No refresh on shard activation needed (#28013)

A shard is fully baked when it moves to POST_RECOVERY. There is no need to do an extra refresh on shard activation again as the shard has already been refreshed when it moved to POST_RECOVERY.

Author: ywelsch

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -403,13 +403,7 @@ public void updateShardState(final ShardRouting newRouting,
 
             if (state == IndexShardState.POST_RECOVERY && newRouting.active()) {
                 assert currentRouting.active() == false : "we are in POST_RECOVERY, but our shard routing is active " + currentRouting;
-                // we want to refresh *before* we move to internal STARTED state
-                try {
-                    getEngine().refresh("cluster_state_started");
-                } catch (Exception e) {
-                    logger.debug("failed to refresh due to move to cluster wide started", e);
-                }
-                
+
                 if (newRouting.primary()) {
                     final DiscoveryNode recoverySourceNode = recoveryState.getSourceNode();
                     final Engine engine = getEngine();

server/src/test/java/org/elasticsearch/index/shard/IndexShardTests.java

@@ -1168,14 +1168,14 @@ public void testShardStats() throws IOException {
 
     public void testRefreshMetric() throws IOException {
         IndexShard shard = newStartedShard();
-        assertThat(shard.refreshStats().getTotal(), equalTo(3L)); // refresh on: finalize, end of recovery and on starting shard
+        assertThat(shard.refreshStats().getTotal(), equalTo(2L)); // refresh on: finalize and end of recovery
         long initialTotalTime = shard.refreshStats().getTotalTimeInMillis();
         // check time advances
         for (int i = 1; shard.refreshStats().getTotalTimeInMillis() == initialTotalTime; i++) {
             indexDoc(shard, "test", "test");
-            assertThat(shard.refreshStats().getTotal(), equalTo(3L + i - 1));
+            assertThat(shard.refreshStats().getTotal(), equalTo(2L + i - 1));
             shard.refresh("test");
-            assertThat(shard.refreshStats().getTotal(), equalTo(3L + i));
+            assertThat(shard.refreshStats().getTotal(), equalTo(2L + i));
             assertThat(shard.refreshStats().getTotalTimeInMillis(), greaterThanOrEqualTo(initialTotalTime));
         }
         long refreshCount = shard.refreshStats().getTotal();