- Remove reference to 'unknown' state in catalog endpoint docs - Remove reference to 'unknown' state in health endpoint docs
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layout | page_title | sidebar_current | description |
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docs | Health Checks (HTTP) | docs-agent-http-health | The Health endpoints are used to query health-related information. |
Health HTTP Endpoint
The Health endpoints are used to query health-related information. They are provided separately from the Catalog since users may prefer not to use the optional health checking mechanisms. Additionally, some of the query results from the Health endpoints are filtered while the Catalog endpoints provide the raw entries.
The following endpoints are supported:
/v1/health/node/<node>
: Returns the health info of a node/v1/health/checks/<service>
: Returns the checks of a service/v1/health/service/<service>
: Returns the nodes and health info of a service/v1/health/state/<state>
: Returns the checks in a given state
All of the health endpoints support blocking queries and all consistency modes.
/v1/health/node/<node>
This endpoint is hit with a GET and returns the checks specific to the node provided on the path. By default, the datacenter of the agent is queried; however, the dc can be provided using the "?dc=" query parameter.
It returns a JSON body like this:
[
{
"Node": "foobar",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "",
"ServiceName": ""
},
{
"Node": "foobar",
"CheckID": "service:redis",
"Name": "Service 'redis' check",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "redis",
"ServiceName": "redis"
}
]
In this case, we can see there is a system level check (that is, a check with
no associated ServiceID
) as well as a service check for Redis. The "serfHealth" check
is special in that it is automatically present on every node. When a node
joins the Consul cluster, it is part of a distributed failure detection
provided by Serf. If a node fails, it is detected and the status is automatically
changed to critical
.
This endpoint supports blocking queries and all consistency modes.
/v1/health/checks/<service>
This endpoint is hit with a GET and returns the checks associated with the service provided on the path. By default, the datacenter of the agent is queried; however, the dc can be provided using the "?dc=" query parameter.
Adding the optional "?near=" parameter with a node name will sort the node list in ascending order based on the estimated round trip time from that node. Passing "?near=_agent" will use the agent's node for the sort.
It returns a JSON body like this:
[
{
"Node": "foobar",
"CheckID": "service:redis",
"Name": "Service 'redis' check",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "redis",
"ServiceName": "redis"
}
]
This endpoint supports blocking queries and all consistency modes.
/v1/health/service/<service>
This endpoint is hit with a GET and returns the nodes providing the service indicated on the path. By default, the datacenter of the agent is queried; however, the dc can be provided using the "?dc=" query parameter.
Adding the optional "?near=" parameter with a node name will sort the node list in ascending order based on the estimated round trip time from that node. Passing "?near=_agent" will use the agent's node for the sort.
By default, all nodes matching the service are returned. The list can be filtered by tag using the "?tag=" query parameter.
Providing the "?passing" query parameter, added in Consul 0.2, will filter results
to only nodes with all checks in the passing
state. This can be used to avoid extra filtering
logic on the client side.
This endpoint is very similar to the /v1/catalog/service endpoint; however, this endpoint automatically returns the status of the associated health check as well as any system level health checks. This allows a client to avoid sending traffic to nodes that are failing health tests or reporting warnings.
Users can also build in support for dynamic load balancing and other features by incorporating the use of health checks.
It returns a JSON body like this:
[
{
"Node": {
"Node": "foobar",
"Address": "10.1.10.12",
"TaggedAddresses": {
"lan": "10.1.10.12",
"wan": "10.1.10.12"
}
},
"Service": {
"ID": "redis",
"Service": "redis",
"Tags": null,
"Address": "10.1.10.12",
"Port": 8000
},
"Checks": [
{
"Node": "foobar",
"CheckID": "service:redis",
"Name": "Service 'redis' check",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "redis",
"ServiceName": "redis"
},
{
"Node": "foobar",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "",
"ServiceName": ""
}
]
}
]
This endpoint supports blocking queries and all consistency modes.
/v1/health/state/<state>
This endpoint is hit with a GET and returns the checks in the state provided on the path. By default, the datacenter of the agent is queried; however, the dc can be provided using the "?dc=" query parameter.
Adding the optional "?near=" parameter with a node name will sort the node list in ascending order based on the estimated round trip time from that node. Passing "?near=_agent" will use the agent's node for the sort.
The supported states are any
, passing
, warning
, or critical
.
The any
state is a wildcard that can be used to return all checks.
It returns a JSON body like this:
[
{
"Node": "foobar",
"CheckID": "serfHealth",
"Name": "Serf Health Status",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "",
"ServiceName": ""
},
{
"Node": "foobar",
"CheckID": "service:redis",
"Name": "Service 'redis' check",
"Status": "passing",
"Notes": "",
"Output": "",
"ServiceID": "redis",
"ServiceName": "redis"
}
]
This endpoint supports blocking queries and all consistency modes.