# Hawkular Metrics

This project is an implementation of the Vert.x Metrics Service Provider Interface (SPI): metrics built from Vert.x events will be sent to Hawkular, an open source monitoring and management solution.

## Features

- Vert.x core tools monitoring: TCP/HTTP client and servers, `DatagramSocket`, `EventBus` and handlers

- User defined metrics via an `EventBus` bridge.

## Getting started

The vertx-hawkular-metrics module must be present in the classpath.

Maven users should add this to their project POM file:

    <dependency>
      <groupId>io.vertx</groupId>
      <artifactId>vertx-hawkular-metrics</artifactId>
      <version>3.4.0</version>
    </dependency>

And Gradle users, to their build file:

    compile 'io.vertx:vertx-hawkular-metrics:3.4.0'

Vert.x does not enable SPI implementations by default. You must enable metric collection in the Vert.x options:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true
      }
    })

## Configuration

### Remote Hawkular server

By default, vertx-hawkular-metrics sends metrics to a Hawkular server listening on `localhost` port `8080`. But in production, the Hawkular server will likely run on a separate machine:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'host' => "hawkular.example.com",
        'port' => 8080
      }
    })

### Tenant selection

Hawkular Metrics is a multi-tenant solution, and vertx-hawkular-metrics can send metrics for a tenant other than `default`:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'tenant' => "sales-department"
      }
    })

### Connecting to a Hawkular server

Requests sent to a Hawkular server must be authenticated and tenant must be set to `hawkular`:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'tenant' => "hawkular",
        'authenticationOptions' => {
          'enabled' => true,
          'id' => "username",
          'secret' => "password"
        }
      }
    })

### Openshift Metrics token authentication

When working with Openshift’s internal Metrics server, you can configure token authentication with a custom HTTP header:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'tenant' => "my-namespace",
        'httpHeaders' => {
          'Authorization' => "Bearer xkjdksf9890-shjkjhkjlkjlk"
        }
      }
    })

### HTTPS and other HTTP related options

vertx-hawkular-metrics communicates with the Hawkular server over HTTP. In order to communicate over HTTPS, set the `ssl` flag to true:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'host' => "hawkular.example.com",
        'port' => 443,
        'httpOptions' => {
          'ssl' => true
        }
      }
    })

Note that all the usual `HttpClientOptions` properties can be used for SSL setup or client tuning.

Please refer to `VertxHawkularOptions` for an exhaustive list of options.

## Vert.x core tools metrics

This section lists all the metrics generated by monitoring the Vert.x core tools.

### Net Client

Metric type | Metric name | Description
--- | --- | ---
Gauge | `vertx.net.client.<host>:<port>.connections` | Number of connections to the remote host currently opened.
Counter | `vertx.net.client.<host>:<port>.bytesReceived` | Total number of bytes received from the remote host.
Counter | `vertx.net.client.<host>:<port>.bytesSent` | Total number of bytes sent to the remote host.
Counter | `vertx.net.client.<host>:<port>.errorCount` | Total number of errors.

### HTTP Client

Metric type | Metric name | Description
--- | --- | ---
Gauge | `vertx.http.client.<host>:<port>.connections` | Number of connections to the remote host currently opened.
Counter | `vertx.http.client.<host>:<port>.bytesReceived` | Total number of bytes received from the remote host.
Counter | `vertx.http.client.<host>:<port>.bytesSent` | Total number of bytes sent to the remote host.
Counter | `vertx.http.client.<host>:<port>.errorCount` | Total number of errors.
Gauge | `vertx.http.client.<host>:<port>.requests` | Number of requests waiting for a response.
Counter | `vertx.http.client.<host>:<port>.requestCount` | Total number of requests sent.
Counter | `vertx.http.client.<host>:<port>.responseTime` | Cumulated response time.
Gauge | `vertx.http.client.<host>:<port>.wsConnections` | Number of websockets currently opened.

### Datagram socket

Metric type | Metric name | Description
--- | --- | ---
Counter | `vertx.datagram.<host>:<port>.bytesReceived` | Total number of bytes received on the `<host>:<port>` listening address.
Counter | `vertx.datagram.<host>:<port>.bytesSent` | Total number of bytes sent to the remote host.
Counter | `vertx.datagram.errorCount` | Total number of errors.

### Net Server

Metric type | Metric name | Description
--- | --- | ---
Gauge | `vertx.net.server.<host>:<port>.connections` | Number of opened connections to the Net Server listening on the `<host>:<port>` address.
Counter | `vertx.net.server.<host>:<port>.bytesReceived` | Total number of bytes received by the Net Server listening on the `<host>:<port>` address.
Counter | `vertx.net.server.<host>:<port>.bytesSent` | Total number of bytes sent to the Net Server listening on the `<host>:<port>` address.
Counter | `vertx.net.server.<host>:<port>.errorCount` | Total number of errors.

### HTTP Server

Metric type | Metric name | Description
--- | --- | ---
Gauge | `vertx.http.server.<host>:<port>.connections` | Number of opened connections to the HTTP Server listening on the `<host>:<port>` address.
Counter | `vertx.http.server.<host>:<port>.bytesReceived` | Total number of bytes received by the HTTP Server listening on the `<host>:<port>` address.
Counter | `vertx.http.server.<host>:<port>.bytesSent` | Total number of bytes sent to the HTTP Server listening on the `<host>:<port>` address.
Counter | `vertx.http.server.<host>:<port>.errorCount` | Total number of errors.
Gauge | `vertx.http.client.<host>:<port>.requests` | Number of requests being processed.
Counter | `vertx.http.client.<host>:<port>.requestCount` | Total number of requests processed.
Counter | `vertx.http.client.<host>:<port>.processingTime` | Cumulated request processing time.
Gauge | `vertx.http.client.<host>:<port>.wsConnections` | Number of websockets currently opened.

### Event Bus

Metric type | Metric name | Description
--- | --- | ---
Gauge | `vertx.eventbus.handlers` | Number of event bus handlers.
Counter | `vertx.eventbus.errorCount` | Total number of errors.
Counter | `vertx.eventbus.bytesWritten` | Total number of bytes sent while sending messages to event bus cluster peers.
Counter | `vertx.eventbus.bytesRead` | Total number of bytes received while reading messages from event bus cluster peers.
Gauge | `vertx.eventbus.pending` | Number of messages not processed yet. One message published will count for `N` pending if `N` handlers are registered to the corresponding address.
Gauge | `vertx.eventbus.pendingLocal` | Like `vertx.eventbus.pending`, for local messages only.
Gauge | `vertx.eventbus.pendingRemote` | Like `vertx.eventbus.pending`, for remote messages only.
Counter | `vertx.eventbus.publishedMessages` | Total number of messages published (publish / subscribe).
Counter | `vertx.eventbus.publishedLocalMessages` | Like `vertx.eventbus.publishedMessages`, for local messages only.
Counter | `vertx.eventbus.publishedRemoteMessages` | Like `vertx.eventbus.publishedMessages`, for remote messages only.
Counter | `vertx.eventbus.sentMessages` | Total number of messages sent (point-to-point).
Counter | `vertx.eventbus.sentLocalMessages` | Like `vertx.eventbus.sentMessages`, for local messages only.
Counter | `vertx.eventbus.sentRemoteMessages` | Like `vertx.eventbus.sentMessages`, for remote messages only.
Counter | `vertx.eventbus.receivedMessages` | Total number of messages received.
Counter | `vertx.eventbus.receivedLocalMessages` | Like `vertx.eventbus.receivedMessages`, for remote messages only.
Counter | `vertx.eventbus.receivedRemoteMessages` | Like `vertx.eventbus.receivedMessages`, for remote messages only.
Counter | `vertx.eventbus.deliveredMessages` | Total number of messages delivered to handlers.
Counter | `vertx.eventbus.deliveredLocalMessages` | Like `vertx.eventbus.deliveredMessages`, for remote messages only.
Counter | `vertx.eventbus.deliveredRemoteMessages` | Like `vertx.eventbus.deliveredMessages`, for remote messages only.
Counter | `vertx.eventbus.replyFailures` | Total number of message reply failures.
Counter | `vertx.eventbus.<address>.processingTime` | Cumulated processing time for handlers listening to the `address`.

## Vert.x pool metrics

This section lists all the metrics generated by monitoring Vert.x pools.

There are two types currently supported:

- worker (see `WorkerExecutor`)

- datasource (created with Vert.x JDBC client)

Note that Vert.x creates two worker pools upfront, vert.x-worker-thread and vert.x-internal-blocking.

All metrics are prefixed with `<type>.<name>.`. For example, `worker.vert.x-internal-blocking.`.

Metric type | Metric name | Description
--- | --- | ---
Counter | `vertx.pool.<type>.<name>.delay` | Cumulated time waiting for a resource (queue time).
Gauge | `vertx.pool.<type>.<name>.queued` | Current number of elements waiting for a resource.
Counter | `vertx.pool.<type>.<name>.queueCount` | Total number of elements queued.
Counter | `vertx.pool.<type>.<name>.usage` | Cumulated time using a resource (i.e. processing time for worker pools).
Gauge | `vertx.pool.<type>.<name>.inUse` | Current number of resources used.
Counter | `vertx.pool.<type>.<name>.completed` | Total number of elements done with the resource (i.e. total number of tasks executed for worker pools).
Gauge | `vertx.pool.<type>.<name>.maxPoolSize` | Maximum pool size, only present if it could be determined.
Gauge | `vertx.pool.<type>.<name>.inUse` | Pool usage ratio, only present if maximum pool size could be determined.

## User defined metrics

Users can send their own metrics to the Hawkular server. In order to do so, the event bus metrics bridge must be enabled:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'metricsBridgeEnabled' => true
      }
    })

By default, the metrics bus handler is listening to the `hawkular.metrics` address. But the bridge address can be configured:

    require 'vertx/vertx'
    vertx = Vertx::Vertx.vertx({
      'metricsOptions' => {
        'enabled' => true,
        'metricsBridgeEnabled' => true,
        'metricsBridgeAddress' => "__hawkular_metrics"
      }
    })

The metrics bridge handler expects messages in the JSON format. The JSON object must at least provide a metric `id` and a numerical `value`:

    message = {
      'id' => "myapp.files.opened",
      'value' => 7
    }
    @vertx.event_bus().publish("metrics", message)

The handler will assume the metric is a gauge and will assign a timestamp corresponding to the time when the message was processed. If the metric is a counter or if you prefer explicit configuration, set the `type` and `timestamp` attributes:

    message = {
      'id' => "myapp.files.opened",
      'type' => "counter",
      'timestamp' => 189898098098908,
      'value' => 7
    }
    @vertx.event_bus().publish("metrics", message)

Note that Hawkular understands all timestamps as milliseconds since January 1, 1970, 00:00:00 UTC.