Change downsample threadpool size. (#97714) (#97764)

Changed the downsample threadpool size to one eight of the allocated processors. Downsampling is a cpu intensive operation (search + heavy aggregation that rolls up documents) and could overwhelm a node. On top of this the downsample operation also delegates to force merge api, which has a threadpool that is also bounded to one eight of the allocated processors. Relates to #97141
elastic · Jul 18, 2023 · ff03c34 · ff03c34
1 parent 9728d3d
commit ff03c34
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -559,7 +559,7 @@ static int twiceAllocatedProcessors(final int allocatedProcessors) {
         return boundedBy(2 * allocatedProcessors, 2, Integer.MAX_VALUE);
     }
 
-    static int oneEighthAllocatedProcessors(final int allocatedProcessors) {
+    public static int oneEighthAllocatedProcessors(final int allocatedProcessors) {
         return boundedBy(allocatedProcessors / 8, 1, Integer.MAX_VALUE);
     }
 

diff --git a/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/Rollup.java b/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/Rollup.java
@@ -177,7 +177,7 @@ public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settingsToUse) {
         final FixedExecutorBuilder downsample = new FixedExecutorBuilder(
             settingsToUse,
             Rollup.DOWSAMPLE_TASK_THREAD_POOL_NAME,
-            ThreadPool.searchOrGetThreadPoolSize(EsExecutors.allocatedProcessors(settingsToUse)),
+            ThreadPool.oneEighthAllocatedProcessors(EsExecutors.allocatedProcessors(settingsToUse)),
             Rollup.DOWNSAMPLE_TASK_THREAD_POOL_QUEUE_SIZE,
             "xpack.downsample.thread_pool",
             false