[float]
[[monitoring]]
== APIs for monitoring {ls}

{ls} provides monitoring APIs for retrieving runtime metrics
about {ls}:

* <<node-info-api>>
* <<plugins-api>>
* <<node-stats-api>>
* <<hot-threads-api>>


You can use the root resource to retrieve general information about the Logstash instance, including
the host and version.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/?pretty'
--------------------------------------------------

Example response:

["source","js",subs="attributes"]
--------------------------------------------------
{
   "host": "skywalker",
   "version": "{logstash_version}",
   "http_address": "127.0.0.1:9600"
}
--------------------------------------------------

NOTE: By default, the monitoring API attempts to bind to `tcp:9600`. If this port is already in use by another Logstash
instance, you need to launch Logstash with the `--http.port` flag specified to bind to a different port. See
<<command-line-flags>> for more information.

[float]
[[monitoring-common-options]]
==== Common Options

The following options can be applied to all of the Logstash monitoring APIs.

[float]
===== Pretty Results

When appending `?pretty=true` to any request made, the JSON returned
will be pretty formatted (use it for debugging only!).

[float]
===== Human-Readable Output

NOTE: For Logstash {logstash_version}, the `human` option is supported for the <<hot-threads-api>>
only. When you specify `human=true`, the results are returned in plain text instead of
JSON format. The default is false.

Statistics are returned in a format suitable for humans
(eg `"exists_time": "1h"` or `"size": "1kb"`) and for computers
(eg `"exists_time_in_millis": 3600000` or `"size_in_bytes": 1024`).
The human-readable values can be turned off by adding `?human=false`
to the query string. This makes sense when the stats results are
being consumed by a monitoring tool, rather than intended for human
consumption.  The default for the `human` flag is
`false`.


[[node-info-api]]
=== Node Info API

The node info API retrieves information about the node.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/<types>'
--------------------------------------------------

Where `<types>` is optional and specifies the types of node info you want to return.

You can limit the info that's returned by combining any of the following types in a comma-separated list:

[horizontal]
<<node-pipeline-info,`pipelines`>>::
Gets pipeline-specific information and settings for each pipeline.
<<node-os-info,`os`>>::
Gets node-level info about the OS.
<<node-jvm-info,`jvm`>>::
Gets node-level JVM info, including info about threads.

See <<monitoring-common-options, Common Options>> for a list of options that can be applied to all
Logstash monitoring APIs.

[float]
[[node-pipeline-info]]
===== Pipeline Info

The following request returns a JSON document that shows pipeline info, such as the number of workers,
batch size, and batch delay:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/pipelines?pretty'
--------------------------------------------------

If you want to view additional information about a pipeline, such as stats for each configured input, filter,
or output stage, see the <<pipeline-stats>> section under the <<node-stats-api>>.

Example response:

["source","js",subs="attributes"]
--------------------------------------------------
{
  "pipelines" : {
    "test" : {
      "workers" : 1,
      "batch_size" : 1,
      "batch_delay" : 5,
      "config_reload_automatic" : false,
      "config_reload_interval" : 3
    },
    "test2" : {
      "workers" : 8,
      "batch_size" : 125,
      "batch_delay" : 5,
      "config_reload_automatic" : false,
      "config_reload_interval" : 3
    }
  }
--------------------------------------------------

You can see the info for a specific pipeline by including the pipeline ID. In
the following example, the ID of the pipeline is `test`:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/pipelines/test?pretty'
--------------------------------------------------

Example response:

[source,js]
----------
{
  "pipelines" : {
    "test" : {
      "workers" : 1,
      "batch_size" : 1,
      "batch_delay" : 5,
      "config_reload_automatic" : false,
      "config_reload_interval" : 3
    }
  }
----------

If you specify an invalid pipeline ID, the request returns a 404 Not Found error.

[float]
[[node-os-info]]
==== OS Info

The following request returns a JSON document that shows the OS name, architecture, version, and
available processors:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/os?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "os": {
    "name": "Mac OS X",
    "arch": "x86_64",
    "version": "10.12.4",
    "available_processors": 8
  }
--------------------------------------------------

[float]
[[node-jvm-info]]
==== JVM Info

The following request returns a JSON document that shows node-level JVM stats, such as the JVM process id, version,
VM info, memory usage, and info about garbage collectors:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/jvm?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "jvm": {
    "pid": 59616,
    "version": "1.8.0_65",
    "vm_name": "Java HotSpot(TM) 64-Bit Server VM",
    "vm_version": "1.8.0_65",
    "vm_vendor": "Oracle Corporation",
    "start_time_in_millis": 1484251185878,
    "mem": {
      "heap_init_in_bytes": 268435456,
      "heap_max_in_bytes": 1037959168,
      "non_heap_init_in_bytes": 2555904,
      "non_heap_max_in_bytes": 0
    },
    "gc_collectors": [
      "ParNew",
      "ConcurrentMarkSweep"
    ]
  }
}
--------------------------------------------------


[[plugins-api]]
=== Plugins Info API

The plugins info API gets information about all Logstash plugins that are currently installed.
This API basically returns the output of running the `bin/logstash-plugin list --verbose` command.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/plugins?pretty'
--------------------------------------------------

See <<monitoring-common-options, Common Options>> for a list of options that can be applied to all
Logstash monitoring APIs.

The output is a JSON document.

Example response:

["source","js",subs="attributes"]
--------------------------------------------------
{
  "total": 93,
  "plugins": [
    {
      "name": "logstash-codec-cef",
      "version": "4.1.2"
    },
    {
      "name": "logstash-codec-collectd",
      "version": "3.0.3"
    },
    {
      "name": "logstash-codec-dots",
      "version": "3.0.2"
    },
    {
      "name": "logstash-codec-edn",
      "version": "3.0.2"
    },
    .
    .
    .
  ]
--------------------------------------------------


[[node-stats-api]]
=== Node Stats API

The node stats API retrieves runtime stats about Logstash.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/<types>'
--------------------------------------------------

Where `<types>` is optional and specifies the types of stats you want to return.

By default, all stats are returned. You can limit the info that's returned by combining any of the following types in a comma-separated list:

[horizontal]
<<jvm-stats,`jvm`>>::
Gets JVM stats, including stats about threads, memory usage, garbage collectors,
and uptime.
<<process-stats,`process`>>::
Gets process stats, including stats about file descriptors, memory consumption, and CPU usage.
<<event-stats,`events`>>::
Gets event-related statistics for the Logstash instance (regardless of how many
pipelines were created and destroyed).
<<pipeline-stats,`pipelines`>>::
Gets runtime stats about each Logstash pipeline.
<<reload-stats,`reloads`>>::
Gets runtime stats about config reload successes and failures.
<<os-stats,`os`>>::
Gets runtime stats about cgroups when Logstash is running in a container.

See <<monitoring-common-options, Common Options>> for a list of options that can be applied to all
Logstash monitoring APIs.

[float]
[[jvm-stats]]
==== JVM Stats

The following request returns a JSON document containing JVM stats:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/jvm?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "jvm" : {
    "threads" : {
      "count" : 49,
      "peak_count" : 50
    },
    "mem" : {
      "heap_used_percent" : 14,
      "heap_committed_in_bytes" : 309866496,
      "heap_max_in_bytes" : 1037959168,
      "heap_used_in_bytes" : 151686096,
      "non_heap_used_in_bytes" : 122486176,
      "non_heap_committed_in_bytes" : 133222400,
      "pools" : {
        "survivor" : {
          "peak_used_in_bytes" : 8912896,
          "used_in_bytes" : 288776,
          "peak_max_in_bytes" : 35782656,
          "max_in_bytes" : 35782656,
          "committed_in_bytes" : 8912896
        },
        "old" : {
          "peak_used_in_bytes" : 148656848,
          "used_in_bytes" : 148656848,
          "peak_max_in_bytes" : 715849728,
          "max_in_bytes" : 715849728,
          "committed_in_bytes" : 229322752
        },
        "young" : {
          "peak_used_in_bytes" : 71630848,
          "used_in_bytes" : 2740472,
          "peak_max_in_bytes" : 286326784,
          "max_in_bytes" : 286326784,
          "committed_in_bytes" : 71630848
        }
      }
    },
    "gc" : {
      "collectors" : {
        "old" : {
          "collection_time_in_millis" : 607,
          "collection_count" : 12
        },
        "young" : {
          "collection_time_in_millis" : 4904,
          "collection_count" : 1033
        }
      }
    },
    "uptime_in_millis" : 1809643
  }
--------------------------------------------------

[float]
[[process-stats]]
==== Process Stats

The following request returns a JSON document containing process stats:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/process?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "process" : {
    "open_file_descriptors" : 184,
    "peak_open_file_descriptors" : 185,
    "max_file_descriptors" : 10240,
    "mem" : {
      "total_virtual_in_bytes" : 5486125056
    },
    "cpu" : {
      "total_in_millis" : 657136,
      "percent" : 2,
      "load_average" : {
        "1m" : 2.38134765625
      }
    }
  }
--------------------------------------------------

[float]
[[event-stats]]
==== Event Stats

The following request returns a JSON document containing event-related statistics
for the Logstash instance:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/events?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "events" : {
    "in" : 293658,
    "filtered" : 293658,
    "out" : 293658,
    "duration_in_millis" : 2324391,
    "queue_push_duration_in_millis" : 343816
  }
--------------------------------------------------

[float]
[[pipeline-stats]]
==== Pipeline Stats

The following request returns a JSON document containing pipeline stats,
including:

* the number of events that were input, filtered, or output by each pipeline
* stats for each configured filter or output stage
* info about config reload successes and failures
(when <<reloading-config,config reload>> is enabled)
* info about the persistent queue (when
<<persistent-queues,persistent queues>> are enabled)

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/pipelines?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "pipelines" : {
    "test" : {
      "events" : {
        "duration_in_millis" : 365495,
        "in" : 216485,
        "filtered" : 216485,
        "out" : 216485,
        "queue_push_duration_in_millis" : 342466
      },
      "plugins" : {
        "inputs" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-1",
          "events" : {
            "out" : 216485,
            "queue_push_duration_in_millis" : 342466
          },
          "name" : "beats"
        } ],
        "filters" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-2",
          "events" : {
            "duration_in_millis" : 55969,
            "in" : 216485,
            "out" : 216485
          },
          "failures" : 216485,
          "patterns_per_field" : {
            "message" : 1
          },
          "name" : "grok"
        }, {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-3",
          "events" : {
            "duration_in_millis" : 3326,
            "in" : 216485,
            "out" : 216485
          },
          "name" : "geoip"
        } ],
        "outputs" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-4",
          "events" : {
            "duration_in_millis" : 278557,
            "in" : 216485,
            "out" : 216485
          },
          "name" : "elasticsearch"
        } ]
      },
      "reloads" : {
        "last_error" : null,
        "successes" : 0,
        "last_success_timestamp" : null,
        "last_failure_timestamp" : null,
        "failures" : 0
      },
      "queue" : {
        "type" : "memory"
      }
    },
    "test2" : {
      "events" : {
        "duration_in_millis" : 2222229,
        "in" : 87247,
        "filtered" : 87247,
        "out" : 87247,
        "queue_push_duration_in_millis" : 1532
      },
      "plugins" : {
        "inputs" : [ {
          "id" : "d7ea8941c0fc48ac58f89c84a9da482107472b82-1",
          "events" : {
            "out" : 87247,
            "queue_push_duration_in_millis" : 1532
          },
          "name" : "twitter"
        } ],
        "filters" : [ ],
        "outputs" : [ {
          "id" : "d7ea8941c0fc48ac58f89c84a9da482107472b82-2",
          "events" : {
            "duration_in_millis" : 139545,
            "in" : 87247,
            "out" : 87247
          },
          "name" : "elasticsearch"
        } ]
      },
      "reloads" : {
        "last_error" : null,
        "successes" : 0,
        "last_success_timestamp" : null,
        "last_failure_timestamp" : null,
        "failures" : 0
      },
      "queue" : {
        "type" : "memory"
      }
    }
  }
--------------------------------------------------

You can see the stats for a specific pipeline by including the pipeline ID. In
the following example, the ID of the pipeline is `test`:

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/pipelines/test?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
    "test" : {
      "events" : {
        "duration_in_millis" : 365495,
        "in" : 216485,
        "filtered" : 216485,
        "out" : 216485,
        "queue_push_duration_in_millis" : 342466
      },
      "plugins" : {
        "inputs" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-1",
          "events" : {
            "out" : 216485,
            "queue_push_duration_in_millis" : 342466
          },
          "name" : "beats"
        } ],
        "filters" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-2",
          "events" : {
            "duration_in_millis" : 55969,
            "in" : 216485,
            "out" : 216485
          },
          "failures" : 216485,
          "patterns_per_field" : {
            "message" : 1
          },
          "name" : "grok"
        }, {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-3",
          "events" : {
            "duration_in_millis" : 3326,
            "in" : 216485,
            "out" : 216485
          },
          "name" : "geoip"
        } ],
        "outputs" : [ {
          "id" : "35131f351e2dc5ed13ee04265a8a5a1f95292165-4",
          "events" : {
            "duration_in_millis" : 278557,
            "in" : 216485,
            "out" : 216485
          },
          "name" : "elasticsearch"
        } ]
      },
      "reloads" : {
        "last_error" : null,
        "successes" : 0,
        "last_success_timestamp" : null,
        "last_failure_timestamp" : null,
        "failures" : 0
      },
      "queue" : {
        "type" : "memory"
      }
    }
  }
}
--------------------------------------------------

[float]
[[reload-stats]]
==== Reload Stats

The following request returns a JSON document that shows info about config reload successes and failures.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/reloads?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "reloads": {
    "successes": 0,
    "failures": 0
  }
}
--------------------------------------------------

[float]
[[os-stats]]
==== OS Stats

When Logstash is running in a container, the following request returns a JSON document that
contains cgroup information to give you a more accurate view of CPU load, including whether
the container is being throttled.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/stats/os?pretty'
--------------------------------------------------

Example response:

[source,js]
--------------------------------------------------
{
  "os" : {
    "cgroup" : {
      "cpuacct" : {
        "control_group" : "/elastic1",
        "usage_nanos" : 378477588075
                },
      "cpu" : {
        "control_group" : "/elastic1",
        "cfs_period_micros" : 1000000,
        "cfs_quota_micros" : 800000,
        "stat" : {
          "number_of_elapsed_periods" : 4157,
          "number_of_times_throttled" : 460,
          "time_throttled_nanos" : 581617440755
        }
      }
    }
  }
--------------------------------------------------


[[hot-threads-api]]
=== Hot Threads API

The hot threads API gets the current hot threads for Logstash. A hot thread is a
Java thread that has high CPU usage and executes for a longer than normal period
of time.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/hot_threads?pretty'
--------------------------------------------------

The output is a JSON document that contains a breakdown of the top hot threads for
Logstash.

Example response:

["source","sh",subs="attributes"]
--------------------------------------------------
{
  "hot_threads" : {
    "time" : "2017-06-06T18:25:28-07:00",
    "busiest_threads" : 3,
    "threads" : [ {
      "name" : "Ruby-0-Thread-7",
      "percent_of_cpu_time" : 0.0,
      "state" : "timed_waiting",
      "path" : "/path/to/logstash-{logstash_version}/vendor/bundle/jruby/1.9/gems/puma-2.16.0-java/lib/puma/thread_pool.rb:187",
      "traces" : [ "java.lang.Object.wait(Native Method)", "org.jruby.RubyThread.sleep(RubyThread.java:1002)", "org.jruby.RubyKernel.sleep(RubyKernel.java:803)" ]
    }, {
      "name" : "[test2]>worker3",
      "percent_of_cpu_time" : 0.85,
      "state" : "waiting",
      "traces" : [ "sun.misc.Unsafe.park(Native Method)", "java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)", "java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)" ]
    }, {
      "name" : "[test2]>worker2",
      "percent_of_cpu_time" : 0.85,
      "state" : "runnable",
      "traces" : [ "org.jruby.RubyClass.allocate(RubyClass.java:225)", "org.jruby.RubyClass.newInstance(RubyClass.java:856)", "org.jruby.RubyClass$INVOKER$i$newInstance.call(RubyClass$INVOKER$i$newInstance.gen)" ]
    } ]
  }
}
--------------------------------------------------

The parameters allowed are:

[horizontal]
`threads`:: 	        The number of hot threads to return. The default is 10.
`stacktrace_size`::     The depth of the stack trace to report for each thread. The default is 50.
`human`:: 	            If true, returns plain text instead of JSON format. The default is false.
`ignore_idle_threads`:: If true, does not return idle threads. The default is true.

See <<monitoring-common-options, Common Options>> for a list of options that can be applied to all
Logstash monitoring APIs.

You can use the `?human` parameter to return the document in a human-readable format.

[source,js]
--------------------------------------------------
curl -XGET 'localhost:9600/_node/hot_threads?human=true'
--------------------------------------------------

Example of a human-readable response:

["source","js",subs="attributes"]
--------------------------------------------------
 ::: {}
 Hot threads at 2017-06-06T18:31:17-07:00, busiestThreads=3:
 ================================================================================
 0.0 % of cpu usage, state: timed_waiting, thread name: 'Ruby-0-Thread-7'
 /path/to/logstash-{logstash_version}/vendor/bundle/jruby/1.9/gems/puma-2.16.0-java/lib/puma/thread_pool.rb:187
	 java.lang.Object.wait(Native Method)
	 org.jruby.RubyThread.sleep(RubyThread.java:1002)
	 org.jruby.RubyKernel.sleep(RubyKernel.java:803)
 --------------------------------------------------------------------------------
 0.0 % of cpu usage, state: waiting, thread name: 'defaultEventExecutorGroup-5-4'
	 sun.misc.Unsafe.park(Native Method)
	 java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
 --------------------------------------------------------------------------------
 0.05 % of cpu usage, state: timed_waiting, thread name: '[test]-pipeline-manager'
	 java.lang.Object.wait(Native Method)
	 java.lang.Thread.join(Thread.java:1253)
	 org.jruby.internal.runtime.NativeThread.join(NativeThread.java:75)

--------------------------------------------------
