3.3. Configuring Clustering¶
3.3.1. Cluster Options¶
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[cluster]¶ -
q¶
Sets the default number of shards for newly created databases. The default value,
8, splits a database into 8 separate partitions.[cluster] q = 8
For systems with lots of small, infrequently accessed databases, or for servers with fewer CPU cores, consider reducing this value to
1or2.The value of
qcan also be overridden on a per-DB basis, at DB creation time.See also
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n¶
Sets the number of replicas of each document in a cluster. CouchDB will only place one replica per node in a cluster. When set up through the Cluster Setup Wizard, a standalone single node will have
n = 1, a two node cluster will haven = 2, and any larger cluster will haven = 3. It is recommended not to setngreater than3.[cluster] n = 3
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placement¶
Warning
Use of this option will override the
noption for replica cardinality. Use with care.Sets the cluster-wide replica placement policy when creating new databases. The value must be a comma-delimited list of strings of the format
zone_name:#, wherezone_nameis a zone as specified in thenodesdatabase and#is an integer indicating the number of replicas to place on nodes with a matchingzone_name.This parameter is not specified by default.
[cluster] placement = metro-dc-a:2,metro-dc-b:1
See also
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seedlist¶
An optional, comma-delimited list of node names that this node should contact in order to join a cluster. If a seedlist is configured the
_upendpoint will return a 404 until the node has successfully contacted at least one of the members of the seedlist and replicated an up-to-date copy of the_nodes,_dbs, and_userssystem databases.[cluster] seedlist = couchdb@node1.example.com,couchdb@node2.example.com-