Github user mccheah commented on a diff in the pull request:

    https://github.com/apache/spark/pull/21221#discussion_r207004997
  
    --- Diff: 
core/src/main/scala/org/apache/spark/executor/ExecutorMetrics.scala ---
    @@ -0,0 +1,81 @@
    +/*
    + * Licensed to the Apache Software Foundation (ASF) under one or more
    + * contributor license agreements.  See the NOTICE file distributed with
    + * this work for additional information regarding copyright ownership.
    + * The ASF 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.
    + */
    +package org.apache.spark.executor
    +
    +import org.apache.spark.annotation.DeveloperApi
    +import org.apache.spark.metrics.ExecutorMetricType
    +
    +/**
    + * :: DeveloperApi ::
    + * Metrics tracked for executors and the driver.
    + *
    + * Executor-level metrics are sent from each executor to the driver as 
part of the Heartbeat.
    + */
    +@DeveloperApi
    +class ExecutorMetrics private[spark] extends Serializable {
    +
    +  // Metrics are indexed by MetricGetter.values
    +  private val metrics = new Array[Long](ExecutorMetricType.values.length)
    --- End diff --
    
    Yup that's fine - I did some googling, unfortunately there isn't a great 
way to iterate over fields of a case class. You could create a thin wrapper 
object around the array instead though, if we really think the nicer API is 
worthwhile:
    
    ```
    case class Metrics(values: Seq[Long]) {
      def someMetric1(): Long = values(0)
      def ....
      def ...
    }
    ```
    
    Or even this:
    
    ```
    case class Metrics(metric1: Long, metric2: Long, metfic3: Long, ...) {
      def values(): Seq[Long] = Seq(metric1, metric2, metric3, ...)
    }
    ```
    
    The latter which would be better because you'd be guaranteed to create the 
struct with the right number of metrics. Though such abstractions are not 
necessary by any means.


---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org

Reply via email to