Looking for Confluent Cloud Schema Management docs? These pages cover some aspects of Schema Registry that are generally applicable, such as general concepts, schema formats, hybrid use cases, and tutorials, but the main focus here is Confluent Platform. For Confluent Cloud documentation, check out Manage Schemas on Confluent Cloud.

Monitoring Schema Registry

Schema Registry reports a variety of metrics through Java Management Extensions (JMX). It can also be configured to report stats using additional pluggable stats reporters using the metric.reporters configuration option. The easiest way to view the available metrics is to use jconsole to browse JMX MBeans.

Schema Registry has two types of metrics. Global metrics help you monitor the overall health of the service. Per-endpoint metrics monitor each API endpoint request method and are prefixed by a name of the endpoint (e.g. subjects.get-schema). These help you understand how the proxy is being used and track down specific performance problems.

Tip

Authentication is disabled for JMX by default in Kafka. You must use environment variables to override these defaults. For each platform component, the options to override the JMX defaults take the form <component-name>_JMX_OPTS. Use the following environment variable to override default JMX options for Schema Registry: SCHEMA_REGISTRY_JMX_OPTS.

Global Metrics

MBean: kafka.schema.registry:type=jetty-metrics

connections-active
Total number of active TCP connections.
connections-accepted-rate (deprecated since 2.0)
  • In 1.x: The average rate per second of accepted TCP connections.
  • In 2.x: Same as connections-opened-rate.
connections-opened-rate
The average rate per second of opened TCP connections.
connections-closed-rate
The average rate per second of closed TCP connections.

MBean: kafka.schema.registry:type=master-slave-role

master-slave-role
The current role of this Schema Registry instance. A value of 1 indicates this instance is the primary, 0 indicates it is a secondary.

Per-Endpoint Metrics

The following are the metrics available for each endpoint request method. Metrics for all requests are also aggregated into a global instance for each one. These aggregate instances have no prefix in their name.

MBean: kafka.schema.registry:type=jersey-metrics

<endpoint>.request-byte-rate
Bytes/second of incoming requests
<endpoint>.request-error-rate
The average number of requests per second that resulted in HTTP error responses
<endpoint>.request-latency-avg
The average request latency in ms
<endpoint>.request-latency-max
The maximum request latency in ms
<endpoint>.request-rate
The average number of HTTP requests per second.
<endpoint>.request-size-avg
The average request size in bytes
<endpoint>.request-size-max
The maximum request size in bytes
<endpoint>.response-byte-rate
Bytes/second of outgoing responses
<endpoint>.response-rate
The average number of HTTP responses per second.
<endpoint>.response-size-avg
The average response size in bytes
<endpoint>.response-size-max
The maximum response size in bytes

Endpoints

The following is a list of all the API endpoint methods. The naming should map intuitively to each of the API operations. To create a full metric name, prefix a per-endpoint metric name with one of these values. For example, to find the rate of GET /brokers API calls, combine the endpoint name brokers.list with the metric name request-rate to get brokers.list.request-rate.

compatibility.subjects.versions.verify POST /compatibility/subjects/{subject}/versions/{version}
schemas.ids.get-schema GET /schemas/ids/{id}
subjects.get-schema POST /subjects/{subject}
subjects.list GET /subjects
subjects.versions.get-schema GET /subjects/{subject}/versions/{version}
subjects.versions.get-schema.only GET /subjects/{subject}/versions/{version}/schema
subjects.versions.list GET /subjects/{subject}/versions
subjects.versions.register POST /subjects/{subject}/versions