Adding a read replica for Redis OSS (Cluster Mode Disabled)
Information in the following topic applies to Redis OSS (cluster mode disabled) replication groups only.
As your read traffic increases, you might want to spread those reads across more nodes and reduce the read pressure on any one node. In this topic, you can find how to add a read replica to a Redis OSS (cluster mode disabled) cluster.
A Redis OSS (cluster mode disabled) replication group can have a maximum of five read replicas. If you attempt to add a read replica to a replication group that already has five read replicas, the operation fails.
For information about adding replicas to a Redis OSS (cluster mode enabled) replication group, see the following:
You can add a read replica to a Redis OSS (cluster mode disabled) cluster using the ElastiCache Console, the AWS CLI, or the ElastiCache API.
Related topics
Adding a read replica to a replication group (AWS CLI)
To add a read replica to a Redis OSS (cluster mode disabled) replication group,
use the AWS CLI create-cache-cluster
command,
with the parameter --replication-group-id
to specify
which replication group to add the cluster (node) to.
The following example creates the cluster my-read replica
and adds it
to the replication group my-replication-group
. The node types, parameter
groups, security groups, maintenance window, and other settings for the read replica
are the same as for the other nodes in my-replication-group
.
For Linux, macOS, or Unix:
aws elasticache create-cache-cluster \ --cache-cluster-id
my-read-replica
\ --replication-group-idmy-replication-group
For Windows:
aws elasticache create-cache-cluster ^ --cache-cluster-id
my-read-replica
^ --replication-group-idmy-replication-group
For more information on adding a read replica using the CLI, see create-cache-cluster in the Amazon ElastiCache Command Line Reference.
Adding a read replica to a replication group using the API
To add a read replica to a Redis OSS (cluster mode disabled) replication group,
use the ElastiCache CreateCacheCluster
operation,
with the parameter ReplicationGroupId
to specify
which replication group to add the cluster (node) to.
The following example creates the cluster myReadReplica
and adds it
to the replication group myReplicationGroup
. The node types, parameter
groups, security groups, maintenance window, and other settings for the read replica
are the same as for the other nodes myReplicationGroup
.
https://elasticache.us-west-2.amazonaws.com/ ?Action=CreateCacheCluster &CacheClusterId=myReadReplica &ReplicationGroupId=myReplicationGroup &Version=2015-02-02 &SignatureVersion=4 &SignatureMethod=HmacSHA256 &Timestamp=20150202T192317Z &X-Amz-Credential=<credential>
For more information on adding a read replica using the API, see CreateCacheCluster in the Amazon ElastiCache API Reference.