Class DefaultMetrics

lib/metrics/default-metrics.js:39–198

* A default implementation of [ClientMetrics]module:metrics~ClientMetrics that exposes the driver events as * Node.js events. * * An instance of [DefaultMetrics]module:metrics~DefaultMetrics is configured by default in the client, * you can access this instance using [Cli

 * defaultMetrics.responses.on('increment', latency => myHistogram.record(latency));
 */
class DefaultMetrics extends ClientMetrics {
  /**
   * Creates a new instance of [DefaultMetrics]{@link module:metrics~DefaultMetrics}.
   */
  constructor() {
    super();

    /**
     * Emits all the error events.
     * <p>Use each of the properties to measure events of specific errors.</p>
     * @type {EventEmitter}
     * @property {EventEmitter} authentication Emits the authentication timeout error events.
     * @property {EventEmitter} clientTimeout Emits the client timeout error events.
     * @property {EventEmitter} connection Emits the connection error events.
     * @property {EventEmitter} readTimeout Emits the read timeout error events obtained from the server.
     * @property {EventEmitter} other Emits the error events, that are not part of the other categories.
     * @property {EventEmitter} unavailable Emits the unavailable error events obtained from the server.
     * @property {EventEmitter} writeTimeout Emits the write timeout error events obtained from the server
     */
    this.errors = new EventEmitter();
    this.errors.authentication = new EventEmitter();
    this.errors.clientTimeout = new EventEmitter();
    this.errors.connection = new EventEmitter();
    this.errors.other = new EventEmitter();
    this.errors.readTimeout = new EventEmitter();
    this.errors.unavailable = new EventEmitter();
    this.errors.writeTimeout = new EventEmitter();

    /**
     * Emits all the retry events.
     * <p>Use each of the properties to measure events of specific retries.</p>
     * @type {EventEmitter}
     * @property {EventEmitter} clientTimeout Emits when an execution is retried as a result of an client timeout.
     * @property {EventEmitter} other Emits the error events, that are not part of the other categories.
     * @property {EventEmitter} readTimeout Emits an execution is retried as a result of an read timeout error from the
     * server (coordinator to replica).
     * @property {EventEmitter} unavailable Emits an execution is retried as a result of an unavailable error from the
     * server.
     * @property {EventEmitter} writeTimeout Emits an execution is retried as a result of a write timeout error from the
     * server (coordinator to replica).
     */
    this.retries = new EventEmitter();
    this.retries.clientTimeout = new EventEmitter();
    this.retries.other = new EventEmitter();
    this.retries.readTimeout = new EventEmitter();
    this.retries.unavailable = new EventEmitter();
    this.retries.writeTimeout = new EventEmitter();

    /**
     * Emits events when a speculative execution is started.
     * @type {EventEmitter}
     */
    this.speculativeExecutions = new EventEmitter();

    /**
     * Emits events when an error is ignored by the retry policy.
     * @type {EventEmitter}
     */