Provide information on the role of a Redis instance in the context of replication, by returning if the instance is currently a
sentinel. The command also returns additional information about the state of the replication (if the role is master or slave) or the list of monitored master names (if the role is sentinel).
The command returns an array of elements. The first element is the role of the instance, as one of the following three strings:
The additional elements of the array depends on the role.
An example of output when ROLE is called in a master instance:
1) "master" 2) (integer) 3129659 3) 1) 1) "127.0.0.1" 2) "9001" 3) "3129242" 2) 1) "127.0.0.1" 2) "9002" 3) "3129543"
The master output is composed of the following parts:
An example of output when ROLE is called in a replica instance:
1) "slave" 2) "127.0.0.1" 3) (integer) 9000 4) "connected" 5) (integer) 3167038
The replica output is composed of the following parts:
slave, because of backward compatbility (see note at the end of this page).
connect(the instance needs to connect to its master),
connecting(the master-replica connection is in progress),
sync(the master and replica are trying to perform the synchronization),
connected(the replica is online).
An example of Sentinel output:
1) "sentinel" 2) 1) "resque-master" 2) "html-fragments-master" 3) "stats-master" 4) "metadata-master"
The sentinel output is composed of the following parts:
Array reply: where the first element is one of
sentinel and the additional elements are role-specific as illustrated above.
1) "master" 2) (integer) 0 3) (empty list or set)
A note about the word slave used in this man page: Starting with Redis 5, if not for backward compatibility, the Redis project no longer uses the word slave. Unfortunately in this command the word slave is part of the protocol, so we'll be able to remove such occurrences only when this API will be naturally deprecated.
© 2009–2018 Salvatore Sanfilippo
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