Prometheus
Description
Expose metrics in Prometheus text-based exposition format.
The output table should have a proper structure.
Columns name (String) and value (number) are required.
Rows may optionally contain help (String) and timestamp (number).
Column type (String) is either counter, gauge, histogram, summary, untyped or empty.
Each metric value may also have some labels (Map(String, String)).
Several consequent rows may refer to the one metric with different labels. The table should be sorted by metric name (e.g., with ORDER BY name).
There are special requirements for labels for histogram and summary, see Prometheus doc for the details. Special rules applied to row with labels {'count':''} and {'sum':''}, they'll be converted to <metric_name>_count and <metric_name>_sum respectively.
Example Usage
Example:
┌─name────────────────────────────────┬─type──────┬─help──────────────────────────────────────┬─labels─────────────────────────┬────value─┬─────timestamp─┐
│ http_request_duration_seconds │ histogram │ A histogram of the request duration. │ {'le':'0.05'} │ 24054 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'le':'0.1'} │ 33444 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'le':'0.2'} │ 100392 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'le':'0.5'} │ 129389 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'le':'1'} │ 133988 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'le':'+Inf'} │ 144320 │ 0 │
│ http_request_duration_seconds │ histogram │ │ {'sum':''} │ 53423 │ 0 │
│ http_requests_total │ counter │ Total number of HTTP requests │ {'method':'post','code':'200'} │ 1027 │ 1395066363000 │
│ http_requests_total │ counter │ │ {'method':'post','code':'400'} │ 3 │ 1395066363000 │
│ metric_without_timestamp_and_labels │ │ │ {} │ 12.47 │ 0 │
│ rpc_duration_seconds │ summary │ A summary of the RPC duration in seconds. │ {'quantile':'0.01'} │ 3102 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'quantile':'0.05'} │ 3272 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'quantile':'0.5'} │ 4773 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'quantile':'0.9'} │ 9001 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'quantile':'0.99'} │ 76656 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'count':''} │ 2693 │ 0 │
│ rpc_duration_seconds │ summary │ │ {'sum':''} │ 17560473 │ 0 │
│ something_weird │ │ │ {'problem':'division by zero'} │ inf │ -3982045 │
└─────────────────────────────────────┴───────────┴───────────────────────────────────────────┴────────────────────────────────┴──────────┴───────────────┘
Will be formatted as:
# HELP http_request_duration_seconds A histogram of the request duration.
# TYPE http_request_duration_seconds histogram
http_request_duration_seconds_bucket{le="0.05"} 24054
http_request_duration_seconds_bucket{le="0.1"} 33444
http_request_duration_seconds_bucket{le="0.5"} 129389
http_request_duration_seconds_bucket{le="1"} 133988
http_request_duration_seconds_bucket{le="+Inf"} 144320
http_request_duration_seconds_sum 53423
http_request_duration_seconds_count 144320
# HELP http_requests_total Total number of HTTP requests
# TYPE http_requests_total counter
http_requests_total{code="200",method="post"} 1027 1395066363000
http_requests_total{code="400",method="post"} 3 1395066363000
metric_without_timestamp_and_labels 12.47
# HELP rpc_duration_seconds A summary of the RPC duration in seconds.
# TYPE rpc_duration_seconds summary
rpc_duration_seconds{quantile="0.01"} 3102
rpc_duration_seconds{quantile="0.05"} 3272
rpc_duration_seconds{quantile="0.5"} 4773
rpc_duration_seconds{quantile="0.9"} 9001
rpc_duration_seconds{quantile="0.99"} 76656
rpc_duration_seconds_sum 17560473
rpc_duration_seconds_count 2693
something_weird{problem="division by zero"} +Inf -3982045