https://keyvaluestore.com/tags/redis-cluster/ Recent content in Redis Cluster on KeyValueStore.com Hugo en-us Mon, 05 Oct 2026 00:00:00 +0000 https://keyvaluestore.com/hash-slot-calculator-shows-the-redis-or-valkey-cluster-slot-for-any-key-and-catches-crossslot-errors/ Mon, 05 Oct 2026 00:00:00 +0000 https://keyvaluestore.com/hash-slot-calculator-shows-the-redis-or-valkey-cluster-slot-for-any-key-and-catches-crossslot-errors/ <p>Code that ran fine against a single Redis or Valkey server often breaks the day it moves to a cluster. An <code>MGET</code>, a <code>MULTI</code> block or a Lua script that touched three keys now gets <code>CROSSSLOT Keys in request don't hash to the same slot</code>, because in a cluster those keys live on different servers.</p> <p>The <a href="https://keyvaluestore.com/tools/slots/">Hash Slot Calculator</a> shows where keys land before that happens. Type a key and you get its slot and the primary that holds it, with the hashed part of the key marked. Paste a command and it tells you whether a cluster would run it. Paste a whole key list and it shows how the keys spread across your primaries, the busiest slots and the hash tags in use.</p>