Module metrics 

Prometheus metrics for the docspec-http server.

Each pod exposes its own /metrics endpoint. The Prometheus server scrapes each pod independently — no aggregation happens in-process.

Design

This module owns all metric-name and label constants. Middleware (see middleware) records values; this module only declares and describes them. Call install_global once at startup before accepting requests, then mount the closure returned by metrics_handler at /metrics.

Modules

middleware

Tower middleware for recording HTTP-level Prometheus metrics.

Constants

CONVERSION_DURATION_BUCKETS

Latency histogram buckets for document conversion duration, in seconds.

CONVERSION_OUTPUT_BYTES_BUCKETS

Size histogram buckets for conversion output bytes.

ERROR_CLASS_NONE

Value for LABEL_ERROR_CLASS when no error occurred.

HTTP_BODY_SIZE_BUCKETS

Body-size histogram buckets for HTTP request bodies, in bytes.

HTTP_LATENCY_BUCKETS

Latency histogram buckets for HTTP request duration, in seconds.

INPUT_MIME_HTML

Value for LABEL_INPUT_MIME_TYPE when the request was text/html.

INPUT_MIME_MARKDOWN

Value for LABEL_INPUT_MIME_TYPE when the request was text/markdown.

INPUT_MIME_NONE

Value for LABEL_INPUT_MIME_TYPE when the Content-Type header was absent.

INPUT_MIME_UNSUPPORTED

Value for LABEL_INPUT_MIME_TYPE when the Content-Type header was present but not a supported reader format.

LABEL_ERROR_CLASS

Label key for the error class when a conversion fails.

LABEL_INPUT_MIME_TYPE

Label key for the input MIME type of the conversion request.

LABEL_METHOD

Label key for the HTTP request method (GET, POST, …).

LABEL_OUTPUT_MIME_TYPE

Label key for the output MIME type produced by the conversion.

LABEL_PATH

Label key for the matched route path pattern.

LABEL_RESULT

Label key for the conversion outcome category.

LABEL_STATUS

Label key for the HTTP response status code.

METRIC_CONVERSIONS_TOTAL

Counter: total number of document conversions.

METRIC_CONVERSION_DURATION_SECONDS

Histogram: document conversion duration in seconds.

METRIC_CONVERSION_OUTPUT_BYTES

Histogram: document conversion output size in bytes.

METRIC_HTTP_REQUESTS_TOTAL

Counter: total number of HTTP requests received.

METRIC_HTTP_REQUEST_BODY_BYTES

Histogram: HTTP request body size in bytes.

METRIC_HTTP_REQUEST_DURATION_SECONDS

Histogram: HTTP request latency in seconds.

OUTPUT_MIME_BLOCKNOTE

Value for LABEL_OUTPUT_MIME_TYPE when the conversion produced BlockNote JSON.

OUTPUT_MIME_HTML

Value for LABEL_OUTPUT_MIME_TYPE when the conversion produced HTML.

OUTPUT_MIME_NONE

Value for LABEL_OUTPUT_MIME_TYPE when no output was produced (any error path).

OUTPUT_MIME_OXA

Value for LABEL_OUTPUT_MIME_TYPE when the conversion produced oxa.dev JSON.

PATH_UNKNOWN

Value for LABEL_PATH when no route was matched by the router.

RESULT_CLIENT_ERROR

Value for LABEL_RESULT when a conversion fails due to a client error.

RESULT_SERVER_ERROR

Value for LABEL_RESULT when a conversion fails due to a server error.

RESULT_SUCCESS

Value for LABEL_RESULT when a conversion succeeds.

Functions

build_recorder

Builds a configured PrometheusRecorder and its PrometheusHandle without installing it globally.

install_global

Installs the Prometheus recorder globally and registers HELP text for every metric.

metrics_handler

Returns a clone-safe handler closure that renders Prometheus metrics as an HTTP response with the correct Content-Type.