Add core metrics service (#58623) (#59122)

* create base service and collectors

* wire the service into server, add mock

* add collector tests

* add main collector test

* export metric types from server

* add service and server tests

* updates generated doc

* improve doc

* nits and comments

* add disconnected requests test

docs/development/core/server/kibana-plugin-server.md

@@ -88,11 +88,16 @@ The plugin integrates with the core system via lifecycle events: `setup`<!-- -->
 |  [Logger](./kibana-plugin-server.logger.md) | Logger exposes all the necessary methods to log any type of information and this is the interface used by the logging consumers including plugins. |
 |  [LoggerFactory](./kibana-plugin-server.loggerfactory.md) | The single purpose of <code>LoggerFactory</code> interface is to define a way to retrieve a context-based logger instance. |
 |  [LogMeta](./kibana-plugin-server.logmeta.md) | Contextual metadata |
+|  [MetricsServiceSetup](./kibana-plugin-server.metricsservicesetup.md) | APIs to retrieves metrics gathered and exposed by the core platform. |
 |  [OnPostAuthToolkit](./kibana-plugin-server.onpostauthtoolkit.md) | A tool set defining an outcome of OnPostAuth interceptor for incoming request. |
 |  [OnPreAuthToolkit](./kibana-plugin-server.onpreauthtoolkit.md) | A tool set defining an outcome of OnPreAuth interceptor for incoming request. |
 |  [OnPreResponseExtensions](./kibana-plugin-server.onpreresponseextensions.md) | Additional data to extend a response. |
 |  [OnPreResponseInfo](./kibana-plugin-server.onpreresponseinfo.md) | Response status code. |
 |  [OnPreResponseToolkit](./kibana-plugin-server.onpreresponsetoolkit.md) | A tool set defining an outcome of OnPreAuth interceptor for incoming request. |
+|  [OpsMetrics](./kibana-plugin-server.opsmetrics.md) | Regroups metrics gathered by all the collectors. This contains metrics about the os/runtime, the kibana process and the http server. |
+|  [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) | OS related metrics |
+|  [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md) | Process related metrics |
+|  [OpsServerMetrics](./kibana-plugin-server.opsservermetrics.md) | server related metrics |
 |  [PackageInfo](./kibana-plugin-server.packageinfo.md) |  |
 |  [Plugin](./kibana-plugin-server.plugin.md) | The interface that should be returned by a <code>PluginInitializer</code>. |
 |  [PluginConfigDescriptor](./kibana-plugin-server.pluginconfigdescriptor.md) | Describes a plugin configuration properties. |

docs/development/core/server/kibana-plugin-server.metricsservicesetup.getopsmetrics_.md

@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [MetricsServiceSetup](./kibana-plugin-server.metricsservicesetup.md) &gt; [getOpsMetrics$](./kibana-plugin-server.metricsservicesetup.getopsmetrics_.md)
+
+## MetricsServiceSetup.getOpsMetrics$ property
+
+Retrieve an observable emitting the [OpsMetrics](./kibana-plugin-server.opsmetrics.md) gathered. The observable will emit an initial value during core's `start` phase, and a new value every fixed interval of time, based on the `opts.interval` configuration property.
+
+<b>Signature:</b>
+
+```typescript
+getOpsMetrics$: () => Observable<OpsMetrics>;
+```
+
+## Example
+
+
+```ts
+core.metrics.getOpsMetrics$().subscribe(metrics => {
+  // do something with the metrics
+})
+
+```
+

docs/development/core/server/kibana-plugin-server.metricsservicesetup.md

@@ -0,0 +1,20 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [MetricsServiceSetup](./kibana-plugin-server.metricsservicesetup.md)
+
+## MetricsServiceSetup interface
+
+APIs to retrieves metrics gathered and exposed by the core platform.
+
+<b>Signature:</b>
+
+```typescript
+export interface MetricsServiceSetup 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [getOpsMetrics$](./kibana-plugin-server.metricsservicesetup.getopsmetrics_.md) | <code>() =&gt; Observable&lt;OpsMetrics&gt;</code> | Retrieve an observable emitting the [OpsMetrics](./kibana-plugin-server.opsmetrics.md) gathered. The observable will emit an initial value during core's <code>start</code> phase, and a new value every fixed interval of time, based on the <code>opts.interval</code> configuration property. |
+

docs/development/core/server/kibana-plugin-server.opsmetrics.concurrent_connections.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md) &gt; [concurrent\_connections](./kibana-plugin-server.opsmetrics.concurrent_connections.md)
+
+## OpsMetrics.concurrent\_connections property
+
+number of current concurrent connections to the server
+
+<b>Signature:</b>
+
+```typescript
+concurrent_connections: OpsServerMetrics['concurrent_connections'];
+```

docs/development/core/server/kibana-plugin-server.opsmetrics.md

@@ -0,0 +1,24 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md)
+
+## OpsMetrics interface
+
+Regroups metrics gathered by all the collectors. This contains metrics about the os/runtime, the kibana process and the http server.
+
+<b>Signature:</b>
+
+```typescript
+export interface OpsMetrics 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [concurrent\_connections](./kibana-plugin-server.opsmetrics.concurrent_connections.md) | <code>OpsServerMetrics['concurrent_connections']</code> | number of current concurrent connections to the server |
+|  [os](./kibana-plugin-server.opsmetrics.os.md) | <code>OpsOsMetrics</code> | OS related metrics |
+|  [process](./kibana-plugin-server.opsmetrics.process.md) | <code>OpsProcessMetrics</code> | Process related metrics |
+|  [requests](./kibana-plugin-server.opsmetrics.requests.md) | <code>OpsServerMetrics['requests']</code> | server requests stats |
+|  [response\_times](./kibana-plugin-server.opsmetrics.response_times.md) | <code>OpsServerMetrics['response_times']</code> | server response time stats |
+

docs/development/core/server/kibana-plugin-server.opsmetrics.os.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md) &gt; [os](./kibana-plugin-server.opsmetrics.os.md)
+
+## OpsMetrics.os property
+
+OS related metrics
+
+<b>Signature:</b>
+
+```typescript
+os: OpsOsMetrics;
+```

docs/development/core/server/kibana-plugin-server.opsmetrics.process.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md) &gt; [process](./kibana-plugin-server.opsmetrics.process.md)
+
+## OpsMetrics.process property
+
+Process related metrics
+
+<b>Signature:</b>
+
+```typescript
+process: OpsProcessMetrics;
+```

docs/development/core/server/kibana-plugin-server.opsmetrics.requests.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md) &gt; [requests](./kibana-plugin-server.opsmetrics.requests.md)
+
+## OpsMetrics.requests property
+
+server requests stats
+
+<b>Signature:</b>
+
+```typescript
+requests: OpsServerMetrics['requests'];
+```

docs/development/core/server/kibana-plugin-server.opsmetrics.response_times.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsMetrics](./kibana-plugin-server.opsmetrics.md) &gt; [response\_times](./kibana-plugin-server.opsmetrics.response_times.md)
+
+## OpsMetrics.response\_times property
+
+server response time stats
+
+<b>Signature:</b>
+
+```typescript
+response_times: OpsServerMetrics['response_times'];
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.distro.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [distro](./kibana-plugin-server.opsosmetrics.distro.md)
+
+## OpsOsMetrics.distro property
+
+The os distrib. Only present for linux platforms
+
+<b>Signature:</b>
+
+```typescript
+distro?: string;
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.distrorelease.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [distroRelease](./kibana-plugin-server.opsosmetrics.distrorelease.md)
+
+## OpsOsMetrics.distroRelease property
+
+The os distrib release, prefixed by the os distrib. Only present for linux platforms
+
+<b>Signature:</b>
+
+```typescript
+distroRelease?: string;
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.load.md

@@ -0,0 +1,17 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [load](./kibana-plugin-server.opsosmetrics.load.md)
+
+## OpsOsMetrics.load property
+
+cpu load metrics
+
+<b>Signature:</b>
+
+```typescript
+load: {
+        '1m': number;
+        '5m': number;
+        '15m': number;
+    };
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.md

@@ -0,0 +1,26 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md)
+
+## OpsOsMetrics interface
+
+OS related metrics
+
+<b>Signature:</b>
+
+```typescript
+export interface OpsOsMetrics 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [distro](./kibana-plugin-server.opsosmetrics.distro.md) | <code>string</code> | The os distrib. Only present for linux platforms |
+|  [distroRelease](./kibana-plugin-server.opsosmetrics.distrorelease.md) | <code>string</code> | The os distrib release, prefixed by the os distrib. Only present for linux platforms |
+|  [load](./kibana-plugin-server.opsosmetrics.load.md) | <code>{</code><br/><code>        '1m': number;</code><br/><code>        '5m': number;</code><br/><code>        '15m': number;</code><br/><code>    }</code> | cpu load metrics |
+|  [memory](./kibana-plugin-server.opsosmetrics.memory.md) | <code>{</code><br/><code>        total_in_bytes: number;</code><br/><code>        free_in_bytes: number;</code><br/><code>        used_in_bytes: number;</code><br/><code>    }</code> | system memory usage metrics |
+|  [platform](./kibana-plugin-server.opsosmetrics.platform.md) | <code>NodeJS.Platform</code> | The os platform |
+|  [platformRelease](./kibana-plugin-server.opsosmetrics.platformrelease.md) | <code>string</code> | The os platform release, prefixed by the platform name |
+|  [uptime\_in\_millis](./kibana-plugin-server.opsosmetrics.uptime_in_millis.md) | <code>number</code> | the OS uptime |
+

docs/development/core/server/kibana-plugin-server.opsosmetrics.memory.md

@@ -0,0 +1,17 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [memory](./kibana-plugin-server.opsosmetrics.memory.md)
+
+## OpsOsMetrics.memory property
+
+system memory usage metrics
+
+<b>Signature:</b>
+
+```typescript
+memory: {
+        total_in_bytes: number;
+        free_in_bytes: number;
+        used_in_bytes: number;
+    };
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.platform.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [platform](./kibana-plugin-server.opsosmetrics.platform.md)
+
+## OpsOsMetrics.platform property
+
+The os platform
+
+<b>Signature:</b>
+
+```typescript
+platform: NodeJS.Platform;
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.platformrelease.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [platformRelease](./kibana-plugin-server.opsosmetrics.platformrelease.md)
+
+## OpsOsMetrics.platformRelease property
+
+The os platform release, prefixed by the platform name
+
+<b>Signature:</b>
+
+```typescript
+platformRelease: string;
+```

docs/development/core/server/kibana-plugin-server.opsosmetrics.uptime_in_millis.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsOsMetrics](./kibana-plugin-server.opsosmetrics.md) &gt; [uptime\_in\_millis](./kibana-plugin-server.opsosmetrics.uptime_in_millis.md)
+
+## OpsOsMetrics.uptime\_in\_millis property
+
+the OS uptime
+
+<b>Signature:</b>
+
+```typescript
+uptime_in_millis: number;
+```

docs/development/core/server/kibana-plugin-server.opsprocessmetrics.event_loop_delay.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md) &gt; [event\_loop\_delay](./kibana-plugin-server.opsprocessmetrics.event_loop_delay.md)
+
+## OpsProcessMetrics.event\_loop\_delay property
+
+node event loop delay
+
+<b>Signature:</b>
+
+```typescript
+event_loop_delay: number;
+```

docs/development/core/server/kibana-plugin-server.opsprocessmetrics.md

@@ -0,0 +1,23 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md)
+
+## OpsProcessMetrics interface
+
+Process related metrics
+
+<b>Signature:</b>
+
+```typescript
+export interface OpsProcessMetrics 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [event\_loop\_delay](./kibana-plugin-server.opsprocessmetrics.event_loop_delay.md) | <code>number</code> | node event loop delay |
+|  [memory](./kibana-plugin-server.opsprocessmetrics.memory.md) | <code>{</code><br/><code>        heap: {</code><br/><code>            total_in_bytes: number;</code><br/><code>            used_in_bytes: number;</code><br/><code>            size_limit: number;</code><br/><code>        };</code><br/><code>        resident_set_size_in_bytes: number;</code><br/><code>    }</code> | process memory usage |
+|  [pid](./kibana-plugin-server.opsprocessmetrics.pid.md) | <code>number</code> | pid of the kibana process |
+|  [uptime\_in\_millis](./kibana-plugin-server.opsprocessmetrics.uptime_in_millis.md) | <code>number</code> | uptime of the kibana process |
+

docs/development/core/server/kibana-plugin-server.opsprocessmetrics.memory.md

@@ -0,0 +1,20 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md) &gt; [memory](./kibana-plugin-server.opsprocessmetrics.memory.md)
+
+## OpsProcessMetrics.memory property
+
+process memory usage
+
+<b>Signature:</b>
+
+```typescript
+memory: {
+        heap: {
+            total_in_bytes: number;
+            used_in_bytes: number;
+            size_limit: number;
+        };
+        resident_set_size_in_bytes: number;
+    };
+```

docs/development/core/server/kibana-plugin-server.opsprocessmetrics.pid.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md) &gt; [pid](./kibana-plugin-server.opsprocessmetrics.pid.md)
+
+## OpsProcessMetrics.pid property
+
+pid of the kibana process
+
+<b>Signature:</b>
+
+```typescript
+pid: number;
+```

docs/development/core/server/kibana-plugin-server.opsprocessmetrics.uptime_in_millis.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsProcessMetrics](./kibana-plugin-server.opsprocessmetrics.md) &gt; [uptime\_in\_millis](./kibana-plugin-server.opsprocessmetrics.uptime_in_millis.md)
+
+## OpsProcessMetrics.uptime\_in\_millis property
+
+uptime of the kibana process
+
+<b>Signature:</b>
+
+```typescript
+uptime_in_millis: number;
+```

docs/development/core/server/kibana-plugin-server.opsservermetrics.concurrent_connections.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsServerMetrics](./kibana-plugin-server.opsservermetrics.md) &gt; [concurrent\_connections](./kibana-plugin-server.opsservermetrics.concurrent_connections.md)
+
+## OpsServerMetrics.concurrent\_connections property
+
+number of current concurrent connections to the server
+
+<b>Signature:</b>
+
+```typescript
+concurrent_connections: number;
+```

docs/development/core/server/kibana-plugin-server.opsservermetrics.md

@@ -0,0 +1,22 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsServerMetrics](./kibana-plugin-server.opsservermetrics.md)
+
+## OpsServerMetrics interface
+
+server related metrics
+
+<b>Signature:</b>
+
+```typescript
+export interface OpsServerMetrics 
+```
+
+## Properties
+
+|  Property | Type | Description |
+|  --- | --- | --- |
+|  [concurrent\_connections](./kibana-plugin-server.opsservermetrics.concurrent_connections.md) | <code>number</code> | number of current concurrent connections to the server |
+|  [requests](./kibana-plugin-server.opsservermetrics.requests.md) | <code>{</code><br/><code>        disconnects: number;</code><br/><code>        total: number;</code><br/><code>        statusCodes: Record&lt;number, number&gt;;</code><br/><code>    }</code> | server requests stats |
+|  [response\_times](./kibana-plugin-server.opsservermetrics.response_times.md) | <code>{</code><br/><code>        avg_in_millis: number;</code><br/><code>        max_in_millis: number;</code><br/><code>    }</code> | server response time stats |
+

docs/development/core/server/kibana-plugin-server.opsservermetrics.requests.md

@@ -0,0 +1,17 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsServerMetrics](./kibana-plugin-server.opsservermetrics.md) &gt; [requests](./kibana-plugin-server.opsservermetrics.requests.md)
+
+## OpsServerMetrics.requests property
+
+server requests stats
+
+<b>Signature:</b>
+
+```typescript
+requests: {
+        disconnects: number;
+        total: number;
+        statusCodes: Record<number, number>;
+    };
+```

docs/development/core/server/kibana-plugin-server.opsservermetrics.response_times.md

@@ -0,0 +1,16 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-server](./kibana-plugin-server.md) &gt; [OpsServerMetrics](./kibana-plugin-server.opsservermetrics.md) &gt; [response\_times](./kibana-plugin-server.opsservermetrics.response_times.md)
+
+## OpsServerMetrics.response\_times property
+
+server response time stats
+
+<b>Signature:</b>
+
+```typescript
+response_times: {
+        avg_in_millis: number;
+        max_in_millis: number;
+    };
+```

package.json

@@ -326,6 +326,7 @@
     "@types/fetch-mock": "^7.3.1",
     "@types/flot": "^0.0.31",
     "@types/getopts": "^2.0.1",
+    "@types/getos": "^3.0.0",
     "@types/glob": "^7.1.1",
     "@types/globby": "^8.0.0",
     "@types/hapi": "^17.0.18",

src/core/server/index.ts

@@ -245,6 +245,14 @@ export {
   StringValidationRegexString,
 } from './ui_settings';
 
+export {
+  OpsMetrics,
+  OpsOsMetrics,
+  OpsServerMetrics,
+  OpsProcessMetrics,
+  MetricsServiceSetup,
+} from './metrics';
+
 export { RecursiveReadonly } from '../utils';
 
 export {

src/core/server/internal_types.ts

@@ -30,6 +30,7 @@ import {
 } from './saved_objects';
 import { InternalUiSettingsServiceSetup, InternalUiSettingsServiceStart } from './ui_settings';
 import { UuidServiceSetup } from './uuid';
+import { InternalMetricsServiceSetup } from './metrics';
 
 /** @internal */
 export interface InternalCoreSetup {
@@ -40,6 +41,7 @@ export interface InternalCoreSetup {
   uiSettings: InternalUiSettingsServiceSetup;
   savedObjects: InternalSavedObjectsServiceSetup;
   uuid: UuidServiceSetup;
+  metrics: InternalMetricsServiceSetup;
 }
 
 /**

src/core/server/legacy/legacy_service.test.ts

@@ -43,6 +43,7 @@ import { savedObjectsServiceMock } from '../saved_objects/saved_objects_service.
 import { capabilitiesServiceMock } from '../capabilities/capabilities_service.mock';
 import { setupMock as renderingServiceMock } from '../rendering/__mocks__/rendering_service';
 import { uuidServiceMock } from '../uuid/uuid_service.mock';
+import { metricsServiceMock } from '../metrics/metrics_service.mock';
 import { findLegacyPluginSpecs } from './plugins';
 import { LegacyVars, LegacyServiceSetupDeps, LegacyServiceStartDeps } from './types';
 import { LegacyService } from './legacy_service';
@@ -93,6 +94,7 @@ beforeEach(() => {
         },
       },
       rendering: renderingServiceMock,
+      metrics: metricsServiceMock.createInternalSetupContract(),
       uuid: uuidSetup,
     },
     plugins: { 'plugin-id': 'plugin-value' },

src/core/server/metrics/collectors/index.ts

@@ -0,0 +1,23 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export { OpsProcessMetrics, OpsOsMetrics, OpsServerMetrics, MetricsCollector } from './types';
+export { OsMetricsCollector } from './os';
+export { ProcessMetricsCollector } from './process';
+export { ServerMetricsCollector } from './server';

src/core/server/metrics/collectors/os.test.ts

@@ -0,0 +1,99 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+jest.mock('getos', () => (cb: Function) => cb(null, { dist: 'distrib', release: 'release' }));
+
+import os from 'os';
+import { OsMetricsCollector } from './os';
+
+describe('OsMetricsCollector', () => {
+  let collector: OsMetricsCollector;
+
+  beforeEach(() => {
+    collector = new OsMetricsCollector();
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it('collects platform info from the os package', async () => {
+    const platform = 'darwin';
+    const release = '10.14.1';
+
+    jest.spyOn(os, 'platform').mockImplementation(() => platform);
+    jest.spyOn(os, 'release').mockImplementation(() => release);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.platform).toBe(platform);
+    expect(metrics.platformRelease).toBe(`${platform}-${release}`);
+  });
+
+  it('collects distribution info when platform is linux', async () => {
+    const platform = 'linux';
+
+    jest.spyOn(os, 'platform').mockImplementation(() => platform);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.distro).toBe('distrib');
+    expect(metrics.distroRelease).toBe('distrib-release');
+  });
+
+  it('collects memory info from the os package', async () => {
+    const totalMemory = 1457886;
+    const freeMemory = 456786;
+
+    jest.spyOn(os, 'totalmem').mockImplementation(() => totalMemory);
+    jest.spyOn(os, 'freemem').mockImplementation(() => freeMemory);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.memory.total_in_bytes).toBe(totalMemory);
+    expect(metrics.memory.free_in_bytes).toBe(freeMemory);
+    expect(metrics.memory.used_in_bytes).toBe(totalMemory - freeMemory);
+  });
+
+  it('collects uptime info from the os package', async () => {
+    const uptime = 325;
+
+    jest.spyOn(os, 'uptime').mockImplementation(() => uptime);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.uptime_in_millis).toBe(uptime * 1000);
+  });
+
+  it('collects load info from the os package', async () => {
+    const oneMinLoad = 1;
+    const fiveMinLoad = 2;
+    const fifteenMinLoad = 3;
+
+    jest.spyOn(os, 'loadavg').mockImplementation(() => [oneMinLoad, fiveMinLoad, fifteenMinLoad]);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.load).toEqual({
+      '1m': oneMinLoad,
+      '5m': fiveMinLoad,
+      '15m': fifteenMinLoad,
+    });
+  });
+});

src/core/server/metrics/collectors/os.ts

@@ -0,0 +1,60 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import os from 'os';
+import getosAsync, { LinuxOs } from 'getos';
+import { promisify } from 'util';
+import { OpsOsMetrics, MetricsCollector } from './types';
+
+const getos = promisify(getosAsync);
+
+export class OsMetricsCollector implements MetricsCollector<OpsOsMetrics> {
+  public async collect(): Promise<OpsOsMetrics> {
+    const platform = os.platform();
+    const load = os.loadavg();
+
+    const metrics: OpsOsMetrics = {
+      platform,
+      platformRelease: `${platform}-${os.release()}`,
+      load: {
+        '1m': load[0],
+        '5m': load[1],
+        '15m': load[2],
+      },
+      memory: {
+        total_in_bytes: os.totalmem(),
+        free_in_bytes: os.freemem(),
+        used_in_bytes: os.totalmem() - os.freemem(),
+      },
+      uptime_in_millis: os.uptime() * 1000,
+    };
+
+    if (platform === 'linux') {
+      try {
+        const distro = (await getos()) as LinuxOs;
+        metrics.distro = distro.dist;
+        metrics.distroRelease = `${distro.dist}-${distro.release}`;
+      } catch (e) {
+        // ignore errors
+      }
+    }
+
+    return metrics;
+  }
+}

src/core/server/metrics/collectors/process.test.ts

@@ -0,0 +1,81 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import v8, { HeapInfo } from 'v8';
+import { ProcessMetricsCollector } from './process';
+
+describe('ProcessMetricsCollector', () => {
+  let collector: ProcessMetricsCollector;
+
+  beforeEach(() => {
+    collector = new ProcessMetricsCollector();
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it('collects pid from the process', async () => {
+    const metrics = await collector.collect();
+
+    expect(metrics.pid).toEqual(process.pid);
+  });
+
+  it('collects event loop delay', async () => {
+    const metrics = await collector.collect();
+
+    expect(metrics.event_loop_delay).toBeGreaterThan(0);
+  });
+
+  it('collects uptime info from the process', async () => {
+    const uptime = 58986;
+    jest.spyOn(process, 'uptime').mockImplementation(() => uptime);
+
+    const metrics = await collector.collect();
+
+    expect(metrics.uptime_in_millis).toEqual(uptime * 1000);
+  });
+
+  it('collects memory info from the process', async () => {
+    const heapTotal = 58986;
+    const heapUsed = 4688;
+    const heapSizeLimit = 5788;
+    const rss = 5865;
+    jest.spyOn(process, 'memoryUsage').mockImplementation(() => ({
+      rss,
+      heapTotal,
+      heapUsed,
+      external: 0,
+    }));
+
+    jest.spyOn(v8, 'getHeapStatistics').mockImplementation(
+      () =>
+        ({
+          heap_size_limit: heapSizeLimit,
+        } as HeapInfo)
+    );
+
+    const metrics = await collector.collect();
+
+    expect(metrics.memory.heap.total_in_bytes).toEqual(heapTotal);
+    expect(metrics.memory.heap.used_in_bytes).toEqual(heapUsed);
+    expect(metrics.memory.heap.size_limit).toEqual(heapSizeLimit);
+    expect(metrics.memory.resident_set_size_in_bytes).toEqual(rss);
+  });
+});

src/core/server/metrics/collectors/process.ts

@@ -0,0 +1,52 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import v8 from 'v8';
+import { Bench } from 'hoek';
+import { OpsProcessMetrics, MetricsCollector } from './types';
+
+export class ProcessMetricsCollector implements MetricsCollector<OpsProcessMetrics> {
+  public async collect(): Promise<OpsProcessMetrics> {
+    const heapStats = v8.getHeapStatistics();
+    const memoryUsage = process.memoryUsage();
+    const [eventLoopDelay] = await Promise.all([getEventLoopDelay()]);
+    return {
+      memory: {
+        heap: {
+          total_in_bytes: memoryUsage.heapTotal,
+          used_in_bytes: memoryUsage.heapUsed,
+          size_limit: heapStats.heap_size_limit,
+        },
+        resident_set_size_in_bytes: memoryUsage.rss,
+      },
+      pid: process.pid,
+      event_loop_delay: eventLoopDelay,
+      uptime_in_millis: process.uptime() * 1000,
+    };
+  }
+}
+
+const getEventLoopDelay = (): Promise<number> => {
+  const bench = new Bench();
+  return new Promise(resolve => {
+    setImmediate(() => {
+      return resolve(bench.elapsed());
+    });
+  });
+};

src/core/server/metrics/collectors/server.ts

@@ -0,0 +1,80 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import { ResponseObject, Server as HapiServer } from 'hapi';
+import { OpsServerMetrics, MetricsCollector } from './types';
+
+interface ServerResponseTime {
+  count: number;
+  total: number;
+  max: number;
+}
+
+export class ServerMetricsCollector implements MetricsCollector<OpsServerMetrics> {
+  private readonly requests: OpsServerMetrics['requests'] = {
+    disconnects: 0,
+    total: 0,
+    statusCodes: {},
+  };
+  private readonly responseTimes: ServerResponseTime = {
+    count: 0,
+    total: 0,
+    max: 0,
+  };
+
+  constructor(private readonly server: HapiServer) {
+    this.server.ext('onRequest', (request, h) => {
+      this.requests.total++;
+      request.events.once('disconnect', () => {
+        this.requests.disconnects++;
+      });
+      return h.continue;
+    });
+    this.server.events.on('response', request => {
+      const statusCode = (request.response as ResponseObject)?.statusCode;
+      if (statusCode) {
+        if (!this.requests.statusCodes[statusCode]) {
+          this.requests.statusCodes[statusCode] = 0;
+        }
+        this.requests.statusCodes[statusCode]++;
+      }
+
+      const duration = Date.now() - request.info.received;
+      this.responseTimes.count++;
+      this.responseTimes.total += duration;
+      this.responseTimes.max = Math.max(this.responseTimes.max, duration);
+    });
+  }
+
+  public async collect(): Promise<OpsServerMetrics> {
+    const connections = await new Promise<number>(resolve => {
+      this.server.listener.getConnections((_, count) => {
+        resolve(count);
+      });
+    });
+
+    return {
+      requests: this.requests,
+      response_times: {
+        avg_in_millis: this.responseTimes.total / Math.max(this.responseTimes.count, 1),
+        max_in_millis: this.responseTimes.max,
+      },
+      concurrent_connections: connections,
+    };
+  }
+}

src/core/server/metrics/collectors/types.ts

@@ -0,0 +1,110 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/** Base interface for all metrics gatherers */
+export interface MetricsCollector<T> {
+  collect(): Promise<T>;
+}
+
+/**
+ * Process related metrics
+ * @public
+ */
+export interface OpsProcessMetrics {
+  /** process memory usage */
+  memory: {
+    /** heap memory usage */
+    heap: {
+      /** total heap available */
+      total_in_bytes: number;
+      /** used heap */
+      used_in_bytes: number;
+      /** v8 heap size limit */
+      size_limit: number;
+    };
+    /** node rss */
+    resident_set_size_in_bytes: number;
+  };
+  /** node event loop delay */
+  event_loop_delay: number;
+  /** pid of the kibana process */
+  pid: number;
+  /** uptime of the kibana process */
+  uptime_in_millis: number;
+}
+
+/**
+ * OS related metrics
+ * @public
+ */
+export interface OpsOsMetrics {
+  /** The os platform */
+  platform: NodeJS.Platform;
+  /** The os platform release, prefixed by the platform name */
+  platformRelease: string;
+  /** The os distrib. Only present for linux platforms */
+  distro?: string;
+  /** The os distrib release, prefixed by the os distrib. Only present for linux platforms */
+  distroRelease?: string;
+  /** cpu load metrics */
+  load: {
+    /** load for last minute */
+    '1m': number;
+    /** load for last 5 minutes */
+    '5m': number;
+    /** load for last 15 minutes */
+    '15m': number;
+  };
+  /** system memory usage metrics */
+  memory: {
+    /** total memory available */
+    total_in_bytes: number;
+    /** current free memory */
+    free_in_bytes: number;
+    /** current used memory */
+    used_in_bytes: number;
+  };
+  /** the OS uptime */
+  uptime_in_millis: number;
+}
+
+/**
+ * server related metrics
+ * @public
+ */
+export interface OpsServerMetrics {
+  /** server response time stats */
+  response_times: {
+    /** average response time */
+    avg_in_millis: number;
+    /** maximum response time */
+    max_in_millis: number;
+  };
+  /** server requests stats */
+  requests: {
+    /** number of disconnected requests since startup */
+    disconnects: number;
+    /** total number of requests handled since startup */
+    total: number;
+    /** number of request handled per response status code */
+    statusCodes: Record<number, number>;
+  };
+  /** number of current concurrent connections to the server */
+  concurrent_connections: number;
+}

src/core/server/metrics/index.ts

@@ -0,0 +1,29 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export {
+  InternalMetricsServiceStart,
+  InternalMetricsServiceSetup,
+  MetricsServiceSetup,
+  MetricsServiceStart,
+  OpsMetrics,
+} from './types';
+export { OpsProcessMetrics, OpsServerMetrics, OpsOsMetrics } from './collectors';
+export { MetricsService } from './metrics_service';
+export { opsConfig } from './ops_config';

src/core/server/metrics/integration_tests/server_collector.test.ts

@@ -0,0 +1,183 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { Subject } from 'rxjs';
+import { take } from 'rxjs/operators';
+import supertest from 'supertest';
+import { Server as HapiServer } from 'hapi';
+import { createHttpServer } from '../../http/test_utils';
+import { HttpService, IRouter } from '../../http';
+import { contextServiceMock } from '../../context/context_service.mock';
+import { ServerMetricsCollector } from '../collectors/server';
+
+describe('ServerMetricsCollector', () => {
+  let server: HttpService;
+  let collector: ServerMetricsCollector;
+  let hapiServer: HapiServer;
+  let router: IRouter;
+
+  const delay = (ms: number) => new Promise(resolve => setTimeout(resolve, ms));
+  const sendGet = (path: string) => supertest(hapiServer.listener).get(path);
+
+  beforeEach(async () => {
+    server = createHttpServer();
+    const contextSetup = contextServiceMock.createSetupContract();
+    const httpSetup = await server.setup({ context: contextSetup });
+    hapiServer = httpSetup.server;
+    router = httpSetup.createRouter('/');
+    collector = new ServerMetricsCollector(hapiServer);
+  });
+
+  afterEach(async () => {
+    await server.stop();
+  });
+
+  it('collect requests infos', async () => {
+    router.get({ path: '/', validate: false }, async (ctx, req, res) => {
+      return res.ok({ body: '' });
+    });
+    await server.start();
+
+    let metrics = await collector.collect();
+
+    expect(metrics.requests).toEqual({
+      total: 0,
+      disconnects: 0,
+      statusCodes: {},
+    });
+
+    await sendGet('/');
+    await sendGet('/');
+    await sendGet('/not-found');
+
+    metrics = await collector.collect();
+
+    expect(metrics.requests).toEqual({
+      total: 3,
+      disconnects: 0,
+      statusCodes: {
+        '200': 2,
+        '404': 1,
+      },
+    });
+  });
+
+  it('collect disconnects requests infos', async () => {
+    const never = new Promise(resolve => undefined);
+
+    router.get({ path: '/', validate: false }, async (ctx, req, res) => {
+      return res.ok({ body: '' });
+    });
+    router.get({ path: '/disconnect', validate: false }, async (ctx, req, res) => {
+      await never;
+      return res.ok({ body: '' });
+    });
+    await server.start();
+
+    await sendGet('/');
+    const discoReq1 = sendGet('/disconnect').end();
+    const discoReq2 = sendGet('/disconnect').end();
+    await delay(20);
+
+    let metrics = await collector.collect();
+    expect(metrics.requests).toEqual(
+      expect.objectContaining({
+        total: 3,
+        disconnects: 0,
+      })
+    );
+
+    discoReq1.abort();
+    await delay(20);
+
+    metrics = await collector.collect();
+    expect(metrics.requests).toEqual(
+      expect.objectContaining({
+        total: 3,
+        disconnects: 1,
+      })
+    );
+
+    discoReq2.abort();
+    await delay(20);
+
+    metrics = await collector.collect();
+    expect(metrics.requests).toEqual(
+      expect.objectContaining({
+        total: 3,
+        disconnects: 2,
+      })
+    );
+  });
+
+  it('collect response times', async () => {
+    router.get({ path: '/no-delay', validate: false }, async (ctx, req, res) => {
+      return res.ok({ body: '' });
+    });
+    router.get({ path: '/500-ms', validate: false }, async (ctx, req, res) => {
+      await delay(500);
+      return res.ok({ body: '' });
+    });
+    router.get({ path: '/250-ms', validate: false }, async (ctx, req, res) => {
+      await delay(250);
+      return res.ok({ body: '' });
+    });
+    await server.start();
+
+    await Promise.all([sendGet('/no-delay'), sendGet('/250-ms')]);
+    let metrics = await collector.collect();
+
+    expect(metrics.response_times.avg_in_millis).toBeGreaterThanOrEqual(125);
+    expect(metrics.response_times.max_in_millis).toBeGreaterThanOrEqual(250);
+
+    await Promise.all([sendGet('/500-ms'), sendGet('/500-ms')]);
+    metrics = await collector.collect();
+
+    expect(metrics.response_times.avg_in_millis).toBeGreaterThanOrEqual(250);
+    expect(metrics.response_times.max_in_millis).toBeGreaterThanOrEqual(500);
+  });
+
+  it('collect connection count', async () => {
+    const waitSubject = new Subject();
+
+    router.get({ path: '/', validate: false }, async (ctx, req, res) => {
+      await waitSubject.pipe(take(1)).toPromise();
+      return res.ok({ body: '' });
+    });
+    await server.start();
+
+    let metrics = await collector.collect();
+    expect(metrics.concurrent_connections).toEqual(0);
+
+    sendGet('/').end(() => null);
+    await delay(20);
+    metrics = await collector.collect();
+    expect(metrics.concurrent_connections).toEqual(1);
+
+    sendGet('/').end(() => null);
+    await delay(20);
+    metrics = await collector.collect();
+    expect(metrics.concurrent_connections).toEqual(2);
+
+    waitSubject.next('go');
+    await delay(20);
+    metrics = await collector.collect();
+    expect(metrics.concurrent_connections).toEqual(0);
+  });
+});

src/core/server/metrics/metrics_service.mock.ts

@@ -0,0 +1,67 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { MetricsService } from './metrics_service';
+import {
+  InternalMetricsServiceSetup,
+  InternalMetricsServiceStart,
+  MetricsServiceSetup,
+  MetricsServiceStart,
+} from './types';
+
+const createSetupContractMock = () => {
+  const setupContract: jest.Mocked<MetricsServiceSetup> = {
+    getOpsMetrics$: jest.fn(),
+  };
+  return setupContract;
+};
+
+const createInternalSetupContractMock = () => {
+  const setupContract: jest.Mocked<InternalMetricsServiceSetup> = createSetupContractMock();
+  return setupContract;
+};
+
+const createStartContractMock = () => {
+  const startContract: jest.Mocked<MetricsServiceStart> = {};
+  return startContract;
+};
+
+const createInternalStartContractMock = () => {
+  const startContract: jest.Mocked<InternalMetricsServiceStart> = createStartContractMock();
+  return startContract;
+};
+
+type MetricsServiceContract = PublicMethodsOf<MetricsService>;
+
+const createMock = () => {
+  const mocked: jest.Mocked<MetricsServiceContract> = {
+    setup: jest.fn().mockReturnValue(createInternalSetupContractMock()),
+    start: jest.fn().mockReturnValue(createInternalStartContractMock()),
+    stop: jest.fn(),
+  };
+  return mocked;
+};
+
+export const metricsServiceMock = {
+  create: createMock,
+  createSetupContract: createSetupContractMock,
+  createStartContract: createStartContractMock,
+  createInternalSetupContract: createInternalSetupContractMock,
+  createInternalStartContract: createInternalStartContractMock,
+};

src/core/server/metrics/metrics_service.test.mocks.ts

@@ -0,0 +1,25 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export const mockOpsCollector = {
+  collect: jest.fn(),
+};
+jest.doMock('./ops_metrics_collector', () => ({
+  OpsMetricsCollector: jest.fn().mockImplementation(() => mockOpsCollector),
+}));

src/core/server/metrics/metrics_service.test.ts

@@ -0,0 +1,134 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import moment from 'moment';
+import { mockOpsCollector } from './metrics_service.test.mocks';
+import { MetricsService } from './metrics_service';
+import { mockCoreContext } from '../core_context.mock';
+import { configServiceMock } from '../config/config_service.mock';
+import { httpServiceMock } from '../http/http_service.mock';
+import { take } from 'rxjs/operators';
+
+const testInterval = 100;
+
+const dummyMetrics = { metricA: 'value', metricB: 'otherValue' };
+
+describe('MetricsService', () => {
+  const httpMock = httpServiceMock.createSetupContract();
+  let metricsService: MetricsService;
+
+  beforeEach(() => {
+    jest.useFakeTimers();
+
+    const configService = configServiceMock.create({
+      atPath: { interval: moment.duration(testInterval) },
+    });
+    const coreContext = mockCoreContext.create({ configService });
+    metricsService = new MetricsService(coreContext);
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    jest.clearAllTimers();
+  });
+
+  describe('#start', () => {
+    it('invokes setInterval with the configured interval', async () => {
+      await metricsService.setup({ http: httpMock });
+      await metricsService.start();
+
+      expect(setInterval).toHaveBeenCalledTimes(1);
+      expect(setInterval).toHaveBeenCalledWith(expect.any(Function), testInterval);
+    });
+
+    it('emits the metrics at start', async () => {
+      mockOpsCollector.collect.mockResolvedValue(dummyMetrics);
+
+      const { getOpsMetrics$ } = await metricsService.setup({
+        http: httpMock,
+      });
+
+      await metricsService.start();
+
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(1);
+      expect(
+        await getOpsMetrics$()
+          .pipe(take(1))
+          .toPromise()
+      ).toEqual(dummyMetrics);
+    });
+
+    it('collects the metrics at every interval', async () => {
+      mockOpsCollector.collect.mockResolvedValue(dummyMetrics);
+
+      await metricsService.setup({ http: httpMock });
+
+      await metricsService.start();
+
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(1);
+
+      jest.advanceTimersByTime(testInterval);
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(2);
+
+      jest.advanceTimersByTime(testInterval);
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(3);
+    });
+
+    it('throws when called before setup', async () => {
+      await expect(metricsService.start()).rejects.toThrowErrorMatchingInlineSnapshot(
+        `"#setup() needs to be run first"`
+      );
+    });
+  });
+
+  describe('#stop', () => {
+    it('stops the metrics interval', async () => {
+      const { getOpsMetrics$ } = await metricsService.setup({ http: httpMock });
+      await metricsService.start();
+
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(1);
+
+      jest.advanceTimersByTime(testInterval);
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(2);
+
+      await metricsService.stop();
+      jest.advanceTimersByTime(10 * testInterval);
+      expect(mockOpsCollector.collect).toHaveBeenCalledTimes(2);
+
+      getOpsMetrics$().subscribe({ complete: () => {} });
+    });
+
+    it('completes the metrics observable', async () => {
+      const { getOpsMetrics$ } = await metricsService.setup({ http: httpMock });
+      await metricsService.start();
+
+      let completed = false;
+
+      getOpsMetrics$().subscribe({
+        complete: () => {
+          completed = true;
+        },
+      });
+
+      await metricsService.stop();
+
+      expect(completed).toEqual(true);
+    });
+  });
+});

src/core/server/metrics/metrics_service.ts

@@ -0,0 +1,86 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { ReplaySubject } from 'rxjs';
+import { first, shareReplay } from 'rxjs/operators';
+import { CoreService } from '../../types';
+import { CoreContext } from '../core_context';
+import { Logger } from '../logging';
+import { InternalHttpServiceSetup } from '../http';
+import { InternalMetricsServiceSetup, InternalMetricsServiceStart, OpsMetrics } from './types';
+import { OpsMetricsCollector } from './ops_metrics_collector';
+import { opsConfig, OpsConfigType } from './ops_config';
+
+interface MetricsServiceSetupDeps {
+  http: InternalHttpServiceSetup;
+}
+
+/** @internal */
+export class MetricsService
+  implements CoreService<InternalMetricsServiceSetup, InternalMetricsServiceStart> {
+  private readonly logger: Logger;
+  private metricsCollector?: OpsMetricsCollector;
+  private collectInterval?: NodeJS.Timeout;
+  private metrics$ = new ReplaySubject<OpsMetrics>(1);
+
+  constructor(private readonly coreContext: CoreContext) {
+    this.logger = coreContext.logger.get('metrics');
+  }
+
+  public async setup({ http }: MetricsServiceSetupDeps): Promise<InternalMetricsServiceSetup> {
+    this.metricsCollector = new OpsMetricsCollector(http.server);
+
+    const metricsObservable = this.metrics$.pipe(shareReplay(1));
+
+    return {
+      getOpsMetrics$: () => metricsObservable,
+    };
+  }
+
+  public async start(): Promise<InternalMetricsServiceStart> {
+    if (!this.metricsCollector) {
+      throw new Error('#setup() needs to be run first');
+    }
+    const config = await this.coreContext.configService
+      .atPath<OpsConfigType>(opsConfig.path)
+      .pipe(first())
+      .toPromise();
+
+    await this.refreshMetrics();
+
+    this.collectInterval = setInterval(() => {
+      this.refreshMetrics();
+    }, config.interval.asMilliseconds());
+
+    return {};
+  }
+
+  private async refreshMetrics() {
+    this.logger.debug('Refreshing metrics');
+    const metrics = await this.metricsCollector!.collect();
+    this.metrics$.next(metrics);
+  }
+
+  public async stop() {
+    if (this.collectInterval) {
+      clearInterval(this.collectInterval);
+    }
+    this.metrics$.complete();
+  }
+}

src/core/server/metrics/ops_config.ts

@@ -0,0 +1,29 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { schema, TypeOf } from '@kbn/config-schema';
+
+export const opsConfig = {
+  path: 'ops',
+  schema: schema.object({
+    interval: schema.duration({ defaultValue: '5s' }),
+  }),
+};
+
+export type OpsConfigType = TypeOf<typeof opsConfig.schema>;

src/core/server/metrics/ops_metrics_collector.test.mocks.ts

@@ -0,0 +1,39 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export const mockOsCollector = {
+  collect: jest.fn(),
+};
+jest.doMock('./collectors/os', () => ({
+  OsMetricsCollector: jest.fn().mockImplementation(() => mockOsCollector),
+}));
+
+export const mockProcessCollector = {
+  collect: jest.fn(),
+};
+jest.doMock('./collectors/process', () => ({
+  ProcessMetricsCollector: jest.fn().mockImplementation(() => mockProcessCollector),
+}));
+
+export const mockServerCollector = {
+  collect: jest.fn(),
+};
+jest.doMock('./collectors/server', () => ({
+  ServerMetricsCollector: jest.fn().mockImplementation(() => mockServerCollector),
+}));

src/core/server/metrics/ops_metrics_collector.test.ts

@@ -0,0 +1,59 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import {
+  mockOsCollector,
+  mockProcessCollector,
+  mockServerCollector,
+} from './ops_metrics_collector.test.mocks';
+import { httpServiceMock } from '../http/http_service.mock';
+import { OpsMetricsCollector } from './ops_metrics_collector';
+
+describe('OpsMetricsCollector', () => {
+  let collector: OpsMetricsCollector;
+
+  beforeEach(() => {
+    const hapiServer = httpServiceMock.createSetupContract().server;
+    collector = new OpsMetricsCollector(hapiServer);
+
+    mockOsCollector.collect.mockResolvedValue('osMetrics');
+  });
+
+  it('gathers metrics from the underlying collectors', async () => {
+    mockOsCollector.collect.mockResolvedValue('osMetrics');
+    mockProcessCollector.collect.mockResolvedValue('processMetrics');
+    mockServerCollector.collect.mockResolvedValue({
+      requests: 'serverRequestsMetrics',
+      response_times: 'serverTimingMetrics',
+    });
+
+    const metrics = await collector.collect();
+
+    expect(mockOsCollector.collect).toHaveBeenCalledTimes(1);
+    expect(mockProcessCollector.collect).toHaveBeenCalledTimes(1);
+    expect(mockServerCollector.collect).toHaveBeenCalledTimes(1);
+
+    expect(metrics).toEqual({
+      process: 'processMetrics',
+      os: 'osMetrics',
+      requests: 'serverRequestsMetrics',
+      response_times: 'serverTimingMetrics',
+    });
+  });
+});

src/core/server/metrics/ops_metrics_collector.ts

@@ -0,0 +1,52 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { Server as HapiServer } from 'hapi';
+import {
+  ProcessMetricsCollector,
+  OsMetricsCollector,
+  ServerMetricsCollector,
+  MetricsCollector,
+} from './collectors';
+import { OpsMetrics } from './types';
+
+export class OpsMetricsCollector implements MetricsCollector<OpsMetrics> {
+  private readonly processCollector: ProcessMetricsCollector;
+  private readonly osCollector: OsMetricsCollector;
+  private readonly serverCollector: ServerMetricsCollector;
+
+  constructor(server: HapiServer) {
+    this.processCollector = new ProcessMetricsCollector();
+    this.osCollector = new OsMetricsCollector();
+    this.serverCollector = new ServerMetricsCollector(server);
+  }
+
+  public async collect(): Promise<OpsMetrics> {
+    const [process, os, server] = await Promise.all([
+      this.processCollector.collect(),
+      this.osCollector.collect(),
+      this.serverCollector.collect(),
+    ]);
+    return {
+      process,
+      os,
+      ...server,
+    };
+  }
+}

src/core/server/metrics/types.ts

@@ -0,0 +1,66 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { Observable } from 'rxjs';
+import { OpsProcessMetrics, OpsOsMetrics, OpsServerMetrics } from './collectors';
+
+/**
+ * APIs to retrieves metrics gathered and exposed by the core platform.
+ *
+ * @public
+ */
+export interface MetricsServiceSetup {
+  /**
+   * Retrieve an observable emitting the {@link OpsMetrics} gathered.
+   * The observable will emit an initial value during core's `start` phase, and a new value every fixed interval of time,
+   * based on the `opts.interval` configuration property.
+   *
+   * @example
+   * ```ts
+   * core.metrics.getOpsMetrics$().subscribe(metrics => {
+   *   // do something with the metrics
+   * })
+   * ```
+   */
+  getOpsMetrics$: () => Observable<OpsMetrics>;
+}
+// eslint-disable-next-line @typescript-eslint/no-empty-interface
+export interface MetricsServiceStart {}
+
+export type InternalMetricsServiceSetup = MetricsServiceSetup;
+export type InternalMetricsServiceStart = MetricsServiceStart;
+
+/**
+ * Regroups metrics gathered by all the collectors.
+ * This contains metrics about the os/runtime, the kibana process and the http server.
+ *
+ * @public
+ */
+export interface OpsMetrics {
+  /** Process related metrics */
+  process: OpsProcessMetrics;
+  /** OS related metrics */
+  os: OpsOsMetrics;
+  /** server response time stats */
+  response_times: OpsServerMetrics['response_times'];
+  /** server requests stats */
+  requests: OpsServerMetrics['requests'];
+  /** number of current concurrent connections to the server */
+  concurrent_connections: OpsServerMetrics['concurrent_connections'];
+}

src/core/server/mocks.ts

@@ -30,6 +30,8 @@ import { uiSettingsServiceMock } from './ui_settings/ui_settings_service.mock';
 import { SharedGlobalConfig } from './plugins';
 import { InternalCoreSetup, InternalCoreStart } from './internal_types';
 import { capabilitiesServiceMock } from './capabilities/capabilities_service.mock';
+import { metricsServiceMock } from './metrics/metrics_service.mock';
+import { uuidServiceMock } from './uuid/uuid_service.mock';
 
 export { httpServerMock } from './http/http_server.mocks';
 export { sessionStorageMock } from './http/cookie_session_storage.mocks';
@@ -40,7 +42,7 @@ export { loggingServiceMock } from './logging/logging_service.mock';
 export { savedObjectsRepositoryMock } from './saved_objects/service/lib/repository.mock';
 export { typeRegistryMock as savedObjectsTypeRegistryMock } from './saved_objects/saved_objects_type_registry.mock';
 export { uiSettingsServiceMock } from './ui_settings/ui_settings_service.mock';
-import { uuidServiceMock } from './uuid/uuid_service.mock';
+export { metricsServiceMock } from './metrics/metrics_service.mock';
 
 export function pluginInitializerContextConfigMock<T>(config: T) {
   const globalConfig: SharedGlobalConfig = {
@@ -153,6 +155,7 @@ function createInternalCoreSetupMock() {
     uiSettings: uiSettingsServiceMock.createSetupContract(),
     savedObjects: savedObjectsServiceMock.createInternalSetupContract(),
     uuid: uuidServiceMock.createSetupContract(),
+    metrics: metricsServiceMock.createInternalSetupContract(),
   };
   return setupDeps;
 }

src/core/server/server.api.md

@@ -1176,6 +1176,11 @@ export interface LogRecord {
     timestamp: Date;
 }
 
+// @public
+export interface MetricsServiceSetup {
+    getOpsMetrics$: () => Observable<OpsMetrics>;
+}
+
 // @public (undocumented)
 export type MIGRATION_ASSISTANCE_INDEX_ACTION = 'upgrade' | 'reindex';
 
@@ -1227,6 +1232,63 @@ export interface OnPreResponseToolkit {
     next: (responseExtensions?: OnPreResponseExtensions) => OnPreResponseResult;
 }
 
+// @public
+export interface OpsMetrics {
+    concurrent_connections: OpsServerMetrics['concurrent_connections'];
+    os: OpsOsMetrics;
+    process: OpsProcessMetrics;
+    requests: OpsServerMetrics['requests'];
+    response_times: OpsServerMetrics['response_times'];
+}
+
+// @public
+export interface OpsOsMetrics {
+    distro?: string;
+    distroRelease?: string;
+    load: {
+        '1m': number;
+        '5m': number;
+        '15m': number;
+    };
+    memory: {
+        total_in_bytes: number;
+        free_in_bytes: number;
+        used_in_bytes: number;
+    };
+    platform: NodeJS.Platform;
+    platformRelease: string;
+    uptime_in_millis: number;
+}
+
+// @public
+export interface OpsProcessMetrics {
+    event_loop_delay: number;
+    memory: {
+        heap: {
+            total_in_bytes: number;
+            used_in_bytes: number;
+            size_limit: number;
+        };
+        resident_set_size_in_bytes: number;
+    };
+    pid: number;
+    uptime_in_millis: number;
+}
+
+// @public
+export interface OpsServerMetrics {
+    concurrent_connections: number;
+    requests: {
+        disconnects: number;
+        total: number;
+        statusCodes: Record<number, number>;
+    };
+    response_times: {
+        avg_in_millis: number;
+        max_in_millis: number;
+    };
+}
+
 // @public (undocumented)
 export interface PackageInfo {
     // (undocumented)

src/core/server/server.test.mocks.ts

@@ -79,3 +79,9 @@ export const mockUuidService = uuidServiceMock.create();
 jest.doMock('./uuid/uuid_service', () => ({
   UuidService: jest.fn(() => mockUuidService),
 }));
+
+import { metricsServiceMock } from './metrics/metrics_service.mock';
+export const mockMetricsService = metricsServiceMock.create();
+jest.doMock('./metrics/metrics_service', () => ({
+  MetricsService: jest.fn(() => mockMetricsService),
+}));

src/core/server/server.test.ts

@@ -28,6 +28,7 @@ import {
   mockEnsureValidConfiguration,
   mockUiSettingsService,
   mockRenderingService,
+  mockMetricsService,
 } from './server.test.mocks';
 
 import { BehaviorSubject } from 'rxjs';
@@ -61,6 +62,7 @@ test('sets up services on "setup"', async () => {
   expect(mockSavedObjectsService.setup).not.toHaveBeenCalled();
   expect(mockUiSettingsService.setup).not.toHaveBeenCalled();
   expect(mockRenderingService.setup).not.toHaveBeenCalled();
+  expect(mockMetricsService.setup).not.toHaveBeenCalled();
 
   await server.setup();
 
@@ -71,6 +73,7 @@ test('sets up services on "setup"', async () => {
   expect(mockSavedObjectsService.setup).toHaveBeenCalledTimes(1);
   expect(mockUiSettingsService.setup).toHaveBeenCalledTimes(1);
   expect(mockRenderingService.setup).toHaveBeenCalledTimes(1);
+  expect(mockMetricsService.setup).toHaveBeenCalledTimes(1);
 });
 
 test('injects legacy dependency to context#setup()', async () => {
@@ -107,6 +110,7 @@ test('runs services on "start"', async () => {
   expect(mockLegacyService.start).not.toHaveBeenCalled();
   expect(mockSavedObjectsService.start).not.toHaveBeenCalled();
   expect(mockUiSettingsService.start).not.toHaveBeenCalled();
+  expect(mockMetricsService.start).not.toHaveBeenCalled();
 
   await server.start();
 
@@ -114,6 +118,7 @@ test('runs services on "start"', async () => {
   expect(mockLegacyService.start).toHaveBeenCalledTimes(1);
   expect(mockSavedObjectsService.start).toHaveBeenCalledTimes(1);
   expect(mockUiSettingsService.start).toHaveBeenCalledTimes(1);
+  expect(mockMetricsService.start).toHaveBeenCalledTimes(1);
 });
 
 test('does not fail on "setup" if there are unused paths detected', async () => {
@@ -135,6 +140,7 @@ test('stops services on "stop"', async () => {
   expect(mockLegacyService.stop).not.toHaveBeenCalled();
   expect(mockSavedObjectsService.stop).not.toHaveBeenCalled();
   expect(mockUiSettingsService.stop).not.toHaveBeenCalled();
+  expect(mockMetricsService.stop).not.toHaveBeenCalled();
 
   await server.stop();
 
@@ -144,6 +150,7 @@ test('stops services on "stop"', async () => {
   expect(mockLegacyService.stop).toHaveBeenCalledTimes(1);
   expect(mockSavedObjectsService.stop).toHaveBeenCalledTimes(1);
   expect(mockUiSettingsService.stop).toHaveBeenCalledTimes(1);
+  expect(mockMetricsService.stop).toHaveBeenCalledTimes(1);
 });
 
 test(`doesn't setup core services if config validation fails`, async () => {
@@ -159,6 +166,7 @@ test(`doesn't setup core services if config validation fails`, async () => {
   expect(mockLegacyService.setup).not.toHaveBeenCalled();
   expect(mockUiSettingsService.setup).not.toHaveBeenCalled();
   expect(mockRenderingService.setup).not.toHaveBeenCalled();
+  expect(mockMetricsService.setup).not.toHaveBeenCalled();
 });
 
 test(`doesn't setup core services if legacy config validation fails`, async () => {
@@ -178,4 +186,5 @@ test(`doesn't setup core services if legacy config validation fails`, async () =
   expect(mockLegacyService.setup).not.toHaveBeenCalled();
   expect(mockSavedObjectsService.stop).not.toHaveBeenCalled();
   expect(mockUiSettingsService.setup).not.toHaveBeenCalled();
+  expect(mockMetricsService.setup).not.toHaveBeenCalled();
 });

src/core/server/server.ts

@@ -34,6 +34,7 @@ import { Logger, LoggerFactory } from './logging';
 import { UiSettingsService } from './ui_settings';
 import { PluginsService, config as pluginsConfig } from './plugins';
 import { SavedObjectsService } from '../server/saved_objects';
+import { MetricsService, opsConfig } from './metrics';
 
 import { config as cspConfig } from './csp';
 import { config as elasticsearchConfig } from './elasticsearch';
@@ -67,6 +68,7 @@ export class Server {
   private readonly savedObjects: SavedObjectsService;
   private readonly uiSettings: UiSettingsService;
   private readonly uuid: UuidService;
+  private readonly metrics: MetricsService;
 
   private coreStart?: InternalCoreStart;
 
@@ -89,6 +91,7 @@ export class Server {
     this.uiSettings = new UiSettingsService(core);
     this.capabilities = new CapabilitiesService(core);
     this.uuid = new UuidService(core);
+    this.metrics = new MetricsService(core);
   }
 
   public async setup() {
@@ -137,6 +140,8 @@ export class Server {
       legacyPlugins,
     });
 
+    const metricsSetup = await this.metrics.setup({ http: httpSetup });
+
     const coreSetup: InternalCoreSetup = {
       capabilities: capabilitiesSetup,
       context: contextServiceSetup,
@@ -145,6 +150,7 @@ export class Server {
       uiSettings: uiSettingsSetup,
       savedObjects: savedObjectsSetup,
       uuid: uuidSetup,
+      metrics: metricsSetup,
     };
 
     const pluginsSetup = await this.plugins.setup(coreSetup);
@@ -193,6 +199,7 @@ export class Server {
 
     await this.http.start();
     await this.rendering.start();
+    await this.metrics.start();
 
     return this.coreStart;
   }
@@ -207,6 +214,7 @@ export class Server {
     await this.http.stop();
     await this.uiSettings.stop();
     await this.rendering.stop();
+    await this.metrics.stop();
   }
 
   private registerDefaultRoute(httpSetup: InternalHttpServiceSetup) {
@@ -260,6 +268,7 @@ export class Server {
       [savedObjectsConfig.path, savedObjectsConfig.schema],
       [savedObjectsMigrationConfig.path, savedObjectsMigrationConfig.schema],
       [uiSettingsConfig.path, uiSettingsConfig.schema],
+      [opsConfig.path, opsConfig.schema],
     ];
 
     this.configService.addDeprecationProvider(rootConfigPath, coreDeprecationProvider);