Add optional fallback for ControlConnection#reconnect()

Adds an experimental option to allow `ControlConnection` to try
reconnecting to the original contact points held by `MetadataManager`,
in case of getting empty query plan from the load balancing policy.

core/src/main/java/com/datastax/oss/driver/api/core/config/DefaultDriverOption.java

@@ -668,6 +668,15 @@ public enum DefaultDriverOption implements DriverOption {
  */
  CONTROL_CONNECTION_AGREEMENT_WARN("advanced.control-connection.schema-agreement.warn-on-failure"),
 
+ /**
+ * Whether to forcibly add original contact points held by MetadataManager to the reconnection
+ * plan, in case there is no live nodes available according to LBP. Experimental.
+ *
+ * <p>Value-type: boolean
+ */
+ CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS(
+ "advanced.control-connection.reconnection.fallback-to-original-contacts"),
+
  /**
  * Whether `Session.prepare` calls should be sent to all nodes in the cluster.
  *

core/src/main/java/com/datastax/oss/driver/api/core/config/OptionsMap.java

@@ -360,6 +360,7 @@ protected static void fillWithDriverDefaults(OptionsMap map) {
  map.put(TypedDriverOption.CONTROL_CONNECTION_AGREEMENT_INTERVAL, Duration.ofMillis(200));
  map.put(TypedDriverOption.CONTROL_CONNECTION_AGREEMENT_TIMEOUT, Duration.ofSeconds(10));
  map.put(TypedDriverOption.CONTROL_CONNECTION_AGREEMENT_WARN, true);
+ map.put(TypedDriverOption.CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS, false);
  map.put(TypedDriverOption.PREPARE_ON_ALL_NODES, true);
  map.put(TypedDriverOption.REPREPARE_ENABLED, true);
  map.put(TypedDriverOption.REPREPARE_CHECK_SYSTEM_TABLE, false);

core/src/main/java/com/datastax/oss/driver/api/core/config/TypedDriverOption.java

@@ -566,6 +566,10 @@ public String toString() {
  public static final TypedDriverOption<Boolean> CONTROL_CONNECTION_AGREEMENT_WARN =
  new TypedDriverOption<>(
  DefaultDriverOption.CONTROL_CONNECTION_AGREEMENT_WARN, GenericType.BOOLEAN);
+ /** Whether to forcibly try original contacts if no live nodes are available */
+ public static final TypedDriverOption<Boolean> CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS =
+ new TypedDriverOption<>(
+ DefaultDriverOption.CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS, GenericType.BOOLEAN);
  /** Whether `Session.prepare` calls should be sent to all nodes in the cluster. */
  public static final TypedDriverOption<Boolean> PREPARE_ON_ALL_NODES =
  new TypedDriverOption<>(DefaultDriverOption.PREPARE_ON_ALL_NODES, GenericType.BOOLEAN);

core/src/main/java/com/datastax/oss/driver/internal/core/control/ControlConnection.java

@@ -336,7 +336,7 @@ private void init(
 
  private CompletionStage<Boolean> reconnect() {
  assert adminExecutor.inEventLoop();
- Queue<Node> nodes = context.getLoadBalancingPolicyWrapper().newQueryPlan();
+ Queue<Node> nodes = context.getLoadBalancingPolicyWrapper().newControlReconnectionQueryPlan();
  CompletableFuture<Boolean> result = new CompletableFuture<>();
  connect(
  nodes,

core/src/main/java/com/datastax/oss/driver/internal/core/metadata/LoadBalancingPolicyWrapper.java

@@ -17,6 +17,7 @@
  */
 package com.datastax.oss.driver.internal.core.metadata;
 
+import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
 import com.datastax.oss.driver.api.core.config.DriverExecutionProfile;
 import com.datastax.oss.driver.api.core.loadbalancing.LoadBalancingPolicy;
 import com.datastax.oss.driver.api.core.loadbalancing.NodeDistance;
@@ -165,6 +166,24 @@ public Queue<Node> newQueryPlan() {
  return newQueryPlan(null, DriverExecutionProfile.DEFAULT_NAME, null);
  }
 
+ @NonNull
+ public Queue<Node> newControlReconnectionQueryPlan() {
+ // First try the original way
+ Queue<Node> regularQueryPlan = newQueryPlan();
+ if (!regularQueryPlan.isEmpty()) return regularQueryPlan;
+
+ if (context
+ .getConfig()
+ .getDefaultProfile()
+ .getBoolean(DefaultDriverOption.CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS)) {
+ List<Node> nodes = new ArrayList<>(context.getMetadataManager().getContactPoints());
+ Collections.shuffle(nodes);
+ return new ConcurrentLinkedQueue<>(nodes);
+ } else {
+ return regularQueryPlan;
+ }
+ }
+
  // when it comes in from the outside
  private void onNodeStateEvent(NodeStateEvent event) {
  eventFilter.accept(event);

core/src/main/java/com/datastax/oss/driver/internal/core/metadata/SchemaAgreementChecker.java

@@ -174,7 +174,7 @@ private void completeOrReschedule(Set<UUID> uuids, Throwable error) {
  f -> {
  if (!f.isSuccess()) {
  LOG.debug(
- "[{}] Error while rescheduling schema agreement, completing now (false)",
+ "[{}] listesner Error while rescheduling schema agreement, completing now (false)",
  logPrefix,
  f.cause());
  }

core/src/main/resources/reference.conf

@@ -2113,6 +2113,17 @@ datastax-java-driver {
  # Overridable in a profile: no
  warn-on-failure = true
  }
+
+ reconnection {
+ # Whether to forcibly add original contact points held by MetadataManager to the reconnection plan,
+ # in case there is no live nodes available according to LBP.
+ # Experimental.
+ #
+ # Required: yes
+ # Modifiable at runtime: yes, the new value will be used for checks issued after the change.
+ # Overridable in a profile: no
+ fallback-to-original-contacts = false
+ }
  }
 
  advanced.prepared-statements {

core/src/test/java/com/datastax/oss/driver/internal/core/control/ControlConnectionTestBase.java

@@ -132,6 +132,11 @@ public void setup() {
  when(defaultProfile.getBoolean(DefaultDriverOption.CONNECTION_WARN_INIT_ERROR))
  .thenReturn(false);
 
+ when(context.getConfig()).thenReturn(config);
+ when(config.getDefaultProfile()).thenReturn(defaultProfile);
+ when(defaultProfile.getBoolean(DefaultDriverOption.CONTROL_CONNECTION_RECONNECT_CONTACT_POINTS))
+ .thenReturn(false);
+
  controlConnection = new ControlConnection(context);
  }