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ROLE

Syntax​

ROLE

Time complexity: O(1)

Provide information on the role of a Dragonfly instance in the context of replication, by returning if the instance is currently a master or slave. The command also returns additional information about the state of the replication.

Output format​

The command returns an array of elements. The first element is the role of the instance, as one of the following three strings:

  • "master"
  • "slave"

The additional elements of the array depends on the role.

Master output​

An example of output when dragonfly> ROLE is called in a master instance:

1) "master"
2) 1) 1) "127.0.0.1"
      2) "6380"
      3) "stable_sync"

The master output is composed of the following parts:

  1. The string master.
  2. An array composed of a three elements array for each connected replica. Every sub-array contains the replica's IP, port, and replication state. For the state meanings see the replica output description below.

Output of the command on replicas​

An example of output when ROLE is called in a replica instance:

1) "replica"
2) "127.0.0.1"
3) "6379"
4) "stable_sync"

The replica output is composed of the following parts:

  1. The string replica, because of backward compatibility (see note at the end of this page).
  2. The IP of the master.
  3. The port number of the master.
  4. The current replication state, that can be connecting (trying to form a network link), preparation (initial connection has been made), full_sync (the master and replica are performing a full synchronization) and stable_sync (the replica is online)

Return​

Array reply: where the first element is one of master, slave, sentinel and the additional elements are role-specific as illustrated above.