README.md

Prometheus Observability Provider

The Prometheus Observability provider manages the collection of various metrics for Tegola's various subsystems.

The connection between Tegola and Prometheus is configured in the config file (tegola.toml.) An example of minimum configuration :

[observer]
type = "prometheus"

The metrics will be exposed on the /metrics end point.

Configuration Properties

• type (string): [Required] the type of the observer, must be "prometheus".
• variables (array of strings): [Optional] A set of tokens that should be replaced in the url for HTTP or additional labels for cache providers. Currently, supported tokens are:
  • :map_name [Default]
  • :layer_name [Default]
  • :z [Default]
  • :x
  • :y
• push_url (string) : [Optional] To push to a Prometheus Gateway, set the push_url to the gateway's URL. Note: this should only be used for ephemeral jobs, such as tegola cache seed or tegola cache pruge commands.
• push_cadence (int) : [Optional] How often to push to the Prometheus Gateway. Defaults to 10 secs. Use a zero or less to only push at the end of the process.

Metrics exposed

tegola build info

tegola_build_info

A gauge with build information from the running command

Labels

• branch - if set, the git branch of this built binary
• revision - the git short revision number
• version - the set version number
• command - the running command
• tags - the build tags that were used to build the Tegola Binary

Use this in conjunction with other command to compare metrics across versions of the application.

tegola server api http handlers

tegola_api_duration_seconds

A histogram of latencies for requests.

As part of a histogram include the support tags:

• tegola_api_duration_seconds_sum
• tegola_api_duration_seconds_count

labels

• handler is the URL with variables substituted in as requested.
• method is the HTTP method used to request the resource
• le is the buckets in seconds

tegola_api_flight_requests

A gauge of requests currently being served by the wrapped handler.

tegola_api_requests_total

A counter for requests to the wrapped handler.

labels

• code is the returned HTTP code

tegola_api_response_size_bytes

A histogram of response sizes in bytes for requests.

As part of a histogram include the support tags:

• tegola_api_response_size_sum
• tegola_api_response_size_count

labels

• le is the buckets in bytes

tegola server viewer http handlers

tegola_viewer_duration_seconds

A histogram of latencies for requests.

As part of a histogram include the support tags:

• tegola_viewer_duration_seconds_sum
• tegola_viewer_duration_seconds_count

labels

• handler is the URL for the requested resource
• method is the HTTP method used to request the resource
• le is the buckets in seconds

tegola_viewer_flight_requests

A gauge of requests currently being served by the wrapped handler.

tegola_viewer_requests_total

A counter for requests to the wrapped handler.

labels

• code is the returned HTTP code

tegola_viewer_response_size_bytes

A histogram of response sizes in bytes for requests.

As part of a histogram include the support tags:

• tegola_viewer_response_size_sum
• tegola_viewer_response_size_count

labels

• le is the buckets in bytes

tegola cache

tegola_cache_flight_requests

A gauge of requests currently being handled by the cache

tegola_cache_hits_total

A counter of the number of tile hits

labels

• sub_command is the cache command which is one of "get","set", or "purge"
• layer_name is an optional label, that is the layer_name ; this is only present if configured via variables config option.
• map_name is an optional label, that is the map_name; this is only present if configured via variables config option.
• z is an optional label, that is the z coordinate; this is only present if configured via variables config option.
• x is an optional label, that is the x coordinate; this is only present if configured via variables config option.
• y is an optional label, that is the y coordinate; this is only present if configured via variables config option.

tegola_cache_misses_total

A counter of the number of tile hits

labels

• sub_command is the cache command which is one of "get","set", or "purge"
• layer_name is an optional label, that is the layer_name ; this is only present if configured via variables config option.
• map_name is an optional label, that is the map_name; this is only present if configured via variables config option.
• z is an optional label, that is the z coordinate; this is only present if configured via variables config option.
• x is an optional label, that is the x coordinate; this is only present if configured via variables config option.
• y is an optional label, that is the y coordinate; this is only present if configured via variables config option.

tegola_cache_duration_seconds

A histogram of latencies for requests.

As part of a histogram include the support tags:

• tegola_cache_duration_seconds_sum
• tegola_cache_duration_seconds_count

labels

• sub_command is the cache command which is one of "get","set", or "purge"
• layer_name is an optional label, that is the layer_name ; this is only present if configured via variables config option.
• map_name is an optional label, that is the map_name; this is only present if configured via variables config option.
• z is an optional label, that is the z coordinate; this is only present if configured via variables config option.
• x is an optional label, that is the x coordinate; this is only present if configured via variables config option.
• y is an optional label, that is the y coordinate; this is only present if configured via variables config option.
• le is the buckets in seconds

tegola_cache_response_size_bytes

A histogram of response sizes for requests.

As part of a histogram include the support tags:

• tegola_cache_response_size_sum
• tegola_cache_response_size_count

labels

• sub_command is the cache command which is one of "get","set", or "purge"
• layer_name is an optional label, that is the layer_name ; this is only present if configured via variables config option.
• map_name is an optional label, that is the map_name; this is only present if configured via variables config option.
• z is an optional label, that is the z coordinate; this is only present if configured via variables config option.
• x is an optional label, that is the x coordinate; this is only present if configured via variables config option.
• y is an optional label, that is the y coordinate; this is only present if configured via variables config option.
• le is the buckets in bytes

tegola data provider postgres

tegola_postgres_max_connections

The max number of postgres connections in the connection pool.

tegola_postgres_current_connections

The current number of postgres connections in the connection pool.

tegola_postgres_available_connections

The current number of available postgres connections in the connection pool.

tegola_mvt_provider_sql_query_seconds

Labels: "map_name", and "z" Buckets: .1 second, 1 second, 5 seconds, and 20+ seconds

A histogram of the query time for the SQLs for the mvt provider

tegola_provider_sql_query_seconds

Labels: "map_name", "layer_name", and "z" Buckets: .1 second, 1 second, 5 seconds, and 20+ seconds

A histogram of the query time for the SQLs for the provider

go runtime information

go_gc_duration_seconds

A summary of the pause duration of garbage collection cycles.

go_goroutines

Number of goroutines that currently exist.

go_info

Information about the Go environment.

go_memstats_alloc_bytes

Number of bytes allocated and still in use.

go_memstats_alloc_bytes_total

Total number of bytes allocated, even if freed.

go_memstats_buck_hash_sys_bytes

Number of bytes used by the profiling bucket hash table.

go_memstats_frees_total

Total number of frees.

go_memstats_gc_cpu_fraction

The fraction of this program's available CPU time used by the GC since the program started.

go_memstats_gc_sys_bytes

Number of bytes used for garbage-collection-system metadata.

go_memstats_heap_alloc_bytes

Number of heap bytes allocated and still in use.

go_memstats_heap_idle_bytes

Number of heap bytes waiting to be used.

go_memstats_heap_inuse_bytes

Number of heap bytes that are in use.

go_memstats_heap_objects

Number of allocated objects.

go_memstats_heap_released_bytes

Number of heap bytes released to OS.

go_memstats_heap_sys_bytes

Number of heap bytes obtained from system.

go_memstats_last_gc_time_seconds

Number of seconds since 1970 of last garbage collection.

go_memstats_lookups_total

Total number of pointer lookups.

go_memstats_mallocs_total

Total number of mallocs.

go_memstats_mcache_inuse_bytes

Number of bytes in use by mcache structures.

go_memstats_mcache_sys_bytes

Number of bytes used for mcache structures obtained from system.

go_memstats_mspan_inuse_bytes

Number of bytes in use by mspan structures.

go_memstats_mspan_sys_bytes

Number of bytes used for mspan structures obtained from system.

go_memstats_next_gc_bytes

Number of heap bytes when next garbage collection will take place.

go_memstats_other_sys_bytes

Number of bytes used for other system allocations.

go_memstats_stack_inuse_bytes

Number of bytes in use by the stack allocator.

go_memstats_stack_sys_bytes

Number of bytes obtained from system for stack allocator.

go_memstats_sys_bytes

Number of bytes obtained from system.

go_threads

Number of OS threads created.