Remove deprecated xpack.searchable.snapshot.allocate_on_rolling_restart setting (#114202)

The setting was created as an escape-hatch in case #66369 had some unintended side-effects. It has been deprecated since #84959 (8.2.0). --------- Co-authored-by: David Turner <david.turner@elastic.co>

Author: arteam

docs/changelog/114202.yaml

@@ -0,0 +1,14 @@
+pr: 114202
+summary: Remove deprecated `xpack.searchable.snapshot.allocate_on_rolling_restart` setting
+area: Snapshot/Restore
+type: breaking
+issues: []
+breaking:
+ title: Remove deprecated `xpack.searchable.snapshot.allocate_on_rolling_restart` setting
+ area: 'Cluster and node setting'
+ details: >-
+ The `xpack.searchable.snapshot.allocate_on_rolling_restart` setting was created as an escape-hatch just in case
+ relying on the `cluster.routing.allocation.enable=primaries` setting for allocating searchable snapshots during
+ rolling restarts had some unintended side-effects. It has been deprecated since 8.2.0.
+ impact: Remove `xpack.searchable.snapshot.allocate_on_rolling_restart` from your settings if present.
+ notable: false

x-pack/plugin/searchable-snapshots/src/internalClusterTest/java/org/elasticsearch/xpack/searchablesnapshots/allocation/SearchableSnapshotEnableAllocationDeciderIntegTests.java

@@ -15,7 +15,6 @@
 import org.elasticsearch.snapshots.SnapshotId;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.xpack.searchablesnapshots.BaseSearchableSnapshotsIntegTestCase;
-import org.elasticsearch.xpack.searchablesnapshots.allocation.decider.SearchableSnapshotEnableAllocationDecider;
 import org.hamcrest.Matchers;
 
 import java.util.List;
@@ -31,9 +30,7 @@ public void testAllocationDisabled() throws Exception {
  final String restoredIndexName = setupMountedIndex();
  int numPrimaries = getNumShards(restoredIndexName).numPrimaries;
  setEnableAllocation(EnableAllocationDecider.Allocation.PRIMARIES);
- if (randomBoolean()) {
- setAllocateOnRollingRestart(false);
- }
+
  Set<String> indexNodes = internalCluster().nodesInclude(restoredIndexName);
  for (String indexNode : indexNodes) {
  internalCluster().restartNode(indexNode);
@@ -43,16 +40,13 @@ public void testAllocationDisabled() throws Exception {
  .actionGet();
  assertThat(response.getUnassignedShards(), Matchers.equalTo(numPrimaries));
 
- setAllocateOnRollingRestart(true);
+ setEnableAllocation(null);
  ensureGreen(restoredIndexName);
  }
 
  public void testAllocateOnRollingRestartEnabled() throws Exception {
  final String restoredIndexName = setupMountedIndex();
- if (randomBoolean()) {
- setEnableAllocation(EnableAllocationDecider.Allocation.PRIMARIES);
- }
- setAllocateOnRollingRestart(true);
+ setEnableAllocation(null);
  Set<String> indexNodes = internalCluster().nodesInclude(restoredIndexName);
  for (String indexNode : indexNodes) {
  internalCluster().restartNode(indexNode);
@@ -74,14 +68,7 @@ private String setupMountedIndex() throws Exception {
  }
 
  public void setEnableAllocation(EnableAllocationDecider.Allocation allocation) {
- setSetting(EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING, allocation.name());
- }
-
- public void setAllocateOnRollingRestart(boolean allocateOnRollingRestart) {
- setSetting(
- SearchableSnapshotEnableAllocationDecider.SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART,
- Boolean.toString(allocateOnRollingRestart)
- );
+ setSetting(EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING, allocation != null ? allocation.name() : null);
  }
 
  private void setSetting(Setting<?> setting, String value) {

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java

@@ -304,7 +304,6 @@ public List<Setting<?>> getSettings() {
  CacheService.SNAPSHOT_CACHE_SYNC_INTERVAL_SETTING,
  CacheService.SNAPSHOT_CACHE_MAX_FILES_TO_SYNC_AT_ONCE_SETTING,
  CacheService.SNAPSHOT_CACHE_SYNC_SHUTDOWN_TIMEOUT,
- SearchableSnapshotEnableAllocationDecider.SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART,
  BlobStoreCacheMaintenanceService.SNAPSHOT_SNAPSHOT_CLEANUP_INTERVAL_SETTING,
  BlobStoreCacheMaintenanceService.SNAPSHOT_SNAPSHOT_CLEANUP_KEEP_ALIVE_SETTING,
  BlobStoreCacheMaintenanceService.SNAPSHOT_SNAPSHOT_CLEANUP_BATCH_SIZE_SETTING,

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/allocation/decider/SearchableSnapshotEnableAllocationDecider.java

@@ -15,50 +15,26 @@
 import org.elasticsearch.cluster.routing.allocation.decider.Decision;
 import org.elasticsearch.cluster.routing.allocation.decider.EnableAllocationDecider;
 import org.elasticsearch.common.settings.ClusterSettings;
-import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.core.UpdateForV9;
 
 public class SearchableSnapshotEnableAllocationDecider extends AllocationDecider {
 
  static final String NAME = "searchable_snapshots_enable";
 
- /**
- * This setting describes whether searchable snapshots are allocated during rolling restarts. For now, whether a rolling restart is
- * ongoing is determined by cluster.routing.allocation.enable=primaries. Notice that other values for that setting except "all" mean
- * that no searchable snapshots are allocated anyway.
- */
- @UpdateForV9(owner = UpdateForV9.Owner.DISTRIBUTED_COORDINATION)
- // xpack.searchable.snapshot.allocate_on_rolling_restart was only temporary, remove it in the next major
- public static final Setting<Boolean> SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART = Setting.boolSetting(
- "xpack.searchable.snapshot.allocate_on_rolling_restart",
- false,
- Setting.Property.Dynamic,
- Setting.Property.NodeScope,
- Setting.Property.Deprecated
- );
-
  private volatile EnableAllocationDecider.Allocation enableAllocation;
- private volatile boolean allocateOnRollingRestart;
 
  public SearchableSnapshotEnableAllocationDecider(Settings settings, ClusterSettings clusterSettings) {
  this.enableAllocation = EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.get(settings);
- this.allocateOnRollingRestart = SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART.get(settings);
  clusterSettings.addSettingsUpdateConsumer(
  EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING,
  this::setEnableAllocation
  );
- clusterSettings.addSettingsUpdateConsumer(SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART, this::setAllocateOnRollingRestart);
  }
 
  private void setEnableAllocation(EnableAllocationDecider.Allocation allocation) {
  this.enableAllocation = allocation;
  }
 
- private void setAllocateOnRollingRestart(boolean allocateOnRollingRestart) {
- this.allocateOnRollingRestart = allocateOnRollingRestart;
- }
-
  @Override
  public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation) {
  return canAllocate(shardRouting, allocation);
@@ -73,25 +49,14 @@ public Decision canAllocate(ShardRouting shardRouting, RoutingAllocation allocat
  final IndexMetadata indexMetadata = allocation.metadata().getIndexSafe(shardRouting.index());
  if (indexMetadata.isSearchableSnapshot()) {
  EnableAllocationDecider.Allocation enableAllocationCopy = this.enableAllocation;
- boolean allocateOnRollingRestartCopy = this.allocateOnRollingRestart;
  if (enableAllocationCopy == EnableAllocationDecider.Allocation.PRIMARIES) {
- if (allocateOnRollingRestartCopy == false) {
- return allocation.decision(
- Decision.NO,
- NAME,
- "no allocations of searchable snapshots allowed during rolling restart due to [%s=%s] and [%s=false]",
- EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey(),
- enableAllocationCopy,
- SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART.getKey()
- );
- } else {
- return allocation.decision(
- Decision.YES,
- NAME,
- "allocate on rolling restart enabled [%s=true]",
- SEARCHABLE_SNAPSHOTS_ALLOCATE_ON_ROLLING_RESTART.getKey()
- );
- }
+ return allocation.decision(
+ Decision.NO,
+ NAME,
+ "no allocations of searchable snapshots allowed during rolling restart due to [%s=%s]",
+ EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey(),
+ enableAllocationCopy
+ );
  } else {
  return allocation.decision(
  Decision.YES,