Setting a Replica-Minimum

      A required minimum can be established for the number of replicas configured for a bucket.

      HTTP Methods and URIs

      POST /settings/dataService
      GET /settings/dataService


      Used with the POST method, the URI specifies an integer that establishes a required minimum for the number of replicas subsequently configured for every new bucket. Existing buckets are unaffected, and may continue to be used with their existing replica-configuration, even if the number is below the new minimum.

      Used with the GET method, the URI returns the current minimum.

      Curl Syntax

      curl -X POST http://<ip-address-or-domain-name>:8091/settings/dataService
        -u <username>:<password>
        -d minReplicasCount=<integer>
      curl -X GET http://<ip-address-or-domain-name>:8091/settings/dataService
        -u <username>:<password>

      The integer specified as the value of the minReplicasCount parameter must be an integer from 0 to 3. This integer establishes a minimum for the number of replicas that may be configured.


      Failure to authenticate returns 401 Unauthorized. An incorrectly expressed URI returns 404 Object Not Found. Specifying a minimum outside the required range returns 400 Bad Request, and the following object: {"errors":{"minReplicasCount":"The value must be in range from 0 to 3"}}.


      The following example establishes 2 as the minimum number of replicas required for each subsequently created bucket.

      curl -v -X POST http://localhost:8091/settings/dataService -d minReplicasCount=2 -u Administrator:password

      If successful, the call returns the following confirmation:


      The current established minimum number can be returned as follows:

      curl -v -X GET http://localhost:8091/settings/dataService -u Administrator:password

      Again, if the call is successful, the following confirmation is returned:


      In consequence of the established minimum, any attempt to create a bucket with a number of replicas that is less than the minimum generates an error, and the bucket is not created. The following example attempts to create a bucket with only 1 replica, while the established minimum is 2. The output is piped to the jq program, to facilitate readability:

      curl -v -X POST http://localhost:8091/pools/default/buckets -d name=testBucket1 -d ramQuota=100 -d replicaNumber=1 -u Administrator:password  | jq '.'

      This call fails with 400 Bad Request, and returns the following summary:

        "errors": {
          "replicaNumber": "Replica number must be equal to or greater than 2"
        "summaries": {
          "ramSummary": {
            "total": 1610612736,
            "otherBuckets": 0,
            "nodesCount": 3,
            "perNodeMegs": 100,
            "thisAlloc": 314572800,
            "thisUsed": 0,
            "free": 1296039936
          "hddSummary": {
            "total": 396484890624,
            "otherData": 17181011926,
            "otherBuckets": 0,
            "thisUsed": 0,
            "free": 379303878698

      The value of replicaNumber is a string describing the error. The summaries subdocument contains two objects: ramSummary and hddSummary, which respectively describe quota and usage for memory and disk. Figures are in Bytes, unless otherwise stated.

      See Also

      An explanation of replication is provided in vBuckets.