{
  "id": "shard-placement-policy",
  "title": "Shard placement policy",
  "url": "https://redis.io/docs/latest/operate/rs/7.8/databases/memory-performance/shard-placement-policy/",
  "summary": "Detailed info about the shard placement policy.",
  "content": "In Redis Enterprise Software, the location of master and replica shards on the cluster nodes can impact the database and node performance.\nMaster shards and their corresponding replica shards are always placed on separate nodes for data resiliency.\nThe shard placement policy helps to maintain optimal performance and resiliency.\n\n\n\n## Shard placement policies\n\n### Dense shard placement policy\n\nIn the dense policy, the cluster places the database shards on as few nodes as possible.\nWhen the node is not able to host all of the shards, some shards are moved to another node to maintain optimal node health.\n\nFor example, for a database with two master and two replica shards on a cluster with three nodes and a dense shard placement policy,\nthe two master shards are hosted on one node and the two replica shards are hosted on another node.\n\nFor Redis on RAM databases without the OSS cluster API enabled, use the dense policy to optimize performance.\n\n\n\n*Figure: Three nodes with two master shards (red) and two replica shards (white) with a dense placement policy*\n\n### Sparse shard placement policy\n\nIn the sparse policy, the cluster places shards on as many nodes as possible to distribute the shards of a database across all available nodes.\nWhen all nodes have database shards, the shards are distributed evenly across the nodes to maintain optimal node health.\n\nFor example, for a database with two master and two replica shards on a cluster with three nodes and a sparse shard placement policy:\n\n- Node 1 hosts one of the master shards\n- Node 2 hosts the replica for the first master shard\n- Node 3 hosts the second master shard\n- Node 1 hosts for the replica shard for master shard 2\n\nFor Redis on RAM databases with OSS cluster API enabled and for databases with Auto Tiering enabled, use the sparse policy to optimize performance.\n\n\n\n*Figure: Three nodes with two master shards (red) and two replica shards (white) with a sparse placement policy*\n\n## Related articles\n\nYou can [configure the shard placement policy]() for each database.\n",
  "tags": ["docs","operate","rs"],
  "last_updated": "2026-04-01T08:10:08-05:00"
}