcSantirez# sentinel monitor <master-name> <ip> <redis-port> <quorum>
37baace5fcSantirez#
386d5fa2e0SYubao Liu# Tells Sentinel to monitor this master, and to consider it in O_DOWN
3923023fc6Smrb# (Objectively Down) state only if at least <quorum> sentinels agree.
406b5daa2dSantirez#
4137b43c8aSantirez# Note that whatever is the ODOWN quorum, a Sentinel will require to
4237b43c8aSantirez# be elected by the majority of the known Sentinels in order to
4337b43c8aSantirez# start a failover, so no failover can be performed in minority.
4437b43c8aSantirez#
4569fa133eSantirez# Slaves are auto-discovered, so you don't need to specify slaves in
4669fa133eSantirez# any way. Sentinel itself will rewrite this configuration file adding
4769fa133eSantirez# the slaves using additional configuration options.
4869fa133eSantirez# Also note that the configuration file is rewritten when a
4969fa133eSantirez# slave is promoted to master.
5069fa133eSantirez#
516b5daa2dSantirez# Note: master name should not include special characters or spaces.
526b5daa2dSantirez# The valid charset is A-z 0-9 and the three characters ".-_".
536b5daa2dSantirezsentinel monitor mymaster 127.0.0.1 6379 2
546b5daa2dSantirez
55db100c46Santirez# sentinel auth-pass <master-name> <password>
56db100c46Santirez#
57db100c46Santirez# Set the password to use to authenticate with the master and slaves.
58db100c46Santirez# Useful if there is a password set in the Redis instances to monitor.
59db100c46Santirez#
60db100c46Santirez# Note that the master password is also used for slaves, so it is not
61db100c46Santirez# possible to set a different password in masters and slaves instances
62db100c46Santirez# if you want to be able to monitor these instances with Sentinel.
63db100c46Santirez#
64db100c46Santirez# However you can have Redis instances without the authentication enabled
65db100c46Santirez# mixed with Redis instances requiring the authentication (as long as the
66db100c46Santirez# password set is the same for all the instances requiring the password) as
67db100c46Santirez# the AUTH command will have no effect in Redis instances with authentication
68db100c46Santirez# switched off.
69db100c46Santirez#
70db100c46Santirez# Example:
71db100c46Santirez#
72db100c46Santirez# sentinel auth-pass mymaster MySUPER--secret-0123passw0rd
73db100c46Santirez
74baace5fcSantirez# sentinel down-after-milliseconds <master-name> <milliseconds>
75baace5fcSantirez#
766b5daa2dSantirez# Number of milliseconds the master (or any attached slave or sentinel) should
776b5daa2dSantirez# be unreachable (as in, not acceptable reply to PING, continuously, for the
786b5daa2dSantirez# specified period) in order to consider it in S_DOWN state (Subjectively
796b5daa2dSantirez# Down).
806b5daa2dSantirez#
816b5daa2dSantirez# Default is 30 seconds.
826b5daa2dSantirezsentinel down-after-milliseconds mymaster 30000
836b5daa2dSantirez
84baace5fcSantirez# sentinel parallel-syncs <master-name> <numslaves>
85baace5fcSantirez#
866b5daa2dSantirez# How many slaves we can reconfigure to point to the new slave simultaneously
876b5daa2dSantirez# during the failover. Use a low number if you use the slaves to serve query
886b5daa2dSantirez# to avoid that all the slaves will be unreachable at about the same
896b5daa2dSantirez# time while performing the synchronization with the master.
906b5daa2dSantirezsentinel parallel-syncs mymaster 1
916b5daa2dSantirez
92baace5fcSantirez# sentinel failover-timeout <master-name> <milliseconds>
93baace5fcSantirez#
9437b43c8aSantirez# Specifies the failover timeout in milliseconds. It is used in many ways:
956b5daa2dSantirez#
9637b43c8aSantirez# - The time needed to re-start a failover after a previous failover was
9737b43c8aSantirez#   already tried against the same master by a given Sentinel, is two
9837b43c8aSantirez#   times the failover timeout.
996b5daa2dSantirez#
10037b43c8aSantirez# - The time needed for a slave replicating to a wrong master according
1016d5fa2e0SYubao Liu#   to a Sentinel current configuration, to be forced to replicate
10237b43c8aSantirez#   with the right master, is exactly the failover timeout (counting since
10337b43c8aSantirez#   the moment a Sentinel detected the misconfiguration).
10437b43c8aSantirez#
10537b43c8aSantirez# - The time needed to cancel a failover that is already in progress but
10637b43c8aSantirez#   did not produced any configuration change (SLAVEOF NO ONE yet not
10737b43c8aSantirez#   acknowledged by the promoted slave).
10837b43c8aSantirez#
10937b43c8aSantirez# - The maximum time a failover in progress waits for all the slaves to be
11037b43c8aSantirez#   reconfigured as slaves of the new master. However even after this time
11137b43c8aSantirez#   the slaves will be reconfigured by the Sentinels anyway, but not with
11237b43c8aSantirez#   the exact parallel-syncs progression as specified.
11337b43c8aSantirez#
11437b43c8aSantirez# Default is 3 minutes.
11537b43c8aSantirezsentinel failover-timeout mymaster 180000
1166b5daa2dSantirez
1179d09ce39Sguiquanz# SCRIPTS EXECUTION
118ed2a691aSantirez#
119ed2a691aSantirez# sentinel notification-script and sentinel reconfig-script are used in order
120ed2a691aSantirez# to configure scripts that are called to notify the system administrator
121ed2a691aSantirez# or to reconfigure clients after a failover. The scripts are executed
122ed2a691aSantirez# with the following rules for error handling:
123ed2a691aSantirez#
1240f259709Santirez# If script exits with "1" the execution is retried later (up to a maximum
125ed2a691aSantirez# number of times currently set to 10).
126ed2a691aSantirez#
1270f259709Santirez# If script exits with "2" (or an higher value) the script execution is
128ed2a691aSantirez# not retried.
129ed2a691aSantirez#
130ed2a691aSantirez# If script terminates because it receives a signal the behavior is the same
131ed2a691aSantirez# as exit code 1.
132ed2a691aSantirez#
133ed2a691aSantirez# A script has a maximum running time of 60 seconds. After this limit is
134ed2a691aSantirez# reached the script is terminated with a SIGKILL and the execution retried.
135ed2a691aSantirez
136ed2a691aSantirez# NOTIFICATION SCRIPT
137ed2a691aSantirez#
138baace5fcSantirez# sentinel notification-script <master-name> <script-path>
139baace5fcSantirez#
1406d5fa2e0SYubao Liu# Call the specified notification script for any sentinel event that is
141baace5fcSantirez# generated in the WARNING level (for instance -sdown, -odown, and so forth).
142baace5fcSantirez# This script should notify the system administrator via email, SMS, or any
143baace5fcSantirez# other messaging system, that there is something wrong with the monitored
144baace5fcSantirez# Redis systems.
145baace5fcSantirez#
146baace5fcSantirez# The script is called with just two arguments: the first is the event type
147baace5fcSantirez# and the second the event description.
148baace5fcSantirez#
14978b606acSJeremy Zawodny# The script must exist and be executable in order for sentinel to start if
150baace5fcSantirez# this option is provided.
151baace5fcSantirez#
152baace5fcSantirez# Example:
153baace5fcSantirez#
154baace5fcSantirez# sentinel notification-script mymaster /var/redis/notify.sh
155baace5fcSantirez
1566275004cSantirez# CLIENTS RECONFIGURATION SCRIPT
1576275004cSantirez#
1586275004cSantirez# sentinel client-reconfig-script <master-name> <script-path>
1596275004cSantirez#
16037b43c8aSantirez# When the master changed because of a failover a script can be called in
1616275004cSantirez# order to perform application-specific tasks to notify the clients that the
1626275004cSantirez# configuration has changed and the master is at a different address.
1636275004cSantirez#
1646275004cSantirez# The following arguments are passed to the script:
1656275004cSantirez#
1666275004cSantirez# <master-name> <role> <state> <from-ip> <from-port> <to-ip> <to-port>
1676275004cSantirez#
16837b43c8aSantirez# <state> is currently always "failover"
1696275004cSantirez# <role> is either "leader" or "observer"
1706275004cSantirez#
1716275004cSantirez# The arguments from-ip, from-port, to-ip, to-port are used to communicate
1726275004cSantirez# the old address of the master and the new address of the elected slave
17337b43c8aSantirez# (now a master).
1746275004cSantirez#
1756275004cSantirez# This script should be resistant to multiple invocations.
1766275004cSantirez#
1776275004cSantirez# Example:
1786275004cSantirez#
1796275004cSantirez# sentinel client-reconfig-script mymaster /var/redis/reconfig.sh
1806275004cSantirez
181baace5fcSantirez
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