// Skip allocation for closed index shards - for new shards and already-batched shards whose index subsequently closed
if (shardRouting.isClosedIndexShard()) {
    return;
}

public boolean isClosedIndexShard() {
    if (unassigned() && unassignedInfo != null) {
        return unassignedInfo.getReason() == UnassignedInfo.Reason.INDEX_CLOSED;
    }
    return false;
}

public void testAlreadyBatchedShardIndexClosedLater() {
    final ShardId shardId = new ShardId("test-index", "_na_", 0);
    final DiscoveryNode node = newNode("node1");

    ShardRouting primaryShard = TestShardRouting.newShardRouting(shardId, node.getId(), true, ShardRoutingState.STARTED);

    ShardRouting replicaShard = ShardRouting.newUnassigned(
        shardId,
        false,
        RecoverySource.PeerRecoverySource.INSTANCE,
        new UnassignedInfo(
            UnassignedInfo.Reason.REPLICA_ADDED,
            "replica added",
            null,
            0,
            System.nanoTime(),
            System.currentTimeMillis(),
            false,
            UnassignedInfo.AllocationStatus.NO_ATTEMPT,
            Collections.emptySet()
        )
    );

    Metadata metadata = Metadata.builder()
        .put(
            IndexMetadata.builder(shardId.getIndexName())
                .settings(settings(Version.CURRENT))
                .numberOfShards(1)
                .numberOfReplicas(1)
                .state(IndexMetadata.State.OPEN)
                .putInSyncAllocationIds(0, Sets.newHashSet(primaryShard.allocationId().getId()))
        )
        .build();

    IndexRoutingTable.Builder indexRoutingTable = IndexRoutingTable.builder(shardId.getIndex())
        .addIndexShard(new IndexShardRoutingTable.Builder(shardId).addShard(primaryShard).addShard(replicaShard).build());

    RoutingTable routingTable = RoutingTable.builder().add(indexRoutingTable).build();

    clusterState = ClusterState.builder(ClusterName.CLUSTER_NAME_SETTING.getDefault(Settings.EMPTY))
        .metadata(metadata)
        .routingTable(routingTable)
        .build();

    testAllocation = new RoutingAllocation(
        new AllocationDeciders(Collections.emptyList()),
        new RoutingNodes(clusterState, false),
        clusterState,
        ClusterInfo.EMPTY,
        SnapshotShardSizeInfo.EMPTY,
        System.nanoTime()
    );

    Set<String> replicaBatches = testShardsBatchGatewayAllocator.createAndUpdateBatches(testAllocation, false);
    assertEquals("Replica shard should be batched", 1, replicaBatches.size());
    assertEquals(1, testShardsBatchGatewayAllocator.getBatchIdToStoreShardBatch().size());

    ShardsBatchGatewayAllocator.ShardsBatch batch = testShardsBatchGatewayAllocator.getBatchIdToStoreShardBatch()
        .values()
        .iterator()
        .next();
    assertTrue("Batch should contain the replica shard", batch.getBatchedShards().contains(shardId));

    ShardRouting closedReplicaShard = ShardRouting.newUnassigned(
        shardId,
        false,
        RecoverySource.PeerRecoverySource.INSTANCE,
        new UnassignedInfo(
            UnassignedInfo.Reason.INDEX_CLOSED,
            "index closed",
            null,
            0,
            System.nanoTime(),
            System.currentTimeMillis(),
            false,
            UnassignedInfo.AllocationStatus.NO_ATTEMPT,
            Collections.emptySet()
        )
    );

    Metadata closedMetadata = Metadata.builder()
        .put(
            IndexMetadata.builder(shardId.getIndexName())
                .settings(settings(Version.CURRENT))
                .numberOfShards(1)
                .numberOfReplicas(1)
                .state(IndexMetadata.State.CLOSE)
                .putInSyncAllocationIds(0, Sets.newHashSet(primaryShard.allocationId().getId()))
        )
        .build();

    IndexRoutingTable.Builder closedIndexRoutingTable = IndexRoutingTable.builder(shardId.getIndex())
        .addIndexShard(new IndexShardRoutingTable.Builder(shardId).addShard(primaryShard).addShard(closedReplicaShard).build());

    RoutingTable closedRoutingTable = RoutingTable.builder().add(closedIndexRoutingTable).build();

    ClusterState closedClusterState = ClusterState.builder(ClusterName.CLUSTER_NAME_SETTING.getDefault(Settings.EMPTY))
        .metadata(closedMetadata)
        .routingTable(closedRoutingTable)
        .build();

    RoutingAllocation closedAllocation = new RoutingAllocation(
        new AllocationDeciders(Collections.emptyList()),
        new RoutingNodes(closedClusterState, false),
        closedClusterState,
        ClusterInfo.EMPTY,
        SnapshotShardSizeInfo.EMPTY,
        System.nanoTime()
    );

    Set<String> batchesAfterClose = testShardsBatchGatewayAllocator.createAndUpdateBatches(closedAllocation, false);

    if (batchesAfterClose.isEmpty()) {
        assertEquals("Batch should be cleaned up when empty", 0, testShardsBatchGatewayAllocator.getBatchIdToStoreShardBatch().size());
    } else {
        ShardsBatchGatewayAllocator.ShardsBatch batchAfterClose = testShardsBatchGatewayAllocator.getBatchIdToStoreShardBatch()
            .values()
            .iterator()
            .next();
        assertFalse(
            "Batch should not contain the closed index shard after reroute",
            batchAfterClose.getBatchedShards().contains(shardId)
        );
    }
}