org.apache.brooklyn.entity.nosql.mongodb.ReplicaSetConfig 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 org.apache.brooklyn.entity.nosql.mongodb;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import java.util.Iterator;

import org.apache.brooklyn.core.location.access.BrooklynAccessUtils;
import org.bson.BSONObject;
import org.bson.BasicBSONObject;
import org.bson.types.BasicBSONList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Optional;
import com.google.common.net.HostAndPort;

/**
 * Simplifies the creation of configuration objects for Mongo DB replica sets.
 * 
 * A configuration object is structured like this:
 * 
 * {
 *    "_id" : "replica-set-name",
 *     "version" : 3,
 *    "members" : [
 *        { "_id" : 0, "host" : "Sams.local:27017" },
 *        { "_id" : 1, "host" : "Sams.local:27018" },
 *        { "_id" : 2, "host" : "Sams.local:27019" }
 *    ]
 * }
 * 
 * To add or remove servers to a replica set you must redefine this configuration
 * (run replSetReconfig on the primary) with the new members
 * list and the version updated.
 */
public class ReplicaSetConfig {

    private static final Logger LOG = LoggerFactory.getLogger(ReplicaSetConfig.class);
    static final int MAXIMUM_REPLICA_SET_SIZE = 12;
    static final int MAXIMUM_VOTING_MEMBERS = 7;

    private Optional primary = Optional.absent();

    private String name;
    private Integer version;
    BasicBSONList members;

    public ReplicaSetConfig(String name) {
        this(name, new BasicBSONList());
    }

    public ReplicaSetConfig(String name, BasicBSONList existingMembers) {
        this.name = name;
        this.members = existingMembers;
        this.version = 1;
    }

    /**
     * Creates a configuration with the given name.
     */
    public static ReplicaSetConfig builder(String name) {
        return new ReplicaSetConfig(name);
    }

    /**
     * Creates a configuration from an existing configuration.
     * 
     * Automatically increments the replica set's version number.
     */
    public static ReplicaSetConfig fromExistingConfig(BSONObject config) {
        checkNotNull(config);
        checkArgument(config.containsField("_id"), "_id missing from replica set config");
        checkArgument(config.containsField("version"), "version missing from replica set config");
        checkArgument(config.containsField("members"), "members missing from replica set config");

        String name = (String) config.get("_id");
        Integer version = (Integer) config.get("version");
        BasicBSONList members = (BasicBSONList) config.get("members");

        return new ReplicaSetConfig(name, members).version(++version);
    }

    /**
     * Sets the version of the configuration. The version number must increase as the replica set changes.
     */
    public ReplicaSetConfig version(Integer version) {
        this.version = version;
        return this;
    }

    /**
     * Notes the primary member of the replica. Primary members will always be voting members.
     */
    public ReplicaSetConfig primary(HostAndPort primary) {
        this.primary = Optional.of(primary);
        return this;
    }

    /**
     * Adds a new member to the replica set config using {@link MongoDBServer#HOSTNAME} and {@link MongoDBServer#PORT}
     * for hostname and port. Doesn't attempt to check that the id is free.
     */
    public ReplicaSetConfig member(MongoDBServer server, Integer id) {
        // TODO: Switch to SUBNET_HOSTNAME and there should be no need for a Brooklyn accessible
        // address. It will require modification to MongoDBClientSupport, though, since it sets
        // the primary to the host/port accessible from Brooklyn.
        HostAndPort hap = BrooklynAccessUtils.getBrooklynAccessibleAddress(server, server.getAttribute(MongoDBServer.PORT));
        return member(hap.getHostText(), hap.getPort(), id);
    }

    /**
     * Adds a new member to the replica set config using the given {@link HostAndPort} for hostname and port.
     * Doesn't attempt to check that the id is free.
     */
    public ReplicaSetConfig member(HostAndPort address, Integer id) {
        return member(address.getHostText(), address.getPort(), id);
    }

    /**
     * Adds a new member to the replica set config with the given hostname, port and id. Doesn't attempt to check
     * that the id is free.
     */
    public ReplicaSetConfig member(String hostname, Integer port, Integer id) {
        if (members.size() == MAXIMUM_REPLICA_SET_SIZE) {
            throw new IllegalStateException(String.format(
                    "Replica set {} exceeds maximum size of {} with addition of member at {}:{}",
                    new Object[]{name, MAXIMUM_REPLICA_SET_SIZE, hostname, port}));
        }
        BasicBSONObject member = new BasicBSONObject();
        member.put("_id", id);
        member.put("host", String.format("%s:%s", hostname, port));
        members.add(member);
        return this;
    }

    /** Removes the first entity using {@link MongoDBServer#HOSTNAME} and {@link MongoDBServer#PORT}. */
    public ReplicaSetConfig remove(MongoDBServer server) {
        HostAndPort hap = BrooklynAccessUtils.getBrooklynAccessibleAddress(server, server.getAttribute(MongoDBServer.PORT));
        return remove(hap.getHostText(), hap.getPort());
    }

    /** Removes the first entity with host and port matching the given address. */
    public ReplicaSetConfig remove(HostAndPort address) {
        return remove(address.getHostText(), address.getPort());
    }

    /**
     * Removes the first entity with the given hostname and port from the list of members
     */
    public ReplicaSetConfig remove(String hostname, Integer port) {
        String host = String.format("%s:%s", hostname, port);
        Iterator