Introduce retention lease actions

server/src/main/java/org/elasticsearch/action/ActionModule.java

@@ -19,8 +19,8 @@
 
 package org.elasticsearch.action;
 
-import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.elasticsearch.action.admin.cluster.allocation.ClusterAllocationExplainAction;
 import org.elasticsearch.action.admin.cluster.allocation.TransportClusterAllocationExplainAction;
 import org.elasticsearch.action.admin.cluster.configuration.AddVotingConfigExclusionsAction;
@@ -209,6 +209,7 @@
 import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.settings.SettingsFilter;
+import org.elasticsearch.index.seqno.RetentionLeaseActions;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.persistent.CompletionPersistentTaskAction;
 import org.elasticsearch.persistent.RemovePersistentTaskAction;
@@ -220,6 +221,7 @@
 import org.elasticsearch.rest.RestHandler;
 import org.elasticsearch.rest.action.RestFieldCapabilitiesAction;
 import org.elasticsearch.rest.action.RestMainAction;
+import org.elasticsearch.rest.action.admin.cluster.RestAddVotingConfigExclusionAction;
 import org.elasticsearch.rest.action.admin.cluster.RestCancelTasksAction;
 import org.elasticsearch.rest.action.admin.cluster.RestClearVotingConfigExclusionsAction;
 import org.elasticsearch.rest.action.admin.cluster.RestClusterAllocationExplainAction;
@@ -251,7 +253,6 @@
 import org.elasticsearch.rest.action.admin.cluster.RestRestoreSnapshotAction;
 import org.elasticsearch.rest.action.admin.cluster.RestSnapshotsStatusAction;
 import org.elasticsearch.rest.action.admin.cluster.RestVerifyRepositoryAction;
-import org.elasticsearch.rest.action.admin.cluster.RestAddVotingConfigExclusionAction;
 import org.elasticsearch.rest.action.admin.indices.RestAnalyzeAction;
 import org.elasticsearch.rest.action.admin.indices.RestClearIndicesCacheAction;
 import org.elasticsearch.rest.action.admin.indices.RestCloseIndexAction;
@@ -529,6 +530,11 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(CompletionPersistentTaskAction.INSTANCE, CompletionPersistentTaskAction.TransportAction.class);
         actions.register(RemovePersistentTaskAction.INSTANCE, RemovePersistentTaskAction.TransportAction.class);
 
+        // retention leases
+        actions.register(RetentionLeaseActions.Add.INSTANCE, RetentionLeaseActions.Add.TransportAction.class);
+        actions.register(RetentionLeaseActions.Renew.INSTANCE, RetentionLeaseActions.Renew.TransportAction.class);
+        actions.register(RetentionLeaseActions.Remove.INSTANCE, RetentionLeaseActions.Remove.TransportAction.class);
+
         return unmodifiableMap(actions.getRegistry());
     }
 

server/src/main/java/org/elasticsearch/index/engine/Engine.java

@@ -744,7 +744,7 @@ public enum SearcherScope {
     /**
      * Acquires a lock on the translog files and Lucene soft-deleted documents to prevent them from being trimmed
      */
-    public abstract Closeable acquireRetentionLockForPeerRecovery();
+    public abstract Closeable acquireRetentionLock();
 
     /**
      * Creates a new history snapshot from Lucene for reading operations whose seqno in the requesting seqno range (both inclusive).
@@ -771,6 +771,13 @@ public abstract int estimateNumberOfHistoryOperations(String source,
      */
     public abstract boolean hasCompleteOperationHistory(String source, MapperService mapperService, long startingSeqNo) throws IOException;
 
+    /**
+     * Gets the minimum retained sequence number for this engine.
+     *
+     * @return the minimum retained sequence number
+     */
+    public abstract long getMinRetainedSeqNo();
+
     public abstract TranslogStats getTranslogStats();
 
     /**

server/src/main/java/org/elasticsearch/index/engine/InternalEngine.java

@@ -2567,13 +2567,13 @@ public boolean hasCompleteOperationHistory(String source, MapperService mapperSe
      * Returns the minimum seqno that is retained in the Lucene index.
      * Operations whose seq# are at least this value should exist in the Lucene index.
      */
-    final long getMinRetainedSeqNo() {
+    public final long getMinRetainedSeqNo() {
         assert softDeleteEnabled : Thread.currentThread().getName();
         return softDeletesPolicy.getMinRetainedSeqNo();
     }
 
     @Override
-    public Closeable acquireRetentionLockForPeerRecovery() {
+    public Closeable acquireRetentionLock() {
         if (softDeleteEnabled) {
             return softDeletesPolicy.acquireRetentionLock();
         } else {

server/src/main/java/org/elasticsearch/index/engine/ReadOnlyEngine.java

@@ -272,7 +272,7 @@ public void syncTranslog() {
     }
 
     @Override
-    public Closeable acquireRetentionLockForPeerRecovery() {
+    public Closeable acquireRetentionLock() {
         return () -> {};
     }
 
@@ -311,6 +311,11 @@ public boolean hasCompleteOperationHistory(String source, MapperService mapperSe
         return false;
     }
 
+    @Override
+    public long getMinRetainedSeqNo() {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public TranslogStats getTranslogStats() {
         return translogStats;