AWS Elasticache Cluster

I deployed Elasticache AWS, 1 master and 1 read replica.

================Test1================
Tested using PECL + 1 Redis(master)
config:

define( ‘WP_REDIS_CLIENT’, ‘pecl’ );
define( ‘WP_REDIS_HOST’, ‘172.16.0.48’ );

Result: Working!
================Test1 END================

And then we decided that we need 1 master and 1 read replica.

Using this plugin guide.

================Test2================
Testing now with predis + 1 Redis(master) + 1 Redis(replica)

Config as below:

define( ‘WP_REDIS_CLIENT’, ‘predis’ );
define( ‘WP_REDIS_SERVERS’, [
‘tcp://127.16.0.1:6379?database=15&alias=master’,
‘tcp://127.16.0.2:6379?database=15&alias=replica-01’,
] );

Status: Not connected
================Test2 END================

Does anyone have tried master/slave predis setup?