JCBC-2204 Add config option for disabling server-initiated topology change notifications

Motivation
----------
Stopgap while we improve how the SDK handles
server-initiated cluster topology change notifications.

Modifications
-------------
Add client setting `io.configNotifications`.
Default is true (preserve existing behavior).

Change-Id: Ib0d1883aebdbe3b3a773d7280305ecd412d8454c
Reviewed-on: https://review.couchbase.org/c/couchbase-jvm-clients/+/234727
Reviewed-by: Michael Reiche <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: dnault

core-io/src/main/java/com/couchbase/client/core/endpoint/KeyValueEndpoint.java

@@ -128,10 +128,13 @@ private Set<ServerFeature> serverFeatures() {
         ServerFeature.GET_CLUSTER_CONFIG_WITH_KNOWN_VERSION,
         ServerFeature.DUPLEX,
         ServerFeature.DEDUPE_NOT_MY_VBUCKET_CLUSTERMAP,
-        ServerFeature.CLUSTERMAP_CHANGE_NOTIFICATION_BRIEF,
         ServerFeature.SUBDOC_BINARY_XATTR
       );
 
+      if (ctx.environment().ioConfig().configNotifications()) {
+        features.add(ServerFeature.CLUSTERMAP_CHANGE_NOTIFICATION_BRIEF);
+      }
+
       if (ctx.environment().ioConfig().mutationTokensEnabled()) {
         features.add(ServerFeature.MUTATION_SEQNO);
       }

core-io/src/main/java/com/couchbase/client/core/env/IoConfig.java

@@ -48,6 +48,10 @@ public class IoConfig {
   public static final boolean DEFAULT_TCP_KEEPALIVE_ENABLED = true;
   public static final Duration DEFAULT_TCP_KEEPALIVE_TIME = Duration.ofSeconds(60);
   public static final Duration DEFAULT_CONFIG_POLL_INTERVAL = Duration.ofMillis(2500);
+
+  @Stability.Volatile
+  public static final boolean DEFAULT_CONFIG_NOTIFICATIONS = true;
+
   public static final NetworkResolution DEFAULT_NETWORK_RESOLUTION = NetworkResolution.AUTO;
   public static final int DEFAULT_NUM_KV_CONNECTIONS = 1;
   public static final int DEFAULT_MAX_HTTP_CONNECTIONS = AbstractPooledEndpointServiceConfig.DEFAULT_MAX_ENDPOINTS;
@@ -63,6 +67,7 @@ public class IoConfig {
 
   private final boolean mutationTokensEnabled;
   private final Duration configPollInterval;
+  private final boolean configNotifications;
   private final CircuitBreakerConfig kvCircuitBreakerConfig;
   private final CircuitBreakerConfig queryCircuitBreakerConfig;
   private final CircuitBreakerConfig viewCircuitBreakerConfig;
@@ -93,6 +98,7 @@ private IoConfig(Builder builder) {
     configPollInterval = Optional
       .ofNullable(builder.configPollInterval)
       .orElse(DEFAULT_CONFIG_POLL_INTERVAL);
+    configNotifications = builder.configNotifications;
     kvCircuitBreakerConfig = builder.kvCircuitBreakerConfig.build();
     queryCircuitBreakerConfig = builder.queryCircuitBreakerConfig.build();
     viewCircuitBreakerConfig = builder.viewCircuitBreakerConfig.build();
@@ -377,6 +383,11 @@ public Duration configPollInterval() {
     return configPollInterval;
   }
 
+  @Stability.Volatile
+  public boolean configNotifications() {
+    return configNotifications;
+  }
+
   /**
    * Lists the services on which traffic should be captured.
    *
@@ -481,6 +492,7 @@ public static class Builder {
 
     private boolean mutationTokensEnabled = DEFAULT_MUTATION_TOKENS_ENABLED;
     private Duration configPollInterval;
+    private boolean configNotifications = DEFAULT_CONFIG_NOTIFICATIONS;
     private CircuitBreakerConfig.Builder kvCircuitBreakerConfig = CircuitBreakerConfig.builder().enabled(false);
     private CircuitBreakerConfig.Builder queryCircuitBreakerConfig = CircuitBreakerConfig.builder().enabled(false);
     private CircuitBreakerConfig.Builder viewCircuitBreakerConfig = CircuitBreakerConfig.builder().enabled(false);
@@ -576,6 +588,24 @@ public Builder configPollInterval(Duration configPollInterval) {
       return this;
     }
 
+    /**
+     * Call this with a value of false to disable server-initiated
+     * cluster topology change notifications.
+     * <p>
+     * This setting is independent of {@link #configPollInterval(Duration)},
+     * which controls the interval of client-initiated topology change detection.
+     * <p>
+     * Please leave this setting at the default unless advised by
+     * Couchbase Technical Support.
+     * <p>
+     * Defaults to true.
+     */
+    @Stability.Volatile
+    public Builder configNotifications(boolean enabled) {
+      this.configNotifications = enabled;
+      return this;
+    }
+
     /**
      * Configures whether mutation tokens will be returned from the server for all mutation operations.
      *