Health API

The Health API can be used for measuring node health.

Note

This API set is for a specific node; it is unavailable on the public server.

Health Checks

The node periodically runs all health checks, including health checks for each chain.

The frequency at which health checks are run can be specified with the --health-check-frequency flag.

The health checks that are run by the node are filterable. You can specify which health checks you want to see by using tags filters. Returned results will only include health checks that match the specified tags and global health checks like network, database etc. When filtered, the returned results will not show the full node health, but only a subset of filtered health checks. This means the node can still be unhealthy in unfiltered checks, even if the returned results show that the node is healthy. AvalancheGo supports using subnetIDs as tags.

GET Request

To get an HTTP status code response that indicates the node's health, make a GET request. If the node is healthy, it will return a 200 status code. If the node is unhealthy, it will return a 503 status code. In-depth information about the node's health is included in the response body.

Filtering

To filter GET health checks, add a tag query parameter to the request. The tag parameter is a string. For example, to filter health results by subnetID 29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL, use the following query:

curl 'http://localhost:9650/ext/health?tag=29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL'

In this example returned results will contain global health checks and health checks that are related to subnetID 29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL.

Note: This filtering can show healthy results even if the node is unhealthy in other Chains/Avalanche L1s.

In order to filter results by multiple tags, use multiple tag query parameters. For example, to filter health results by subnetID 29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL and 28nrH5T2BMvNrWecFcV3mfccjs6axM1TVyqe79MCv2Mhs8kxiY use the following query:

curl 'http://localhost:9650/ext/health?tag=29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL&tag=28nrH5T2BMvNrWecFcV3mfccjs6axM1TVyqe79MCv2Mhs8kxiY'

The returned results will include health checks for both subnetIDs as well as global health checks.

Endpoints

The available endpoints for GET requests are:

/ext/health returns a holistic report of the status of the node. Most operators should monitor this status.
/ext/health/health is the same as /ext/health.
/ext/health/readiness returns healthy once the node has finished initializing.
/ext/health/liveness returns healthy once the endpoint is available.

curl  -H 'Content-Type: application/json' --data '{
    "jsonrpc":"2.0",
    "id"     :1,
    "method" :"health.health",
    "params": {
        "tags": ["11111111111111111111111111111111LpoYY", "29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL"]
    }
}' 'http://localhost:9650/ext/health'

Example Response:

{
    "jsonrpc": "2.0",
    "result": {
        "checks": {
            "C": {
                "message": {
                    "engine": {
                        "consensus": {
                            "lastAcceptedHeight": 31273749,
                            "lastAcceptedID": "2Y4gZGzQnu8UjnHod8j1BLewHFVEbzhULPNzqrSWEHkHNqDrYL",
                            "longestProcessingBlock": "0s",
                            "processingBlocks": 0
                        },
                        "vm": null
                    },
                    "networking": {
                        "percentConnected": 0.9999592612587486
                    }
                },
                "timestamp": "2024-03-26T19:44:45.2931-04:00",
                "duration": 20375
            },
            "P": {
                "message": {
                    "engine": {
                        "consensus": {
                            "lastAcceptedHeight": 142517,
                            "lastAcceptedID": "2e1FEPCBEkG2Q7WgyZh1v4nt3DXj1HDbDthyhxdq2Ltg3shSYq",
                            "longestProcessingBlock": "0s",
                            "processingBlocks": 0
                        },
                        "vm": null
                    },
                    "networking": {
                        "percentConnected": 0.9999592612587486
                    }
                },
                "timestamp": "2024-03-26T19:44:45.293115-04:00",
                "duration": 8750
            },
            "X": {
                "message": {
                    "engine": {
                        "consensus": {
                            "lastAcceptedHeight": 24464,
                            "lastAcceptedID": "XuFCsGaSw9cn7Vuz5e2fip4KvP46Xu53S8uDRxaC2QJmyYc3w",
                            "longestProcessingBlock": "0s",
                            "processingBlocks": 0
                        },
                        "vm": null
                    },
                    "networking": {
                        "percentConnected": 0.9999592612587486
                    }
                },
                "timestamp": "2024-03-26T19:44:45.29312-04:00",
                "duration": 23291
            },
            "bootstrapped": {
                "message": [],
                "timestamp": "2024-03-26T19:44:45.293078-04:00",
                "duration": 3375
            },
            "database": {
                "timestamp": "2024-03-26T19:44:45.293102-04:00",
                "duration": 1959
            },
            "diskspace": {
                "message": {
                    "availableDiskBytes": 227332591616
                },
                "timestamp": "2024-03-26T19:44:45.293106-04:00",
                "duration": 3042
            },
            "network": {
                "message": {
                    "connectedPeers": 284,
                    "sendFailRate": 0,
                    "timeSinceLastMsgReceived": "293.098ms",
                    "timeSinceLastMsgSent": "293.098ms"
                },
                "timestamp": "2024-03-26T19:44:45.2931-04:00",
                "duration": 2333
            },
            "router": {
                "message": {
                    "longestRunningRequest": "66.90725ms",
                    "outstandingRequests": 3
                },
                "timestamp": "2024-03-26T19:44:45.293097-04:00",
                "duration": 3542
            }
        },
        "healthy": true
    },
    "id": 1
}

In this example response, every check has passed. So, the node is healthy.

Response Explanation:

checks is a list of health check responses.
- A check response may include a message with additional context.
- A check response may include an error describing why the check failed.
- timestamp is the timestamp of the last health check.
- duration is the execution duration of the last health check, in nanoseconds.
- contiguousFailures is the number of times in a row this check failed.
- timeOfFirstFailure is the time this check first failed.
healthy is true all the health checks are passing.

`health.readiness`

This method returns the last evaluation of the startup health check results.

Example Call:

curl  -H 'Content-Type: application/json' --data '{
    "jsonrpc":"2.0",
    "id"     :1,
    "method" :"health.readiness",
    "params": {
        "tags": ["11111111111111111111111111111111LpoYY", "29uVeLPJB1eQJkzRemU8g8wZDw5uJRqpab5U2mX9euieVwiEbL"]
    }
}' 'http://localhost:9650/ext/health'

Example Response:

{
    "jsonrpc": "2.0",
    "result": {
        "checks": {
            "bootstrapped": {
                "message": [],
                "timestamp": "2024-03-26T20:02:45.299114-04:00",
                "duration": 2834
            }
        },
        "healthy": true
    },
    "id": 1
}

In this example response, every check has passed. So, the node has finished the startup process.

Response Explanation:

checks is a list of health check responses.
- A check response may include a message with additional context.
- A check response may include an error describing why the check failed.
- timestamp is the timestamp of the last health check.
- duration is the execution duration of the last health check, in nanoseconds.
- contiguousFailures is the number of times in a row this check failed.
- timeOfFirstFailure is the time this check first failed.
healthy is true all the health checks are passing.

`health.liveness`

This method returns healthy.

Example Call:

curl  -H 'Content-Type: application/json' --data '{
    "jsonrpc":"2.0",
    "id"     :1,
    "method" :"health.liveness"
}' 'http://localhost:9650/ext/health'

Example Response:

{
    "jsonrpc": "2.0",
    "result": {
        "checks": {},
        "healthy": true
    },
    "id": 1
}

In this example response, the node was able to handle the request and mark the service as healthy.

Response Explanation:

checks is an empty list.
healthy is true.

Health Checks

Filterable Health Checks

GET Request

Filtering

Endpoints

JSON RPC Request

Format

Endpoint

Methods

`health.health`

`health.readiness`

`health.liveness`

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