com.datastax.oss.driver.internal.core.loadbalancing.helper.MandatoryLocalDcHelper Maven / Gradle / Ivy
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.oss.driver.internal.core.loadbalancing.helper;
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.metadata.Node;
import com.datastax.oss.driver.internal.core.context.InternalDriverContext;
import com.datastax.oss.driver.internal.core.metadata.DefaultNode;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.UUID;
import net.jcip.annotations.ThreadSafe;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* An implementation of {@link LocalDcHelper} that fetches the user-supplied datacenter, if any,
* from the programmatic configuration API, or else, from the driver configuration. If no local
* datacenter is explicitly defined, this implementation will consider two distinct situations:
*
*
* - If no explicit contact points were provided, this implementation will infer the local
* datacenter from the implicit contact point (localhost).
*
- If explicit contact points were provided however, this implementation will throw {@link
* IllegalStateException}.
*
*/
@ThreadSafe
public class MandatoryLocalDcHelper extends OptionalLocalDcHelper {
private static final Logger LOG = LoggerFactory.getLogger(MandatoryLocalDcHelper.class);
public MandatoryLocalDcHelper(
@NonNull InternalDriverContext context,
@NonNull DriverExecutionProfile profile,
@NonNull String logPrefix) {
super(context, profile, logPrefix);
}
/** @return The local datacenter; always present. */
@NonNull
@Override
public Optional discoverLocalDc(@NonNull Map nodes) {
Optional optionalLocalDc = super.discoverLocalDc(nodes);
if (optionalLocalDc.isPresent()) {
return optionalLocalDc;
}
Set contactPoints = context.getMetadataManager().getContactPoints();
if (context.getMetadataManager().wasImplicitContactPoint()) {
// We only allow automatic inference of the local DC in this specific case
assert contactPoints.size() == 1;
Node contactPoint = contactPoints.iterator().next();
String localDc = contactPoint.getDatacenter();
if (localDc != null) {
LOG.debug(
"[{}] Local DC set from implicit contact point {}: {}",
logPrefix,
contactPoint,
localDc);
return Optional.of(localDc);
} else {
throw new IllegalStateException(
"The local DC could not be inferred from implicit contact point, please set it explicitly (see "
+ DefaultDriverOption.LOAD_BALANCING_LOCAL_DATACENTER.getPath()
+ " in the config, or set it programmatically with SessionBuilder.withLocalDatacenter)");
}
} else {
throw new IllegalStateException(
"Since you provided explicit contact points, the local DC must be explicitly set (see "
+ DefaultDriverOption.LOAD_BALANCING_LOCAL_DATACENTER.getPath()
+ " in the config, or set it programmatically with SessionBuilder.withLocalDatacenter). "
+ "Current contact points are: "
+ formatNodesAndDcs(contactPoints)
+ ". Current DCs in this cluster are: "
+ formatDcs(nodes.values()));
}
}
}