Block older operations on primary term transition

Today a replica learns of a new primary term via a cluster state update
and there is not a clean transition between the older primary term and
the newer primary term. This commit modifies this situation so that:
 - a replica shard learns of a new primary term via replication
   operations executed under the mandate of the new primary
 - when a replica shard learns of a new primary term, it blocks
   operations on older terms from reaching the engine, with a clear
   transition point between the operations on the older term and the
   operations on the newer term

This work paves the way for a primary/replica sync on primary
promotion. Future work will also ensure a clean transition point on a
promoted primary, and prepare a replica shard for a sync with the
promoted primary.

Relates #24779

2 files changed, 4 insertions, 4 deletions

diff --git a/core/src/test/java/org/elasticsearch/action/support/replication/TransportReplicationActionTests.java b/core/src/test/java/org/elasticsearch/action/support/replication/TransportReplicationActionTests.java
index 0f8071cce3..89026d9d1d 100644
--- a/core/src/test/java/org/elasticsearch/action/support/replication/TransportReplicationActionTests.java
+++ b/core/src/test/java/org/elasticsearch/action/support/replication/TransportReplicationActionTests.java
@@ -1091,7 +1091,7 @@ public class TransportReplicationActionTests extends ESTestCase {
             count.incrementAndGet();
             callback.onResponse(count::decrementAndGet);
             return null;
-        }).when(indexShard).acquirePrimaryOperationLock(any(ActionListener.class), anyString());
+        }).when(indexShard).acquirePrimaryOperationPermit(any(ActionListener.class), anyString());
         doAnswer(invocation -> {
             long term = (Long)invocation.getArguments()[0];
             ActionListener<Releasable> callback = (ActionListener<Releasable>) invocation.getArguments()[1];
@@ -1103,7 +1103,7 @@ public class TransportReplicationActionTests extends ESTestCase {
             count.incrementAndGet();
             callback.onResponse(count::decrementAndGet);
             return null;
-        }).when(indexShard).acquireReplicaOperationLock(anyLong(), any(ActionListener.class), anyString());
+        }).when(indexShard).acquireReplicaOperationPermit(anyLong(), any(ActionListener.class), anyString());
         when(indexShard.routingEntry()).thenAnswer(invocationOnMock -> {
             final ClusterState state = clusterService.state();
             final RoutingNode node = state.getRoutingNodes().node(state.nodes().getLocalNodeId());
diff --git a/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java b/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
index ca16e816b4..f0690ad67b 100644
--- a/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
+++ b/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
@@ -444,7 +444,7 @@ public class TransportWriteActionTests extends ESTestCase {
             count.incrementAndGet();
             callback.onResponse(count::decrementAndGet);
             return null;
-        }).when(indexShard).acquirePrimaryOperationLock(any(ActionListener.class), anyString());
+        }).when(indexShard).acquirePrimaryOperationPermit(any(ActionListener.class), anyString());
         doAnswer(invocation -> {
             long term = (Long)invocation.getArguments()[0];
             ActionListener<Releasable> callback = (ActionListener<Releasable>) invocation.getArguments()[1];
@@ -456,7 +456,7 @@ public class TransportWriteActionTests extends ESTestCase {
             count.incrementAndGet();
             callback.onResponse(count::decrementAndGet);
             return null;
-        }).when(indexShard).acquireReplicaOperationLock(anyLong(), any(ActionListener.class), anyString());
+        }).when(indexShard).acquireReplicaOperationPermit(anyLong(), any(ActionListener.class), anyString());
         when(indexShard.routingEntry()).thenAnswer(invocationOnMock -> {
             final ClusterState state = clusterService.state();
             final RoutingNode node = state.getRoutingNodes().node(state.nodes().getLocalNodeId());