Ray dependency on redis

Ray Core
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  • Do we still have redis as a hard dependency? If not, is there a hack/quick way to mitigate dependency? Is there any timeline for this dependency to be removed?
  • Can we connect to external redis server?
  • Can I use same external redis server to connect to multiple ray clusters?
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cc @Mingwei

  • Do we still have redis as a hard dependency? If not, is there a hack/quick way to mitigate dependency? Is there any timeline for this dependency to be removed?

No. The primary reason why we still have it as hard dep is because of many legacy code, but we are able to almost remove everything and remove it from hard dependency. I think Ray 1.11 or 1.12 will not contain Redis as a default dependency.

  • Can we connect to external redis server?

This is technically possible, but not supported. We are planning to have better support after we remove Redis from the default dependency. This will also be a way to achieve HA on top of Ray (by using external fault tolerant storage).

Can I use same external redis server to connect to multiple ray clusters?

Not recommended. It is not tested, and I think it is highly likely broken.

1 Like
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Thanks @sangcho for the detailed answers. Just to add a point about external Redis. You will be able to enable external Redis when starting Ray, with RAY_REDIS_ADDRESS=... ray start --head, in Ray nightly or the upcoming 1.11. The feature has users, but there is no stability guarantee yet.