Fix flaky slowlog test

Signed-off-by: David Zane <davizane@amazon.com>

Author: dzane17

CHANGELOG.md

@@ -36,6 +36,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Harden detection of HTTP/3 support by ensuring Quic native libraries are available for the target platform ([#20680](https://github.com/opensearch-project/OpenSearch/pull/20680))
 - Fallback to netty client if AWS Crt client is not available on the target platform / architecture ([#20698](https://github.com/opensearch-project/OpenSearch/pull/20698))
 - Fix ShardSearchFailure in transport-grpc ([#20641](https://github.com/opensearch-project/OpenSearch/pull/20641))
+- Fix flaky slowlog test ([#20726](https://github.com/opensearch-project/OpenSearch/pull/20726))
 
 ### Dependencies
 - Bump shadow-gradle-plugin from 8.3.9 to 9.3.1 ([#20569](https://github.com/opensearch-project/OpenSearch/pull/20569))

server/src/test/java/org/opensearch/action/search/SearchRequestSlowLogTests.java

@@ -88,27 +88,25 @@ public static void cleanup() {
 
     public void testMultipleSlowLoggersUseSingleLog4jLogger() {
         LoggerContext context = (LoggerContext) LogManager.getContext(false);
+        String loggerName = SearchRequestSlowLog.CLUSTER_SEARCH_REQUEST_SLOWLOG_PREFIX + ".SearchRequestSlowLog";
 
-        new MockSearchPhaseContext(1);
         ClusterService clusterService1 = ClusterServiceUtils.createClusterService(
             Settings.EMPTY,
             new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
             null
         );
         new SearchRequestSlowLog(clusterService1);
-        int numberOfLoggersBefore = context.getLoggers().size();
+        Logger logger1 = context.getLogger(loggerName);
 
-        new MockSearchPhaseContext(1);
         ClusterService clusterService2 = ClusterServiceUtils.createClusterService(
             Settings.EMPTY,
             new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
             null
         );
-        new SearchRequestOperationsCompositeListenerFactory();
         new SearchRequestSlowLog(clusterService2);
+        Logger logger2 = context.getLogger(loggerName);
 
-        int numberOfLoggersAfter = context.getLoggers().size();
-        assertThat(numberOfLoggersAfter, equalTo(numberOfLoggersBefore));
+        assertSame(logger1, logger2);
     }
 
     public void testOnRequestEnd() {