4.3. Configuring Clustering

4.3.1. Cluster Options

[cluster]

q

Sets the default number of shards for newly created databases. Thedefault value, 8, splits a database into 8 separate partitions.

[cluster]
q = 8

For systems with lots of small, infrequently accessed databases, orfor servers with fewer CPU cores, consider reducing this value to1 or 2.

The value of q can also be overridden on a per-DB basis, at DBcreation time.


See also

httpdomain:put:PUT /{db} </{db}>

n

Sets the number of replicas of each document in a cluster. CouchDB willonly place one replica per node in a cluster. When set up through theCluster Setup Wizard, a standalone singlenode will have n = 1, a two node cluster will have n = 2, andany larger cluster will have n = 3. It is recommended not to setn greater than 3.

[cluster]
n = 3

placement

Sets the cluster-wide replica placement policy when creating newdatabases. The value must be a comma-delimited list of strings of theformat zone_name:#, where zone_name is a zone as specified inthe nodes database and # is an integer indicating the number ofreplicas to place on nodes with a matching zone_name.

This parameter is not specified by default.

[cluster]
placement = metro-dc-a:2,metro-dc-b:1

See also

Placing a database on specific nodes

seedlist

An optional, comma-delimited list of node names that this node shouldcontact in order to join a cluster. If a seedlist is configured the _upendpoint will return a 404 until the node has successfully contacted atleast one of the members of the seedlist and replicated an up-to-date copyof the _nodes, _dbs, and _users system databases.

[cluster]seedlist = couchdb@node1.example.com,couchdb@node2.example.com

原文: http://docs.couchdb.org/en/stable/config/cluster.html