Linkerd integration metrics

The official Datadog integration for monitoring Linkerd. It collects 91 metrics.

Definitions as of 2026-10-01

Official summary

Monitor your services health with metrics from linkerd.

Metric types

gauge (value at a point in time): 47
count (occurrences in the interval): 34
rate (per second): 10

Metrics

Descriptions are the official definitions, unedited.

Metric	Type	Unit
`linkerd.control.request.count`[OpenMetrics V2] Total count of control HTTP requests.	count	request
`linkerd.control.request_total`[OpenMetrics V1] Total count of control HTTP requests.	count	request
`linkerd.control.response.count`[OpenMetrics V2] Total count of control HTTP responses.	count	response
`linkerd.control.response_latency.count`Number of control responses on which the linkerd.control.response_latency.sum is evaluated.	gauge	response
`linkerd.control.response_latency.sum`Elapsed times between a control request's headers being received and its response stream completing.	gauge	millisecond
`linkerd.control.response_total`[OpenMetrics V1] Total count of control HTTP responses.	count	response
`linkerd.control.retry_skipped.count`[OpenMetrics V2] Total count of retryable control HTTP responses that were not retried.	count	response
`linkerd.control.retry_skipped_total`[OpenMetrics V1] Total count of retryable control HTTP responses that were not retried.	count	response
`linkerd.jvm.fd_count`(only available on Unix-based OS) A gauge of the number of open file descriptors (Linkerd v1 only).	gauge	unit
`linkerd.jvm.gc.ConcurrentMarkSweep.cycles`A gauge for ConcurrentMarkSweep of the total number of collections that have occurred (Linkerd v1 only).	gauge	unit
`linkerd.jvm.gc.ConcurrentMarkSweep.msec`A gauge for ConcurrentMarkSweep of the total elapsed time garbage collection pool doing collections, in milliseconds (Linkerd v1 only).	gauge	millisecond
`linkerd.jvm.gc.ParNew.cycles`A gauge for ParNew of the total number of collections that have occurred (Linkerd v1 only).	gauge	unit
`linkerd.jvm.gc.ParNew.msec`A gauge for ParNew of the total elapsed time garbage collection pool doing collections, in milliseconds (Linkerd v1 only).	gauge	millisecond
`linkerd.jvm.gc.cycles`A gauge of the number of the total number of collections that have occurred (Linkerd v1 only).	gauge	unit
`linkerd.jvm.gc.eden.pause_msec.quantile`Stats of the durations, in milliseconds, of the eden collection pauses (Linkerd v1 only).	gauge	millisecond
`linkerd.jvm.gc.msec`A gauge of the total elapsed time doing collections, in milliseconds (Linkerd v1 only).	gauge	millisecond
`linkerd.jvm.heap.committed`For the heap used for object allocation, a gauge of the amount of memory, in bytes, committed for the JVM to use (Linkerd v1 only).	gauge	byte
`linkerd.jvm.heap.max`For the heap used for object allocation, a gauge of the maximum amount of memory, in bytes, that can be used by the JVM (Linkerd v1 only).	gauge	byte
`linkerd.jvm.heap.used`For the heap used for object allocation, a gauge of the current amount of memory used, in bytes (Linkerd v1 only).	gauge	byte
`linkerd.jvm.mem.current.CMS_Old_Gen.used`A gauge of the of the current memory used, in bytes, for CMS_Old_Gen memory pool (Linkerd v1 only).	gauge	byte
`linkerd.jvm.mem.current.Par_Eden_Space.used`A gauge of the of the current memory used, in bytes, for Par_Eden_Space memory pool (Linkerd v1 only).	gauge	byte
`linkerd.jvm.mem.current.Par_Survivor_Space.used`A gauge of the of the current memory used, in bytes, for Par_Survivor_Space memory pool (Linkerd v1 only).	gauge	byte
`linkerd.jvm.nonheap.committed`For the non-heap memory, a gauge of the amount of memory, in bytes, committed for the JVM to use (Linkerd v1 only).	gauge	byte
`linkerd.jvm.nonheap.max`For the non-heap memory, a gauge of the maximum amount of memory, in bytes, that can be used by the JVM (Linkerd v1 only).	gauge	byte
`linkerd.jvm.nonheap.used`For the non-heap memory, a gauge of the current amount of memory used, in bytes (Linkerd v1 only).	gauge	byte
`linkerd.jvm.num_cpus`A gauge of the number of processors available to the JVM (Linkerd v1 only).	gauge	core
`linkerd.jvm.start_time`A gauge of the start time of the Java virtual machine in milliseconds since the epoch (Linkerd v1 only).	gauge	millisecond
`linkerd.jvm.thread.count`A gauge of the number of live threads including both daemon and non-daemon threads (Linkerd v1 only).	gauge	thread
`linkerd.jvm.uptime`A gauge of the uptime of the Java virtual machine in milliseconds (Linkerd v1 only).	gauge	millisecond
`linkerd.openmetrics.health`[OpenMetrics V2] Whether the check is able to connect to the metrics endpoint.	gauge	-
`linkerd.process.cpu_seconds.count`[OpenMetrics V2] Total user and system CPU time spent in seconds.	count	second
`linkerd.process.cpu_seconds_total`[OpenMetrics V1] Total user and system CPU time spent in seconds.	count	second
`linkerd.process.max_fds`Maximum number of open file descriptors.	gauge	file
`linkerd.process.open_fds`Number of open file descriptors.	gauge	file
`linkerd.process.resident_memory`Resident memory size in bytes.	gauge	byte
`linkerd.process.start_time`Time that the process started (in seconds since the UNIX epoch).	gauge	second
`linkerd.process.virtual_memory`Virtual memory size in bytes.	gauge	byte
`linkerd.prometheus.health`Whether the check is able to connect to the metrics endpoint.	gauge	-
`linkerd.request.count`[OpenMetrics V2] Total count of HTTP requests.	count	request
`linkerd.request_total`[OpenMetrics V1] Total count of HTTP requests.	count	request
`linkerd.response.count`[OpenMetrics V2] Total count of HTTP responses.	count	response
`linkerd.response_latency.count`Number of responses on which the linkerd.response_latency.sum metric is evaluated.	gauge	response
`linkerd.response_latency.sum`Elapsed times between a request's headers being received and its response stream completing.	gauge	millisecond
`linkerd.response_total`[OpenMetrics V1] Total count of HTTP responses.	count	response
`linkerd.retry_skipped.count`[OpenMetrics V2] Total count of retryable HTTP responses that were not retried.	count	response
`linkerd.retry_skipped_total`[OpenMetrics V1] Total count of retryable HTTP responses that were not retried.	count	response
`linkerd.route.actual_request.count`[OpenMetrics V2] Total count of actual route HTTP requests.	count	request
`linkerd.route.actual_request_total`[OpenMetrics V1] Total count of actual route HTTP requests.	count	request
`linkerd.route.actual_response.count`[OpenMetrics V2] Total count of actual route HTTP responses.	count	response
`linkerd.route.actual_response_latency.count`Number of responses on which the linkerd.route.actual_response_latency.sum is evaluated.	gauge	millisecond
`linkerd.route.actual_response_latency.sum`Elapsed times between a actual route request's headers being received and its response stream completing.	gauge	millisecond
`linkerd.route.actual_response_total`[OpenMetrics V1] Total count of actual route HTTP responses.	count	response
`linkerd.route.actual_retry_skipped.count`[OpenMetrics V2] Total count of retryable actual route HTTP responses that were not retried.	count	response
`linkerd.route.actual_retry_skipped_total`[OpenMetrics V1] Total count of retryable actual route HTTP responses that were not retried.	count	response
`linkerd.route.request.count`[OpenMetrics V2] Total count of route HTTP requests.	count	request
`linkerd.route.request_total`[OpenMetrics V1] Total count of route HTTP requests.	count	request
`linkerd.route.response.count`[OpenMetrics V2] Total count of route HTTP responses.	count	response
`linkerd.route.response_latency.count`Number of responses on which the linkerd.route.response_latency.sum metric is evaluated.	gauge	response
`linkerd.route.response_latency.sum`Elapsed times between a route request's headers being received and its response stream completing.	gauge	millisecond
`linkerd.route.response_total`[OpenMetrics V1] Total count of route HTTP responses.	count	response
`linkerd.route.retry_skipped.count`[OpenMetrics V2] Total count of retryable route HTTP responses that were not retried.	count	response
`linkerd.route.retry_skipped_total`[OpenMetrics V1] Total count of retryable route HTTP responses that were not retried.	count	response
`linkerd.rt.client.connections`Number of active connections for the client (Linkerd v1 only).	rate	connection
`linkerd.rt.client.connects_s`Number of connection par second for the client (Linkerd v1 only).	rate	connection/second
`linkerd.rt.client.pool_cached`A gauge of the number of connections cached for the client (Linkerd v1 only).	gauge	connection
`linkerd.rt.client.pool_num_too_many_waiters`A counter of the number of times there were no connections immediately available and there were already too many waiters (Linkerd v1 only).	gauge	unit
`linkerd.rt.client.pool_num_waited`A counter of the number of times there were no connections immediately available and the client waited for a connection (Linkerd v1 only).	gauge	unit
`linkerd.rt.client.pool_size`A gauge of the number of connections that are currently alive, either in use or not (Linkerd v1 only).	gauge	connection
`linkerd.rt.client.pool_waiters`A gauge of the number of clients waiting on connections (Linkerd v1 only).	gauge	unit
`linkerd.rt.client.request_latency_ms.quantile`Stats of the latency of requests in milliseconds for the client (Linkerd v1 only).	gauge	millisecond
`linkerd.rt.client.requests_s`Number of requests by second received by the client (Linkerd v1 only).	rate	-
`linkerd.rt.client.status.1XX_s`Number of request by second returning 1XX status code for the client (Linkerd v1 only).	rate	unit/second
`linkerd.rt.client.status.2XX_s`Number of request by second returning 2XX status code for the client (Linkerd v1 only).	rate	unit/second
`linkerd.rt.client.status.3XX_s`Number of request by second returning 3XX status code for the client (Linkerd v1 only).	rate	unit/second
`linkerd.rt.client.status.4XX_s`Number of request by second returning 4XX status code for the client (Linkerd v1 only).	rate	unit/second
`linkerd.rt.client.status.5XX_s`Number of request by second returning 5XX status code for the client (Linkerd v1 only).	rate	unit/second
`linkerd.rt.client.success_s`Number of success per second for the client (Linkerd v1 only).	rate	-
`linkerd.rt.server.connections`Number of active connections for the server (Linkerd v1 only).	gauge	connection
`linkerd.rt.server.connects_s`Number of connection par second for the server (Linkerd v1 only).	rate	connection/second
`linkerd.rt.server.request_latency_ms.quantile`Stats of the latency of requests in milliseconds for the server (Linkerd v1 only).	gauge	millisecond
`linkerd.tcp.close.count`[OpenMetrics V2] Total count of closed connections.	count	connection
`linkerd.tcp.close_total`[OpenMetrics V1] Total count of closed connections.	count	connection
`linkerd.tcp.connection_duration.count`Number of connections on which the linkerd.tcp.connection_duration.sum metric is evaluated.	gauge	connection
`linkerd.tcp.connection_duration.sum`Connection lifetimes.	gauge	millisecond
`linkerd.tcp.open.count`[OpenMetrics V2] Total count of opened connections.	count	connection
`linkerd.tcp.open_connections`Number of currently-open connections.	gauge	connection
`linkerd.tcp.open_total`[OpenMetrics V1] Total count of opened connections.	count	connection
`linkerd.tcp.read_bytes.count`[OpenMetrics V2] Total count of bytes read from peers.	count	byte
`linkerd.tcp.read_bytes_total`[OpenMetrics V1] Total count of bytes read from peers.	count	byte
`linkerd.tcp.write_bytes.count`[OpenMetrics V2] Total count of bytes written to peers.	count	byte
`linkerd.tcp.write_bytes_total`[OpenMetrics V1] Total count of bytes written to peers.	count	byte

Official documentation

Official documentation for the Linkerd integration

Metric names and descriptions are the official Datadog integration definitions (Copyright Datadog, Inc., BSD-3-Clause), reproduced unedited. The full license terms are on the About page.

Official summary

Metric types

Metrics

Official documentation

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