diff --git a/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java b/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java
index 3a887be72d7..57fcff76715 100644
--- a/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java
+++ b/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/Watcher.java
@@ -34,6 +34,7 @@ import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.index.IndexModule;
 import org.elasticsearch.license.XPackLicenseState;
+import org.elasticsearch.node.Node;
 import org.elasticsearch.plugins.ActionPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.ScriptPlugin;
@@ -464,13 +465,22 @@ public class Watcher extends Plugin implements ActionPlugin, ScriptPlugin {
      * Use five times the number of processors up until 50, then stick with the
      * number of processors.
      *
+     * If the node is not a data node, we will never need so much threads, so we
+     * just return 1 here, which still allows to execute a watch locally, but
+     * there is no need of managing any more threads here
+     *
      * @param settings The current settings
      * @return A number between 5 and the number of processors
      */
     static int getWatcherThreadPoolSize(Settings settings) {
-        int numberOfProcessors = EsExecutors.numberOfProcessors(settings);
-        long size = Math.max(Math.min(5 * numberOfProcessors, 50), numberOfProcessors);
-        return Math.toIntExact(size);
+        boolean isDataNode = Node.NODE_DATA_SETTING.get(settings);
+        if (isDataNode) {
+            int numberOfProcessors = EsExecutors.numberOfProcessors(settings);
+            long size = Math.max(Math.min(5 * numberOfProcessors, 50), numberOfProcessors);
+            return Math.toIntExact(size);
+        } else {
+            return 1;
+        }
     }
 
     @Override
diff --git a/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherPluginTests.java b/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherPluginTests.java
index 2516ca5e4d6..c7c2b59caaa 100644
--- a/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherPluginTests.java
+++ b/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/WatcherPluginTests.java
@@ -89,5 +89,11 @@ public class WatcherPluginTests extends ESTestCase {
         assertThat(Watcher.getWatcherThreadPoolSize(Settings.builder().put("processors", 50).build()), is(50));
         assertThat(Watcher.getWatcherThreadPoolSize(Settings.builder().put("processors", 51).build()), is(51));
         assertThat(Watcher.getWatcherThreadPoolSize(Settings.builder().put("processors", 96).build()), is(96));
+
+        Settings noDataNodeSettings = Settings.builder()
+                .put("processors", scaledRandomIntBetween(1, 100))
+                .put("node.data", false)
+                .build();
+        assertThat(Watcher.getWatcherThreadPoolSize(noDataNodeSettings), is(1));
     }
 }