Disallow multiple concurrent recovery attempts for same target shard (#25428)

The primary shard uses the GlobalCheckPointTracker to track local checkpoint information of recovering and started replicas in order to calculate the global checkpoint. As the tracker is updated through recoveries as well, it is easier to reason about the tracker if we can ensure that there are no concurrent recovery attempts for the same target shard (which can happen in case of network disconnects).

1 files changed, 55 insertions, 0 deletions

diff --git a/core/src/test/java/org/elasticsearch/indices/recovery/PeerRecoverySourceServiceTests.java b/core/src/test/java/org/elasticsearch/indices/recovery/PeerRecoverySourceServiceTests.java
new file mode 100644
index 0000000000..0e1f37c287
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+++ b/core/src/test/java/org/elasticsearch/indices/recovery/PeerRecoverySourceServiceTests.java
@@ -0,0 +1,55 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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.elasticsearch.indices.recovery;
+
+import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.settings.ClusterSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.shard.IndexShard;
+import org.elasticsearch.index.shard.IndexShardTestCase;
+import org.elasticsearch.indices.IndicesService;
+import org.elasticsearch.transport.TransportService;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.mockito.Mockito.mock;
+
+public class PeerRecoverySourceServiceTests extends IndexShardTestCase {
+
+    public void testDuplicateRecoveries() throws IOException {
+        IndexShard primary = newStartedShard(true);
+        PeerRecoverySourceService peerRecoverySourceService = new PeerRecoverySourceService(Settings.EMPTY,
+            mock(TransportService.class), mock(IndicesService.class),
+            new RecoverySettings(Settings.EMPTY, new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS)),
+            mock(ClusterService.class));
+        StartRecoveryRequest startRecoveryRequest = new StartRecoveryRequest(primary.shardId(), randomAlphaOfLength(10),
+            getFakeDiscoNode("source"), getFakeDiscoNode("target"), null, randomBoolean(), randomLong(), randomLong());
+        RecoverySourceHandler handler = peerRecoverySourceService.ongoingRecoveries.addNewRecovery(startRecoveryRequest, primary);
+        DelayRecoveryException delayRecoveryException = expectThrows(DelayRecoveryException.class,
+            () -> peerRecoverySourceService.ongoingRecoveries.addNewRecovery(startRecoveryRequest, primary));
+        assertThat(delayRecoveryException.getMessage(), containsString("recovery with same target already registered"));
+        peerRecoverySourceService.ongoingRecoveries.remove(primary, handler);
+        // re-adding after removing previous attempt works
+        handler = peerRecoverySourceService.ongoingRecoveries.addNewRecovery(startRecoveryRequest, primary);
+        peerRecoverySourceService.ongoingRecoveries.remove(primary, handler);
+        closeShards(primary);
+    }
+}