Hello, I am trying to connect Discourse with Redis cache cluster. I have multiple nodes in my redis cluster. I get following error in log. “CROSSSLOT Keys in request don’t hash to the same slot (Redis::CommandError)” As per Redis guidelines: When in cluster mode, Redis do not support multi-key operations where keys falls to the different key slots. “Redis Cluster implements all the single key commands available in the non-distributed version of Redis. Commands performing complex multi-key operations like Set type unions or intersections are implemented as well as long as the keys all belong to the same node.” I can see many of the redis operations in Discourse involves multi key operations. Find one such example as below. Does this mean that Discourse won’t be able to connect to redis in cluster mode? Are we limited to host Discourse with only one instance of redis in non cluster mode? lib/discourse_redis.rb main @redis.scan_each(**options) do |key| key = remove_namespace(key) if @namespace block.call(key) end else @redis .scan_each(**options) .map do |key| key = remove_namespace(key) if @namespace key end end end end def keys(pattern = nil) DiscourseRedis.ignore_readonly do pattern = pattern || "*" pattern = "#{namespace}:#{pattern}" if @namespace keys = @redis.keys(pattern) Any help would be greatly appreciated.

mhm, it is a pity. Just have run into a similar issue with an AWS Redis elasticache cluster while rebuilding the www app. I, [2017-10-12T21:12:38.058320 #13] INFO – : > cd /var/www/discourse && su discourse -c ‘bundle exec rake db:migrate’ URGENT: MOVED 1326 172.25.11.156:6379 Failed to initialize site default rake aborted! Redis::CommandError: MOVED 6976 172.25.11.156:6379 The Redis cluster is running on 4 nodes. Would be nice to get this solved. dig +short my-redis-cluster.clustercfg.euc1.cache.amazonaws.com 172.25.11.156 172.25.11.169 172.25.11.8 172.25.11.104

This is not going to be solved, just run slaves if you need HA, then you fail over to slave if master explodes

Discourse with Redis Cluster mode

Product Support Self-hosting

sam (Sam Saffron) 12 Outubro , 2017 21:13 2

No chance this will work, we use eval and on a cluster that can not work

Tópico		Respostas	Vistas
Installing Discourse on AWS Self-hosting	6	2204	4 Junho , 2018
Connection error to external Redis Self-hosting	1	240	2 Setembro , 2024
Multiple discourse on a single redis host Self-hosting hosting	3	1845	9 Junho , 2022
Switching to another Redis instance? Self-hosting	4	1376	10 Setembro , 2019
Shared Redis caching Self-hosting	1	1080	15 Dezembro , 2015

Discourse with Redis Cluster mode

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