From df2e83ddba1c94e63b15a8ca18c5c8913664ec83 Mon Sep 17 00:00:00 2001
From: Umeshkumar9414 <9414umeshkumar@gmail.com>
Date: Tue, 5 May 2026 13:34:19 +0530
Subject: [PATCH 1/2] HBASE-30142 Resolve NPE while running recoverUnknown
command because null RegionLocation
---
.../org/apache/hadoop/hbase/master/ServerManager.java | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
index 09184975a33c..8f7cf4488349 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
@@ -980,11 +980,14 @@ public synchronized boolean isServerDead(ServerName serverName) {
/**
* Check if a server is unknown. A server can be online, or known to be dead, or unknown to this
* manager (i.e, not online, not known to be dead either; it is simply not tracked by the master
- * any more, for example, a very old previous instance).
+ * any more, for example, a very old previous instance). A null serverName should not be
+ * considered unknown. We set regionLocation null before finding the assign candidate (in-between
+ * region transition) or while marking it OFFLINE/FAILED_OPEN For more info regarding null-check
+ * in this refer HBASE-30142
*/
public boolean isServerUnknown(ServerName serverName) {
- return serverName == null
- || (!onlineServers.containsKey(serverName) && !deadservers.isDeadServer(serverName));
+ return serverName != null
+ && (!onlineServers.containsKey(serverName) && !deadservers.isDeadServer(serverName));
}
public void shutdownCluster() {
From 314f55e8f45a3478e19bca5338f35cf4f6e67bd2 Mon Sep 17 00:00:00 2001
From: Umeshkumar9414 <9414umeshkumar@gmail.com>
Date: Tue, 12 May 2026 03:38:25 +0530
Subject: [PATCH 2/2] HBASE-30142 added JUnit
Generated-by:us.anthropic.claude-opus-4-7
---
...tRecoverUnknownWithNullRegionLocation.java | 112 ++++++++++++++++++
1 file changed, 112 insertions(+)
create mode 100644 hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRecoverUnknownWithNullRegionLocation.java
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRecoverUnknownWithNullRegionLocation.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRecoverUnknownWithNullRegionLocation.java
new file mode 100644
index 000000000000..abf7def5c838
--- /dev/null
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRecoverUnknownWithNullRegionLocation.java
@@ -0,0 +1,112 @@
+/*
+ * 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.hadoop.hbase.master;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.List;
+import org.apache.hadoop.hbase.HBaseTestingUtil;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.RegionInfo;
+import org.apache.hadoop.hbase.client.Table;
+import org.apache.hadoop.hbase.master.assignment.AssignmentManager;
+import org.apache.hadoop.hbase.master.assignment.RegionStateNode;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos;
+
+/**
+ * Test for HBASE-30142. Verifies that {@code scheduleSCPsForUnknownServers} (i.e. the
+ * recoverUnknown HBCK command) does not throw a NullPointerException when a region's
+ * {@code regionLocation} is null while its state is something other than OFFLINE.
+ *
+ * Before HBASE-30142, {@link ServerManager#isServerUnknown(org.apache.hadoop.hbase.ServerName)}
+ * returned {@code true} for a {@code null} server name, so a region whose location had been
+ * temporarily nulled (e.g. between region transitions or while marking it FAILED_OPEN /
+ * ABNORMALLY_CLOSED) was treated as living on an "unknown" server. The downstream call to
+ * {@code shouldSubmitSCP(null)} then dereferenced the null and crashed.
+ */
+@Tag(MasterTests.TAG)
+@Tag(MediumTests.TAG)
+public class TestRecoverUnknownWithNullRegionLocation {
+
+ private static HBaseTestingUtil UTIL;
+ private static final TableName TABLE_NAME =
+ TableName.valueOf("TestRecoverUnknownWithNullRegionLocation");
+ private static final byte[] FAMILY = Bytes.toBytes("cf");
+
+ @BeforeAll
+ public static void setUpBeforeClass() throws Exception {
+ UTIL = new HBaseTestingUtil();
+ UTIL.startMiniCluster(2);
+ }
+
+ @AfterAll
+ public static void tearDownAfterClass() throws Exception {
+ if (UTIL != null) {
+ UTIL.shutdownMiniCluster();
+ }
+ }
+
+ /**
+ * Drive the region into ABNORMALLY_CLOSED through the
+ * {@link AssignmentManager#regionClosedAbnormally(RegionStateNode)} path (the same path SCP
+ * uses). That method also nulls {@code regionLocation} while leaving state non-OFFLINE. Then call
+ * {@code scheduleSCPsForUnknownServers} and assert no NPE.
+ */
+ @Test
+ public void testRecoverUnknownWithAbnormallyClosedRegion() throws Exception {
+ try (Table ignored = UTIL.createTable(TABLE_NAME, FAMILY)) {
+ UTIL.waitTableAvailable(TABLE_NAME);
+
+ HMaster master = UTIL.getMiniHBaseCluster().getMaster();
+ AssignmentManager am = master.getAssignmentManager();
+ List regions = am.getTableRegions(TABLE_NAME, true);
+ assertFalse(regions.isEmpty(), "expected at least one region");
+ RegionStateNode node = am.getRegionStates().getRegionStateNode(regions.get(0));
+ assertNotNull(node, "expected a region state node for the test region");
+
+ node.lock();
+ try {
+ am.regionClosedAbnormally(node).get();
+ } finally {
+ node.unlock();
+ }
+
+ assertTrue(node.isInState(RegionState.State.ABNORMALLY_CLOSED),
+ "regionClosedAbnormally must move state to ABNORMALLY_CLOSED");
+ assertNull(node.getRegionLocation(), "regionClosedAbnormally must null out the location");
+
+ MasterProtos.ScheduleSCPsForUnknownServersResponse response =
+ master.getMasterRpcServices().scheduleSCPsForUnknownServers(null,
+ MasterProtos.ScheduleSCPsForUnknownServersRequest.newBuilder().build());
+ assertEquals(0, response.getPidCount(),
+ "no SCPs should be scheduled for an ABNORMALLY_CLOSED region with null location");
+ }
+ }
+}