Java tutorial
/** * This file is part of Graylog. * * Graylog is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Graylog is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Graylog. If not, see <http://www.gnu.org/licenses/>. */ package org.graylog2.cluster; import com.google.common.collect.Maps; import javax.inject.Inject; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import org.bson.types.ObjectId; import org.graylog2.Configuration; import org.graylog2.database.MongoConnection; import org.graylog2.database.PersistedServiceImpl; import org.graylog2.plugin.database.ValidationException; import org.graylog2.plugin.Tools; import org.graylog2.plugin.system.NodeId; import java.net.URI; import java.util.Map; import java.util.concurrent.TimeUnit; public class NodeServiceImpl extends PersistedServiceImpl implements NodeService { private final long pingTimeout; @Inject public NodeServiceImpl(final MongoConnection mongoConnection, final Configuration configuration) { super(mongoConnection); this.pingTimeout = TimeUnit.MILLISECONDS.toSeconds(configuration.getStaleMasterTimeout()); } @Override public String registerServer(String nodeId, boolean isMaster, URI restTransportUri) { Map<String, Object> fields = Maps.newHashMap(); fields.put("last_seen", Tools.getUTCTimestamp()); fields.put("node_id", nodeId); fields.put("type", Node.Type.SERVER.toString()); fields.put("is_master", isMaster); fields.put("transport_address", restTransportUri.toString()); try { return save(new NodeImpl(fields)); } catch (ValidationException e) { throw new RuntimeException("Validation failed.", e); } } @Override public String registerRadio(String nodeId, String restTransportUri) { Map<String, Object> fields = Maps.newHashMap(); fields.put("last_seen", Tools.getUTCTimestamp()); fields.put("node_id", nodeId); fields.put("type", Node.Type.RADIO.toString()); fields.put("transport_address", restTransportUri); try { return save(new NodeImpl(fields)); } catch (ValidationException e) { throw new RuntimeException("Validation failed.", e); } } @Override public Node byNodeId(String nodeId) throws NodeNotFoundException { DBObject query = new BasicDBObject("node_id", nodeId); DBObject o = findOne(NodeImpl.class, query); if (o == null || !o.containsField("node_id")) { throw new NodeNotFoundException("Unable to find node " + nodeId); } return new NodeImpl((ObjectId) o.get("_id"), o.toMap()); } @Override public Node byNodeId(NodeId nodeId) throws NodeNotFoundException { return byNodeId(nodeId.toString()); } @Override public Map<String, Node> allActive(Node.Type type) { Map<String, Node> nodes = Maps.newHashMap(); BasicDBObject query = new BasicDBObject(); query.put("last_seen", new BasicDBObject("$gte", Tools.getUTCTimestamp() - pingTimeout)); query.put("type", type.toString()); for (DBObject obj : query(NodeImpl.class, query)) { Node node = new NodeImpl((ObjectId) obj.get("_id"), obj.toMap()); String nodeId = (String) obj.get("node_id"); nodes.put(nodeId, node); } return nodes; } @Override public Map<String, Node> allActive() { Map<String, Node> nodes = Maps.newHashMap(); for (Node.Type type : Node.Type.values()) nodes.putAll(allActive(type)); return nodes; } @Override public void dropOutdated() { BasicDBObject query = new BasicDBObject(); query.put("last_seen", new BasicDBObject("$lt", Tools.getUTCTimestamp() - pingTimeout)); destroyAll(NodeImpl.class, query); } /** * Mark this node as alive and probably update some settings that may have changed since last server boot. * * @param isMaster * @param restTransportAddress */ @Override public void markAsAlive(Node node, boolean isMaster, String restTransportAddress) { node.getFields().put("last_seen", Tools.getUTCTimestamp()); node.getFields().put("is_master", isMaster); node.getFields().put("transport_address", restTransportAddress); try { save(node); } catch (ValidationException e) { throw new RuntimeException("Validation failed.", e); } } @Override public void markAsAlive(Node node, boolean isMaster, URI restTransportAddress) { markAsAlive(node, isMaster, restTransportAddress.toString()); } @Override public boolean isOnlyMaster(NodeId nodeId) { BasicDBObject query = new BasicDBObject(); query.put("type", Node.Type.SERVER.toString()); query.put("last_seen", new BasicDBObject("$gte", Tools.getUTCTimestamp() - pingTimeout)); query.put("node_id", new BasicDBObject("$ne", nodeId.toString())); query.put("is_master", true); return query(NodeImpl.class, query).size() == 0; } @Override public boolean isAnyMasterPresent() { BasicDBObject query = new BasicDBObject(); query.put("type", Node.Type.SERVER.toString()); query.put("last_seen", new BasicDBObject("$gte", Tools.getUTCTimestamp() - pingTimeout)); query.put("is_master", true); return query(NodeImpl.class, query).size() > 0; } }