Zookeeper 4981 Test

zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/ZooKeeper4981Test.java

@@ -0,0 +1,170 @@
+package org.apache.zookeeper.server.quorum;
+
+
+
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.ZooDefs;
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.data.Stat;
+import org.apache.zookeeper.test.QuorumUtil;
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Method;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Compatible version of EphemeralCrashTest for 3.6.x+ ZooKeeper branches.
+ * Automatically adapts to QuorumUtil method names (killServer/shutdown/createClient/getLeader etc.)
+ */
+public class ZooKeeper4981Test {
+
+    @Test
+    public void reproduceEphemeralAfterFollowerCrash() throws Exception {
+        System.out.println("🧪 Starting EphemeralCrashTest...");
+
+        QuorumUtil qu = new QuorumUtil(5);
+        boolean started = false;
+        for (int attempt = 1; attempt <= 3; attempt++) {
+            try {
+                System.out.println("🟢 Attempting to start quorum, try " + attempt);
+                invokeIfExists(qu, "startAll");
+                started = true;
+                break;
+            } catch (Exception e) {
+                System.out.println("⚠️  Quorum start failed: " + e.getMessage());
+                Thread.sleep(3000);
+            }
+        }
+        assertTrue(started, "Quorum should start successfully");
+
+        invokeIfExists(qu, "startAll");
+        TimeUnit.SECONDS.sleep(2);
+
+        // Find leader (try both getLeaderIndex and getLeader)
+        int leader = -1;
+        try {
+            leader = (int) invokeIfExists(qu, "getLeaderIndex");
+        } catch (Exception ignored) {
+            try {
+                leader = (int) invokeIfExists(qu, "getLeader");
+            } catch (Exception ignored2) {}
+        }
+
+        System.out.println("✅ Leader found: " + leader);
+        assertTrue(leader >= 0, "Leader should be present");
+
+        // Pick a follower (not leader)
+        int client1Server = (leader == 4 ? 3 : 4);
+
+        // Connect client1
+        ZooKeeper cli1 = connectClientCompat(qu, client1Server);
+        assertNotNull(cli1, "Client1 connected");
+
+        // Step 1: Create znodes
+        createOrReplace(cli1, "/bug", "hello");
+        createOrReplace(cli1, "/delete", "hello");
+
+        // Step 2: Crash follower zk5
+        crashCompat(qu, 4);
+
+        // Step 3: Reconnect client1
+        cli1.close();
+        cli1 = connectClientCompat(qu, client1Server);
+        assertNotNull(cli1, "Client1 reconnected");
+
+        // Update /bug to "nice"
+        Stat st = cli1.exists("/bug", false);
+        cli1.setData("/bug", "nice".getBytes(), st.getVersion());
+        byte[] data = cli1.getData("/bug", false, null);
+        assertEquals("nice", new String(data), "/bug should be updated to 'nice'");
+
+        // Delete /delete
+        if (cli1.exists("/delete", false) != null)
+            cli1.delete("/delete", -1);
+
+        // Create ephemeral /eph
+        cli1.create("/eph", "ephem".getBytes(),
+                ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
+        assertNotNull(cli1.exists("/eph", false), "Ephemeral /eph created");
+
+        // Step 4: Crash the client1’s server (zk4)
+        crashCompat(qu, client1Server);
+
+        // Step 5: Connect client2 to another node
+        int client2Server = (client1Server == 0) ? 1 : 0;
+        ZooKeeper cli2 = connectClientCompat(qu, client2Server);
+
+        // Wait for ephemeral cleanup
+        TimeUnit.SECONDS.sleep(2);
+
+        // Check if /eph still exists
+        Stat eph = cli2.exists("/eph", false);
+        if (eph != null) {
+            System.out.println("🐞 BUG REPRODUCED: /eph still visible after client1 crash");
+        } else {
+            System.out.println("✅ /eph cleaned correctly after crash");
+        }
+
+        assertNull(eph, "/eph should not exist after client1 disconnects");
+
+        cli1.close();
+        cli2.close();
+        invokeIfExists(qu, "shutdownAll");
+    }
+
+    // --- Helpers ---
+
+    private static Object invokeIfExists(Object obj, String methodName, Object... args) {
+        for (Method m : obj.getClass().getMethods()) {
+            if (m.getName().equals(methodName)) {
+                try {
+                    return m.invoke(obj, args);
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
+        return null;
+    }
+
+    private static ZooKeeper connectClientCompat(QuorumUtil qu, int idx) throws Exception {
+        // Try all known method names
+        for (String m : new String[]{"connectClient", "createClient", "connectToServer"}) {
+            for (Method method : qu.getClass().getMethods()) {
+                if (method.getName().equals(m)) {
+                    Object res = method.invoke(qu, idx);
+                    if (res instanceof ZooKeeper) return (ZooKeeper) res;
+                    if (res != null && res.getClass().getSimpleName().contains("ZooKeeper"))
+                        return (ZooKeeper) res;
+                }
+            }
+        }
+        throw new IllegalStateException("No suitable connectClient method found in QuorumUtil");
+    }
+
+    private static void crashCompat(QuorumUtil qu, int idx) {
+        for (String m : new String[]{"shutdown", "shutdownServer", "kill", "killServer"}) {
+            for (Method method : qu.getClass().getMethods()) {
+                if (method.getName().equals(m)) {
+                    try {
+                        method.invoke(qu, idx);
+                        System.out.println("💥 Crashed server " + idx);
+                        return;
+                    } catch (Exception e) {
+                        // try next
+                    }
+                }
+            }
+        }
+        throw new IllegalStateException("No method to crash server found in QuorumUtil");
+    }
+
+    private static void createOrReplace(ZooKeeper zk, String path, String val) throws Exception {
+        if (zk.exists(path, false) != null) {
+            zk.delete(path, -1);
+        }
+        zk.create(path, val.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
+    }
+}