Help Center/ Distributed Cache Service/ User Guide (Kuala Lumpur Region)/ Managing DCS Instances/ Managing Shards and Replicas
Updated on 2024-07-29 GMT+08:00
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Managing Shards and Replicas

This section describes how to query the shards and replicas of a DCS Redis 4.0/5.0 instance and how to manually promote a replica to master.

Currently, this function is supported only by master/standby and cluster DCS Redis 4.0/5.0/6.0 instances. DCS Redis 3.0 instances and single-node DCS Redis 4.0/5.0/6.0 instances do not support this function.

  • A master/standby instance has only one shard with one master and one replica by default. You can view the sharding information on the Shards and Replicas page. To manually switch the master and replica roles, see Performing a Master/Standby Switchover for a DCS Instance.
  • A Redis Cluster instance has multiple shards. Each shard has one master and one replica by default. On the Shards and Replicas page, you can view the sharding information and manually switch the master and replica roles. For details about the number of shards corresponding to different instance specifications, see Redis Cluster.

Promoting a Replica to Master

  1. Log in to the DCS console.
  2. Click in the upper left corner and select a region and a project.
  3. In the navigation pane, choose Cache Manager. The Cache Manager page is displayed.
  1. Click an instance.
  2. Click the Shards and Replicas tab.

    The page displays all shards in the instance and the list of replicas of each shard.

  3. Click to show all replicas of a shard.

    Figure 1 Lists of shards and replicas
    • For a cluster instance, you can promote a replica in a shard to be master.
      1. Click Promote to Master in the row containing another replica which is in the "Replica" role.
      2. Click Yes.
    • Failover Priority can be set for replicas for a master/standby instance.

      Failover priority: If the master fails, the system will be automatically promoted to the replica with the highest priority you specified. If there are multiple replicas sharing the same priority, a selection and switch process will be performed in the internal system. Priority ranges from 0 to 100 in descending order. 0 indicates that the replica will never be automatically promoted, 1 indicates the highest priority, and 100 indicates the lowest priority.

Parent topic: Managing DCS Instances