JedisCluster Replication and EVAL

Question

I know that Jedis (and other client libs) can select an appropriate shard to execute the Lua script. However what I cannot find is how the master-slave nodes are used after. Say I have multiple Lua scripts and part of them does writes, another part - reads. How does Jedis know whether it should be executed on master or slave considering slaves are read-only?

Does it always send EVAL commands to master even for read-only scripts?

score 2 · Answer 1 · answered Apr 17 '18 at 16:29

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Jedis sends all commands to master nodes in cluster mode. By all, I mean all sorts of Redis commands, not only EVAL commands.

Jedis may use slave nodes, but it's only during internal cluster configuration.

answered Apr 17 '18 at 16:29

sazzad

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Thanks for your reply. Isn't this very performance-killing? I'd still would use replicas for HA, but reading from them would be nice too. Can you also provide a link for me confirming this behavior? – Nestor Sokil Apr 18 '18 at 08:05

score 1 · Accepted Answer · answered Apr 20 '18 at 12:45

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JedisCluster does not support Slaves as of now.

ReadOnly access to Slaves is in development

You may try to select slave nodes manually like examples here

answered Apr 20 '18 at 12:45

igord

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JedisCluster Replication and EVAL

2 Answers2