Live replication from EC Single -> EC Single only performs snapshot.

[Cory Murphy]

Description

version: riot-redis v2.15.4

I'm having an issue where live replication to and from an elasticache 5.0.3 instance only performs a snapshot, and any new keys added to the source instance don't appear to be detected on the destination instance after waiting a reasonable amount of time. (up to a couple minutes) I have also tried using elasticache 6.2.5 instances with the same behavior.

How to Reproduce

1. Create two Elasticache 5.0.3 instances.
2. Start riot-redis

./riot-redis/bin/riot-redis --uri redis://source:6379 \
  replicate \
  --uri redis://destination:6379 \
  --mode live

3. set key on source instance

redis-cli -u redis://source:6379 set mykey myvalue
OK

4. wait at least 5 seconds
5. get key on destination instance. This returns nil for me.

redis-cli -u redis://destination:6379 get mykey
(nil)

[Julien Ruaux]

Are keyspace notifications enabled on the source database?

[Cory Murphy]

That fixed it, thank you! Appears to be disabled by default for Elasticache.