Logger does not support an off-cluster Redis in Cluster mode

[Cryptophobia]

From @mariusmarais on June 8, 2017 10:11

Deploying Workflow with an off-cluster Redis configuration, where Redis itself is running in cluster mode, does not work.

Symptoms include deis logs working immediately after deploying a new app, but not again after some time. Viewing the deis-logger-xxx pod's logs show 100s of:

2017-06-08T10:00:04.75420277Z 2017/06/08 10:00:04 Error executing pipeline: MOVED 2589 172.20.0.39:6379

The MOVED error means the client needs to reissue the request to the named IP as per the Redis docs.

Please update documentation that Redis Cluster is not supported in the short term and investigate implementation of cluster mode in the longer term.

(FWIW: It's quite easy to boot up a Redis Cluster using AWS ElastiCache.)

Copied from original issue: deis/logger#143

[Cryptophobia]

From @jchauncey on June 8, 2017 12:29

Cc @krancour