Collecting metrics via HTTP
Metrics can be collected from a server process via its HTTP interface by visiting
/metrics. The output of this page is
JSON for easy parsing by monitoring services. This endpoint accepts several GET parameters in its query string:
-
/metrics?metrics=<substring1>,<substring2>,…- Limits the returned metrics to those which contain at least one of the provided substrings. The substrings also match entity names, so this may be used to collect metrics for a specific tablet. -
/metrics?include_schema=1- Includes metrics schema information such as unit, description, and label in the JSON output. This information is typically omitted to save space. -
/metrics?compact=1- Eliminates unnecessary whitespace from the resulting JSON, which can decrease bandwidth when fetching this page from a remote host. -
/metrics?include_raw_histograms=1- Include the raw buckets and values for histogram metrics, enabling accurate aggregation of percentile metrics over time and across hosts.
For example:
$ curl -s 'http://example-ts:8050/metrics?include_schema=1&metrics=connections_accepted'
[
{
"type": "server",
"id": "kudu.tabletserver",
"attributes": {},
"metrics": [
{
"name": "rpc_connections_accepted",
"label": "RPC Connections Accepted",
"type": "counter",
"unit": "connections",
"description": "Number of incoming TCP connections made to the RPC server",
"value": 92
}
]
}
]$ curl -s 'http://example-ts:8050/metrics?metrics=log_append_latency'
[
{
"type": "tablet",
"id": "c0ebf9fef1b847e2a83c7bd35c2056b1",
"attributes": {
"table_name": "lineitem",
"partition": "hash buckets: (55), range: [(<start>), (<end>))",
"table_id": ""
},
"metrics": [
{
"name": "log_append_latency",
"total_count": 7498,
"min": 4,
"mean": 69.3649,
"percentile_75": 29,
"percentile_95": 38,
"percentile_99": 45,
"percentile_99_9": 95,
"percentile_99_99": 167,
"max": 367244,
"total_sum": 520098
}
]
}
]
