Java tutorial
/* * * Copyright (c) 2014 CA. All rights reserved. * * Licensed 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. * IN NO EVENT WILL CA BE LIABLE TO THE END USER OR ANY THIRD PARTY FOR ANY LOSS * OR DAMAGE, DIRECT OR INDIRECT, FROM THE USE OF THIS MATERIAL, * INCLUDING WITHOUT LIMITATION, LOST PROFITS, BUSINESS INTERRUPTION, GOODWILL, * OR LOST DATA, EVEN IF CA IS EXPRESSLY ADVISED OF SUCH LOSS OR DAMAGE. * */ package com.ca.apm.mongo; import java.util.ArrayList; import java.util.Collection; import java.util.List; import java.util.Properties; import java.util.logging.Logger; import java.util.logging.Level; import org.bson.BasicBSONObject; import com.mongodb.BasicDBList; import com.mongodb.BasicDBObject; import com.mongodb.CommandResult; import com.mongodb.DB; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.MongoClient; public final class ShardCluster extends Topology { public ShardCluster(final Properties props, final String h, final int p, final Logger l) { super(props, h, p, l, ClusterType.SHARDED_CLUSTER); } private String host = dbHost; private int port = dbPort; public void discoverServers(final String nodeType) throws Exception { List<String> shardRouters = null; List<String> shardServers = null; List<String> cfgServers = null; logger.log(Level.FINE, "Shard Cluster Node Type: {0}", nodeType); if ("shardRouter".equals(nodeType)) { shardServers = getShardsFromMongos(host, port); shardRouters = getMongosFromConfig(host, port); cfgServers = getConfigServersFromMongos(host, port); } else if ("shardConfigServer".equals(nodeType)) { shardRouters = getMongosFromConfig(host, port); for (String shardRouter : shardRouters) { MongoServer ms = new MongoServer(shardRouter); cfgServers = getConfigServersFromMongos(ms.getHost(), ms.getPort()); break; } shardServers = getShardsFromConfig(host, port); } else if ("shardMember".equals(nodeType)) { cfgServers = getConfigServersFromShard(host, port); for (String cfgServer : cfgServers) { MongoServer ms = new MongoServer(cfgServer); shardRouters = getMongosFromConfig(ms.getHost(), ms.getPort()); break; } for (String cfgServer : cfgServers) { MongoServer ms = new MongoServer(cfgServer); shardServers = getShardsFromConfig(ms.getHost(), ms.getPort()); break; } } else { throw new RuntimeException("UnKnown Cluster node type!"); } members.addAll(shardRouters); members.addAll(shardServers); members.addAll(cfgServers); } private List<String> getShardsFromMongos(final String host, final int port) throws Exception { final List<String> shardResult = new ArrayList<String>(); final CommandResult cr = dbAdminCmd(host, port, "listShards"); if (cr.ok()) { final BasicDBList shardList = (BasicDBList) cr.get("shards"); for (Object obj : shardList) { final BasicDBObject bdbo = (BasicDBObject) obj; String shards = bdbo.getString("host"); if (shards.indexOf("/") != -1) { final String[] shardMembers = shards.split("/")[1].split(","); for (String member : shardMembers) { final MongoServer ms = new MongoServer(member); shardResult.addAll(discoverReplicas(ms.getHost(), ms.getPort())); } } else { // single node shard shardResult.add(shards); } } } return shardResult; } private List<String> getShardsFromConfig(final String host, final int port) { final List<String> shardList = new ArrayList<String>(); MongoClient dbClient = null; try { dbClient = setupDbClient(host, port); final DB configDB = dbClient.getDB("config"); final DBCursor shardsCursor = configDB.getCollectionFromString("shards").find(); while (shardsCursor.hasNext()) { final DBObject dbo = shardsCursor.next(); String shards = (String) dbo.get("host"); String[] shardMembers = getShardMembers(shards); for (String member : shardMembers) { shardList.add(member); } } } catch (Exception e) { logger.log(Level.WARNING, "Exception getting shards from cfg servers: {0}", e); } finally { if (dbClient != null) { dbClient.close(); } } return shardList; } private List<String> getMongosFromConfig(final String host, final int port) { final List<String> shardRouters = new ArrayList<String>(); MongoClient dbClient = null; try { dbClient = setupDbClient(host, port); final DB configDB = dbClient.getDB("config"); final DBCursor mongosCursor = configDB.getCollectionFromString("mongos").find(); while (mongosCursor.hasNext()) { final DBObject dbo = mongosCursor.next(); final String mongos = (String) dbo.get("_id"); shardRouters.add(mongos); } } catch (Exception e) { logger.log(Level.WARNING, "Exception getting mongos from cfg server(s): {0}", e); } finally { if (dbClient != null) { dbClient.close(); } } return shardRouters; } private List<String> getConfigServersFromMongos(final String host, final int port) throws Exception { final List<String> cfgServers = new ArrayList<String>(); final BasicBSONObject parsed = getParsedCmdLineOpts(host, port); final BasicBSONObject sharding = (BasicBSONObject) parsed.get("sharding"); String cfgServerString; if (sharding != null) cfgServerString = sharding.getString("configDB"); else cfgServerString = (String) parsed.get("configDB"); addCommaSeparatedHosts(cfgServers, cfgServerString); return cfgServers; } private List<String> getConfigServersFromShard(final String host, final int port) throws Exception { final List<String> cfgServers = new ArrayList<String>(); String cHost = host; int cPort = port; final CommandResult isMaster = dbAdminCmd(cHost, cPort, "isMaster"); // we can't run the DB command "shardingState" from a node // which isn't a master. This should only apply to non-primary // replica members, so find the primary and run the command on it. if (!isMaster.getBoolean("ismaster")) { if (isMaster.containsField("primary")) { final String primary = isMaster.getString("primary"); final MongoServer ms = new MongoServer(primary); cHost = ms.getHost(); cPort = ms.getPort(); } } CommandResult shardState = dbAdminCmd(cHost, cPort, "shardingState"); if (shardState.ok()) { final String cfgSrvs = shardState.getString("configServer"); addCommaSeparatedHosts(cfgServers, cfgSrvs); } return cfgServers; } private String[] getShardMembers(final String shardString) { String shards = shardString; if (shards.indexOf("/") != -1) { shards = shards.split("/")[1]; } return shards.split(","); } private void addCommaSeparatedHosts(final Collection<String> c, final String hosts) { if (hosts != null) { for (String host : hosts.split(",")) { c.add(host); } } } private BasicBSONObject getParsedCmdLineOpts(final String host, final int port) throws Exception { BasicBSONObject parsed = null; final CommandResult clOptions = dbAdminCmd(host, port, "getCmdLineOpts"); if (clOptions.ok()) { parsed = (BasicBSONObject) clOptions.get("parsed"); } else { throw new RuntimeException("Failed to get command line options!"); } return parsed; } }