Checking Connections

reference

Node-connectivity can be checked, prior to the creation of an XDCR reference.

HTTP Method and URI

POST /xdcr/connectionPreCheck

Description

Each Data-Service node in an XDCR source cluster must be able to connect to each Data-Service node in a prospective target cluster. In 7.2.1+, the POST /xdcr/connectionPreCheck method and URI allow all required connections to be checked, prior to the creation of a reference. Used with the same URI, the GET method returns information on a specified, ongoing connection-check.

Curl Syntax

curl -X POST -u <username>:<password>
  http://<ip-address-or-domain-name>:8091/xdcr/connectionPreCheck
  -d name=<targetClusterName>
  -d hostname=<ip-address-or-domain-name-for-target-cluster>
  -d username=<username-for-target-cluster>
  -d password=<password-for-target-cluster>
  [-d demandEncryption=[ 0 | 1 ] ]
  [-d secureType=[ 'none' | 'half' | 'full'] ]
    [--data-urlencode "certificate=$(cat <local-pathname-to-target-root-certificate>)"]
    [--data-urlencode "clientCertificate=$(cat /Users/username/clientcert/travel-sample.pem)"]
    [--data-urlencode "clientKey=$(cat /Users/username/clientcert/travel-sample.key)"]

curl -X GET -u <username>:<password>
  http://<ip-address-or-domain-name>:8091/xdcr/connectionPreCheck?taskId=<taskId>

In the POST statement, the name must be the name assigned locally to the target cluster. In the GET statement, the taskID specified as the query parameter is one previously returned from a successful POST.

Responses

Success for the POST returns 200 OK and an object containing the hostname and username for the target, and a taskId of the form task/<localhost>/<integer>, where the specified integer is the unique identifier for the task.

For both POST and GET, failure to authenticate returns 401 Unauthorized. An incorrectly specified URI returns 404 Object Not Found.

For POST, failure to specify a hostname returns 400 Bad Request and the message "hostname (ip) is missing". Failure to specify a name returns 400 Bad Request and the message "cluster name is missing".

For GET, failure to specify a taskId returns 500 Internal Server Error and a message such as No taskID provided to get the pre-check results, or 1 query parameter, taskId expected, got 0.

When GET is successful, 200 OK is returned, with an object whose data includes one of the status messages listed below:

If a problem is encountered, the message may be either "This version of some or all the nodes doesn’t support the connection pre-check", or "Intra-cluster replication detected, skipping connection pre-check". (Note that no check is required when target and source are specified as the same cluster.)
If the check is still in progress, the message may be one of the following: "Sending requests to the peer", "P2PSend was successful, waiting for the node’s response", "Response obtained from the node, storing the results", or "P2P protocol successfully executed, no errors".
If the check is complete, the message is as follows: "Connection check was successful, no errors".

Examples

In the following example, a connection check is made from the local cluster to a remote cluster locally named as MyRemoteCluster, using the remote IP address 10.145.250.102. The output is piped to the jq program, to facilitate readability.

curl -v -X POST http://localhost:8091/xdcr/connectionPreCheck \
-u Administrator:password \
-d hostname=10.145.250.102 \
-d username=Administrator \
-d password=password \
-d name=MyRemoteCluster | jq '.'

If the call is successful, the connection-check is started, and an object such as the following is returned:

{
  "hostname": "10.145.250.102:8091",
  "taskId": "task/127.0.0.1/11",
  "username": "Administrator"
}

The taskId thus returned can now be used to return the status of the connection-check that has been started. The following example duly returns the current status of this connection-check:

curl -X GET -u Administrator:password \
"http://localhost:8091/xdcr/connectionPreCheck?taskId=task/127.0.0.1/10" | jq '.'

If successful, the call returns an object such as the following:

{
  "done": true,
  "result": {
    "10.145.250.101:8091": {
      "10.145.250.102:8091": [
        "Connection check was successful, no errors"
      ]
    }
  },
  "taskId": "task/127.0.0.1/11"
}

This indicates that the check has concluded, and was successful. Note that if the output contains "done": false, instead of "done": true, this means that the check is not yet complete: in this case, the GET call should be made again. (It may take as long as 60 seconds, following initiation of a connection-check, for the response to show "done": true.)