rename average to max for queue latency

Author: DiannaHohensee

server/src/internalClusterTest/java/org/elasticsearch/index/shard/IndexShardIT.java

@@ -347,7 +347,7 @@ public void testNodeWriteLoadsArePresent() {
                 assertNotNull(writeThreadPoolStats);
                 assertThat(writeThreadPoolStats.totalThreadPoolThreads(), greaterThanOrEqualTo(0));
                 assertThat(writeThreadPoolStats.averageThreadPoolUtilization(), greaterThanOrEqualTo(0.0f));
-                assertThat(writeThreadPoolStats.averageThreadPoolQueueLatencyMillis(), greaterThanOrEqualTo(0L));
+                assertThat(writeThreadPoolStats.maxThreadPoolQueueLatencyMillis(), greaterThanOrEqualTo(0L));
             }
         } finally {
             updateClusterSettings(

server/src/main/java/org/elasticsearch/cluster/NodeUsageStatsForThreadPools.java

@@ -70,13 +70,12 @@ public String toString() {
      *
      * @param totalThreadPoolThreads Total number of threads in the thread pool.
      * @param averageThreadPoolUtilization Percent of thread pool threads that are in use, averaged over some period of time.
-     * @param averageThreadPoolQueueLatencyMillis How much time tasks spend in the thread pool queue. Zero if there is nothing being queued
-     *                                            in the write thread pool.
+     * @param maxThreadPoolQueueLatencyMillis The max time any task has spent in the thread pool queue. Zero if no task is queued.
      */
     public record ThreadPoolUsageStats(
         int totalThreadPoolThreads,
         float averageThreadPoolUtilization,
-        long averageThreadPoolQueueLatencyMillis
+        long maxThreadPoolQueueLatencyMillis
     ) implements Writeable {
 
         public ThreadPoolUsageStats(StreamInput in) throws IOException {
@@ -87,12 +86,12 @@ public ThreadPoolUsageStats(StreamInput in) throws IOException {
         public void writeTo(StreamOutput out) throws IOException {
             out.writeVInt(this.totalThreadPoolThreads);
             out.writeFloat(this.averageThreadPoolUtilization);
-            out.writeVLong(this.averageThreadPoolQueueLatencyMillis);
+            out.writeVLong(this.maxThreadPoolQueueLatencyMillis);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(totalThreadPoolThreads, averageThreadPoolUtilization, averageThreadPoolQueueLatencyMillis);
+            return Objects.hash(totalThreadPoolThreads, averageThreadPoolUtilization, maxThreadPoolQueueLatencyMillis);
         }
 
         @Override
@@ -101,8 +100,8 @@ public String toString() {
                 + totalThreadPoolThreads
                 + ", averageThreadPoolUtilization="
                 + averageThreadPoolUtilization
-                + ", averageThreadPoolQueueLatencyMillis="
-                + averageThreadPoolQueueLatencyMillis
+                + ", maxThreadPoolQueueLatencyMillis="
+                + maxThreadPoolQueueLatencyMillis
                 + "]";
         }
 
@@ -113,7 +112,7 @@ public boolean equals(Object o) {
             ThreadPoolUsageStats other = (ThreadPoolUsageStats) o;
             return totalThreadPoolThreads == other.totalThreadPoolThreads
                 && averageThreadPoolUtilization == other.averageThreadPoolUtilization
-                && averageThreadPoolQueueLatencyMillis == other.averageThreadPoolQueueLatencyMillis;
+                && maxThreadPoolQueueLatencyMillis == other.maxThreadPoolQueueLatencyMillis;
         }
 
     } // ThreadPoolUsageStats

server/src/test/java/org/elasticsearch/cluster/ClusterInfoTests.java

@@ -72,7 +72,7 @@ private static Map<String, NodeUsageStatsForThreadPools> randomNodeUsageStatsFor
             NodeUsageStatsForThreadPools.ThreadPoolUsageStats writeThreadPoolUsageStats =
                 new NodeUsageStatsForThreadPools.ThreadPoolUsageStats(/* totalThreadPoolThreads= */ randomIntBetween(1, 16),
                     /* averageThreadPoolUtilization= */ randomFloat(),
-                    /* averageThreadPoolQueueLatencyMillis= */ randomLongBetween(0, 50000)
+                    /* maxThreadPoolQueueLatencyMillis= */ randomLongBetween(0, 50000)
                 );
             Map<String, NodeUsageStatsForThreadPools.ThreadPoolUsageStats> usageStatsForThreadPools = new HashMap<>();
             usageStatsForThreadPools.put(ThreadPool.Names.WRITE, writeThreadPoolUsageStats);