fix(ssubscribe): Force slots refresh on MOVED error when using ssubscribe #1987
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| if (item.command.name == "ssubscribe" && err.message.includes("MOVED")) { | ||
| this.redis.emit("moved"); | ||
| return; | ||
| } | ||
|
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Can you please add a comment here explaining how we use the standalone client for ssubscibe connections
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When a hashslot is moved to another shard the message that is sent on the pubsub channel is sunsubscribe, not moved. I suspect this is working because it's caught when the connection is retried. On issuing the ssubscribe command, the response is moved.
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I tried this again today and in fact there aren't any messages sent on the existing connection before it is closed. The connection is closed instantly during a failover, and then during retry, a MOVED error is received on SSUBSCRIBE as we assumed above.
elena-kolevska
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Jun 18, 2025
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When issuing a
ssubscribecommand, the Cluster client creates a "regular" Redis client to establish a connection to the correct shard. This doesn't work if there's a failover since the client doesn't know how to correctly handle aMOVEDresponse. This PR handles such events by propagating thessubscribe MOVEDerror from theDataHandler, through theClusterSubscriberand theClusterSubscriberGroupto theRedisClusterclient and forces slots refresh