# DataSource Prometheus metrics

This page lists the Prometheus metrics published by DataSource applications.

Prometheus metrics are not published by default. To enable this feature, see [Publishing DataSource metrics in Prometheus format](datasource-configure-prometheus-monitoring.md#datasource).

## C and .NET DataSource metrics

This section describes Prometheus metrics published by .NET DataSource 8.0.0 applications and C DataSource 8.0.0+ applications.

Prometheus metrics are disabled by default. To enable Prometheus metrics in your DataSource application, set [`prometheus-port`](datasource-datasource-monitoring-configuration-part-1.md#prometheus-port) to a free port on the host.

The Prometheus metrics endpoint URI is `/metrics`.

For descriptions of additional metrics published by specific C DataSource applications, see the links below:

* [Liberator Prometheus metrics](../liberator/liberator-prometheus-metrics.md)
* [Transformer Prometheus metrics](../transformer/transformer-prometheus-metrics.md)

### C and .NET: process metrics

C and .NET DataSource applications publish the following metrics on the operating system process that runs the DataSource.

* **process_cpu_seconds_total**

  Total user and system CPU time spent in seconds.

  **Type:** Gauge
* **process_max_fds**

  The maximum number of file descriptors the process may have open (set by `ulimit` on  Linux).

  **Type:** Gauge
* **process_open_fds**

  Number of file descriptors the process has open.

  **Type:** Gauge
* **process_resident_memory_bytes**

  Resident memory size in bytes.

  ***Type:*** Gauge
* **process_start_time_seconds**

  Start time of the process (number of seconds since the start of the Unix epoch).

  **Type:** Gauge
* **process_virtual_memory_bytes**

  Virtual memory size in bytes.

  **Type:** Gauge
* **process_virtual_memory_max_bytes**

  Maximum amount of virtual memory available in bytes.

  **Type:** Gauge
* **dsdk_process_fds**

  Number of file descriptors the process has open.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | type | File descriptor type. Possible values: `non_socket_fds`, `socket_fds` |
* **dsdk_process_uptime_seconds_total**

  Process uptime in seconds.

  **Type:** Counter
* **dsdk_process_cputime_seconds_total**

  Process total CPU time in seconds.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | type | CPU time type. Possible values: `user`, `system` |
* **dsdk_process_delayed_threads**

  Count of delayed threads that have been delayed for 5 seconds or more. Delayed threads are an indication that the DataSource is under high load or that threads have locked up.

  **Type:** Gauge
* **dsdk_process_cpu_usage_percentage**

  Average CPU percentage used by the DataSource process in the period configured by the configuration option [`process-usage-period`](../datasource/datasource-datasource-monitoring-configuration-part-1.md#process-usage-period) (default 10 seconds).

  **Type:** Gauge
* **dsdk_process_total_cpu_usage_percentage**

  Total CPU percentage used by the DataSource process in the period configured by the configuration option [`process-usage-period`](../datasource/datasource-datasource-monitoring-configuration-part-1.md#process-usage-period) (default 10 seconds).

  **📌 NOTE**\
  This percentage can be greater than 100% if the DataSource is running with a system that has more than one core.

  **Type:** Gauge

  **Since:** DSDK 8.0.12
* **dsdk_process_num_cpus_total**

  The number of cores on the server.

  **Type:** Counter

  **Since:** DSDK 8.0.12
* **dsdk_process_thread_cpu_usage_percentage**

  Average CPU percentage used by the Caplin DataSource thread in the previous 500 milliseconds.

  **📌 NOTE**\
  This metric is only provided for Caplin DataSource threads. It is not provided for threads started by third-party libraries - for instance any threads started by a JVM if the DataSource loads one.

  **Type:** Gauge

  **Since:** DSDK 8.0.5

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | thread_name | the name of the DataSource thread |

### C and .NET: DataSource JVM metrics

Metrics for a JVM loaded by a DataSource.

**📌 NOTE**\
These metrics are reported when a DataSource loads a JVM, i.e. when [`jvm_location`](../datasource/datasource-java-jvm-configuration.md#jvm-location) is configured.

**Since:** DSDK 8.0.9 ( except where specified )

* **dsdk_jvm_gc_collection_seconds_count**

  The total number of garbage collections that have occurred.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | gc | the name of the memory manager |
* **dsdk_jvm_gc_collection_seconds_sum**

  The approximate accumulated collection elapsed time in seconds.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | gc | the name of the memory manager |
* **dsdk_jvm_memory_committed_bytes**

  The amount of memory in bytes that is committed for the Java virtual machine to use.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | area | the memory area: heap or non-heap |
* **dsdk_jvm_memory_init_bytes**

  The amount of memory in bytes that the Java virtual machine initially requests from the operating system for memory management.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | area | the memory area: heap or non-heap |
* **dsdk_jvm_memory_max_bytes**

  The maximum amount of memory in bytes that can be used for memory management..

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | area | the memory area: heap or non-heap |
* **dsdk_jvm_memory_used_bytes**

  The amount of used memory in bytes.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | area | the memory area: heap or non-heap |
* **dsdk_jvm_threads_current**

  The  current number of live threads including both daemon and non-daemon threads.

  **Type:** Gauge
* **dsdk_jvm_threads_daemon**

  The current number of live daemon threads.

  **Type:** Gauge
* **dsdk_jvm_threads_deadlocked**

  The of threads that are in deadlock waiting to acquire object monitors or ownable synchronizers.

  **Type:** Gauge
* **dsdk_jvm_threads_deadlocked_monitor**

  The threads that are in deadlock waiting to acquire object monitors.

  **Type:** Gauge
* **dsdk_jvm_threads_peak**

  The peak live thread count.

  **Type:** Gauge
* **dsdk_jvm_threads_started_total**

  The total number of threads created and also started since the Java virtual machine started.

  **Type:** Gauge

### C and .NET: DataSource peer metrics

Metrics for DataSource peer connections.

**📌 NOTE**\
To have peer metrics be reported under recognisable labels, add a `remote-label` option to the `add-peer` configuration of the connecting peer.

* **dsdk_peer_bytes_read_total**

  Total number of bytes read across all peer connections.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
* **dsdk_peer_bytes_written_total**

  Total number of bytes written across all peer connections.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
* **dsdk_peer_messages_read_total**

  Total number of messages read across all peer connections.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
  | icon:tag[] | message_type | the type of DataSource message. Possible values: `status`, `update` |
* **dsdk_peer_messages_written_total**

  Total number of messages written across all peer connections.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
  | icon:tag[] | message_type | the type of DataSource message. Possible values: `request`, `discard` |
* **dsdk_peer_pingpong_time_milliseconds**

  Average of the last ten heartbeat round-trip times.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
* **dsdk_peer_status**

  Status of the peer connection.

  **Type:** Gauge

  **Since:** DSDK 8.0.8

  **Values:**

  |     |     |     |
  | --- | --- | --- |
  | 0 | Peer connection is down |  |
  | 1 | Peer connection is up |  |

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |
* **dsdk_peer_active_subscriptions**

  Number of active subscriptions for the peer.

  **Type:** Gauge

  **Since:** DSDK 8.0.8

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | remote_label | the label of the DataSource peer |

### C: DataSource data-service metrics

C DataSources publish the following metrics for each [data service](datasource-data-services.md).

* **dsdk_data_service_messages_read_total**

  The total number of messages read from a data service.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | service_name | the data-service [name](../datasource/datasource-data-services-configuration.md#service-name) |
  | icon:tag[] | message_type | the type of message received. Possible values: `update`, `map`, `nodata` |
* **dsdk_data_service_bytes_read_total**

  The total number of bytes read from a data service.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | service_name | the data-service [name](../datasource/datasource-data-services-configuration.md#service-name) |
* **dsdk_data_service_bytes_written_total**

  The total number of bytes written to a data service (contributions).

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | service_name | the data-service [name](../datasource/datasource-data-services-configuration.md#service-name) |
* **dsdk_data_service_state**

  The state of a labelled data service. It has two possible values: `1` for up, `0` for down.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | service_name | the data-service [name](../datasource/datasource-data-services-configuration.md#service-name) |
* **dsdk_data_service_subscriptions**

  The number of open subscriptions associated with a data service.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | service_name | the data-service [name](../datasource/datasource-data-services-configuration.md#service-name) |
* **dsdk_data_service_response_time_milliseconds**

  The time taken for data services to respond to the first subscription request.

  **Type:** Histogram

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | le | the upper-bound of a histogram bucket. |

## Java DataSource metrics

This section describes Prometheus metrics published by all Java DataSources (8.0.0+) when [`prometheus-port`](datasource-datasource-monitoring-configuration-part-1.md#prometheus-port) is set.

The Prometheus metrics endpoint URI is `/metrics`. This can be customised for Java DataSources; see [`prometheus-endpoint`](datasource-datasource-monitoring-configuration-part-1.md#prometheus-endpoint).

### Java: process metrics

Metrics for the Java virtual machine (JVM), process, and system running the DataSource.

The JVM metrics available may differ depending on the JVM and garbage collector.

* **jvm_buffer_count_buffers**

  An estimate of the number of buffers in the pool.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | id | Buffer identifier. Examples: 'direct', 'mapped'. |
* **jvm_buffer_memory_used_bytes**

  An estimate of the memory that the Java virtual machine is using for this buffer pool.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | id | Buffer identifier. Examples: 'direct', 'mapped'. |
* **jvm_buffer_total_capacity_bytes**

  An estimate of the total capacity of the buffers in this pool.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | id | Buffer identifier. Examples: 'direct', 'mapped'. |
* **jvm_gc_live_data_size_bytes**

  Size of old generation memory pool after a full GC.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_gc_max_data_size_bytes**

  Max size of old generation memory pool.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_gc_memory_allocated_bytes_total**

  Incremented for an increase in the size of the young generation memory pool after one GC to before the next.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_gc_memory_promoted_bytes_total**

  Count of positive increases in the size of the old generation memory pool before GC to after GC.

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_gc_pause_seconds**

  Time spent in GC pause.

  **Type:** Summary

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | action | `end of major GC`, `end of minor GC` |
  | icon:tag[] | cause | `Metadata GC Threshold`, `Allocation Failure` |
* **jvm_gc_pause_seconds_max**

  Time spent in GC pause

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | action | `end of major GC`, `end of minor GC` |
  | icon:tag[] | cause | `Metadata GC Threshold`, `Allocation Failure` |
* **jvm_memory_committed_bytes**

  The amount of memory in bytes that is committed for the Java virtual machine to use

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | area | `heap`, `nonheap` |
  | icon:tag[] | id | memory block identifier. Examples: "G1 Eden Space", "G1 Old Gen" |
* **jvm_memory_max_bytes**

  The maximum amount of memory in bytes that can be used for memory management

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | area | `heap`, `nonheap` |
  | icon:tag[] | id | memory block identifier. Examples: "G1 Eden Space", "G1 Old Gen" |
* **jvm_memory_used_bytes**

  The amount of used memory.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | area | `heap`, `nonheap` |
  | icon:tag[] | id | memory block identifier. Examples: "G1 Eden Space", "G1 Old Gen" |
* **jvm_threads_daemon_threads**

  The current number of live daemon threads.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_threads_live_threads**

  The current number of live threads including both daemon and non-daemon threads.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_threads_peak_threads**

  The peak live thread count since the Java virtual machine started or peak was reset.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **jvm_threads_states_threads**

  The current number of threads having NEW state.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | state | `runnable`, `blocked`, `waiting`, `timed-waiting`, `new`, `terminated` |
* **process_cpu_usage**

  The "recent cpu usage" for the Java Virtual Machine process.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **process_start_time_seconds**

  Start time of the process since Unix epoch.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **process_uptime_seconds**

  The uptime of the Java virtual machine.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **system_cpu_count**

  The number of processors available to the Java virtual machine.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **system_cpu_usage**

  The "recent cpu usage" for the whole system.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
* **system_load_average_1m**

  The sum of the number of runnable entities queued to available processors and the number of runnable entities running on the available processors averaged over a period of time.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |

### Java: DataSource metrics

Metrics for Java DataSources.

* **datasource_cached_publisher_subscriptions**

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | name | Cached publisher identifier |
* **datasource_cached_publisher_messages_total**

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | name | Cached publisher identifier |
* **datasource_system_threads_delayed**

  Count of delayed threads that have been delayed for 5 seconds or more. Delayed threads are an indication that the DataSource is under high load or that threads have locked up.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |

### Java: DataSource peer metrics

Metrics for Java DataSource peer connections.

* **datasource_bytes_read**

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_bytes_written**

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_discard_average**

  Average duration of discarded requests from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_discard_count**

  Total number of discarded requests from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_discard_max**

  Duration in milliseconds of the longest discarded request from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_executor_queue_length**

  Total number of requests from a DataSource peer that are pending execution. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_messages_read**

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_netty_bytes_before_writable**

  How many bytes remain in underlying buffers until a thread can begin to process queued requests. See [`Channel.bytesBeforeWritable()`](https://netty.io/4.1/api/io/netty/channel/Channel.html#bytesBeforeWritable--) for more information. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_netty_bytes_before_unwritable**

  How many bytes can be written to underlying buffers until a thread must add new requests to the queue rather than process them immediately. See [`Channel.bytesBeforeUnwritable()`](https://netty.io/4.1/api/io/netty/channel/Channel.html#bytesBeforeUnwritable--) for more information. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |

* **datasource_messages_written**

  Total number of messages written to a specific DataSource peer.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_ping_pong_time**

  Average of the last ten heartbeat round-trip times.

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_request_average**

  Average duration of requests from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_request_count**

  Total number of requests made from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Counter

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |
* **datasource_request_max**

  Duration in milliseconds of the longest request from a DataSource peer. To configure the update frequency for this metric, see [`peer-debug-metrics-interval`](../datasource/datasource-datasource-peers-configuration-part-2.md#peer-debug-metrics-interval).

  **Type:** Gauge

  **Labels**

  |     |     |     |
  | --- | --- | --- |
  | icon:tag[] | app_name | DataSource [application name](../datasource/datasource-run-time-environment-configuration.md#application-name) |
  | icon:tag[] | peer_name | DataSource peer identifier |

---

**See also:**

* [Liberator Prometheus metrics](../liberator/liberator-prometheus-metrics.md)
* [Transformer Prometheus metrics](../transformer/transformer-prometheus-metrics.md)
* [`prometheus-port`](../datasource/datasource-datasource-monitoring-configuration-part-1.md#prometheus-port)
* [`prometheus-endpoint`](../datasource/datasource-datasource-monitoring-configuration-part-1.md#prometheus-endpoint)