Using REST monitoring

REST monitoring uses a similar API to Jolokia, but with a subset of the features. The REST API is hosted on the following URL:

Operations

REST monitoring supports a subset of operations defined in the Jolokia API.

Currently, this feature only supports the read operation since the feature is still in tech preview. More operations will become available in future releases

Read

The read operation reads the details of the requested MBean. The read operation accepts GET requests on URLs in the following format:

<REST_API_URL>/read/${mbean-name}/${attribute-name}

For example, if you want to read the MBean java.lang:type=Memory using the default configuration, you would make a GET request to: http://localhost:4848/rest-monitoring/rest/read/java.lang:type=Memory.

A sample output of this request is shown below:

{
  "request": {
    "mbean": "java.lang:type=Memory",
    "type": "read"
  },
  "value": {
    "HeapMemoryUsage": {
      "committed": 450363392,
      "init": 264241152,
      "max": 477626368,
      "used": 97480984
    },
    "ObjectPendingFinalizationCount": 0,
    "NonHeapMemoryUsage": {
      "committed": 139460608,
      "init": 2555904,
      "max": -1,
      "used": 122389432
    },
    "Verbose": false,
    "ObjectName": "java.lang:type=Memory"
  },
  "timestamp": 1502799650273,
  "status": 200
}

A couple of quick notes:

  • The attribute name can be empty

  • A list of attribute names can be found in the request of an empty attribute name under value. So in the example MBean above, HeapMemoryUsage and NonHeapMemoryUsage are both attribute names.

Not supported in the current technical preview included with Payara Server 5.2021.8.

List

Not supported in the current technical preview included with Payara Server 5.2021.8.

Write

Not supported in the current technical preview included with Payara Server 5.2021.8.

Version

The version operation is not fully supported in Payara Server 5.2021.8, but a GET request on the default operation produces similar results.

Bulk Operations

Since Payara Server 5.182

It is possible to execute bulk operations using the REST monitoring API too. To do this, just issue a POST request to the REST API URL with the following JSON structure as the body payload:

[
  {
    "type" : "<OPERATION_TYPE>",
    "mbean" : "<MBEAN_NAME>",
    "attribute" : "<ATTRIBUTE_NAME>"
  },
  {
    "type" : "<OPERATION_TYPE>",
    "mbean" : "<MBEAN_NAME>",
    "attribute" : "<ATTRIBUTE_NAME>"
  },
  ...
]

The payload is a JSON array consisting of objects with the following structure:

type

The type of the operation to execute (read, search, etc.)

mbean

The MBean name upon which the operation will be executed.

attribute

The MBean attribute upon which the operation will be executed. If ommited, all attributes of the MBean will be involved in the operation.

You can send only one operation request instead of an array if needed.
Since the feature is on tech preview, currently the only supported operation type is read.

Here’s an example of executing a bulk read operation:

curl -X POST \
  http://localhost:4848/rest-monitoring/rest/ \
  -H 'Content-Type: application/json' \
  -d '[
	{
		"mbean": "java.lang:type=Compilation",
		"type": "read"
	},{
		"mbean": "java.lang:type=Runtime",
		"attribute" : "Uptime",
		"type": "read"
	}
]'

Which will yield an output similar to the following:

[
    {
        "request": {
            "mbean": "java.lang:type=Compilation",
            "type": "read"
        },
        "value": {
            "Name": "HotSpot 64-Bit Tiered Compilers",
            "CompilationTimeMonitoringSupported": true,
            "TotalCompilationTime": 106363,
            "ObjectName": "java.lang:type=Compilation"
        },
        "timestamp": 1529353755633,
        "status": 200
    },
    {
        "request": {
            "mbean": "java.lang:type=Runtime",
            "attribute": "Uptime",
            "type": "read"
        },
        "value": 8541422,
        "timestamp": 1529353755636,
        "status": 200
    }
]