Tests: ThreadDumpOnFailureRule

solr/test-framework/src/java/org/apache/solr/SolrTestCase.java

@@ -41,6 +41,7 @@
 import org.apache.solr.util.LogLevelTestRule;
 import org.apache.solr.util.RevertDefaultThreadHandlerRule;
 import org.apache.solr.util.StartupLoggingUtils;
+import org.apache.solr.util.ThreadDumpOnFailureRule;
 import org.hamcrest.Matcher;
 import org.hamcrest.MatcherAssert;
 import org.junit.AfterClass;
@@ -110,7 +111,8 @@ protected void afterAlways(List<Throwable> errors) {
                     ObjectReleaseTracker.tryClose();
                   }
                 }
-              });
+              })
+          .around(new ThreadDumpOnFailureRule());
 
   /**
    * Sets the <code>solr.configset.default.confdir</code> system property to the value of {@link

solr/test-framework/src/java/org/apache/solr/util/ThreadDumpOnFailureRule.java

@@ -0,0 +1,63 @@
+/*
+ * 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.solr.util;
+
+import org.apache.solr.core.Diagnostics;
+import org.junit.rules.TestWatcher;
+import org.junit.runner.Description;
+
+/**
+ * JUnit rule that captures and logs a thread dump when a test fails with a timeout. This is useful
+ * for debugging flaky tests with timeout issues, as it shows what threads were doing at the time of
+ * failure.
+ *
+ * <p>The thread dump is only captured if the failure throwable or its message contains "Timeout"
+ * (case-insensitive).
+ *
+ * <p>Usage:
+ *
+ * <pre>{@code
+ * @Rule
+ * public TestRule threadDumpRule = new ThreadDumpOnFailureRule();
+ * }</pre>
+ */
+public class ThreadDumpOnFailureRule extends TestWatcher {
+
+  @Override
+  protected void failed(Throwable e, Description description) {
+    if (isTimeoutRelated(e)) {
+      Diagnostics.logThreadDumps(
+          "============ THREAD DUMP ON TIMEOUT FAILURE: "
+              + description.getDisplayName()
+              + " ============\nFailure: "
+              + e.getClass().getSimpleName()
+              + ": "
+              + e.getMessage());
+    }
+  }
+
+  private boolean isTimeoutRelated(Throwable e) {
+    if (e == null) {
+      return false;
+    }
+    if (e.toString().contains("Timeout")) {
+      return true;
+    }
+    // Check the cause recursively
+    return isTimeoutRelated(e.getCause());
+  }
+}