gerrit.onap Code Review - policy/drools-pdp.git/blob

   1 /*
   2  * ============LICENSE_START=======================================================
   3  * feature-distributed-locking
   4  * ================================================================================
   5  * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20 package org.onap.policy.distributed.locking;
  21
  22 import java.sql.Connection;
  23 import java.sql.PreparedStatement;
  24 import java.sql.SQLException;
  25 import java.util.Properties;
  26 import java.util.UUID;
  27 import org.apache.commons.dbcp2.BasicDataSource;
  28 import org.apache.commons.dbcp2.BasicDataSourceFactory;
  29 import org.onap.policy.common.utils.properties.exception.PropertyException;
  30 import org.onap.policy.drools.core.lock.PolicyResourceLockFeatureAPI;
  31 import org.onap.policy.drools.features.PolicyEngineFeatureAPI;
  32 import org.onap.policy.drools.persistence.SystemPersistence;
  33 import org.onap.policy.drools.system.PolicyEngine;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 public class DistributedLockingFeature implements PolicyEngineFeatureAPI, PolicyResourceLockFeatureAPI {
  38
  39         /**
  40          * Logger instance
  41          */
  42         private static final Logger logger = LoggerFactory.getLogger(DistributedLockingFeature.class);
  43
  44         /**
  45          * Properties Configuration Name
  46          */
  47         public static final String CONFIGURATION_PROPERTIES_NAME = "feature-distributed-locking";
  48
  49         /**
  50          * Properties for locking feature
  51          */
  52         private DistributedLockingProperties lockProps;
  53
  54         /**
  55          * Data source used to connect to the DB containing locks.
  56          */
  57         private BasicDataSource dataSource;
  58
  59         /**
  60          * UUID
  61          */
  62         private static final UUID uuid = UUID.randomUUID();
  63
  64         @Override
  65         public int getSequenceNumber() {
  66         return 1000;
  67         }
  68
  69         @Override
  70     public OperResult beforeLock(String resourceId, String owner, int holdSec) {
  71
  72                 TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  73
  74         return(tLock.lock(holdSec) ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  75         }
  76
  77         @Override
  78         public OperResult beforeUnlock(String resourceId, String owner) {
  79                 TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  80
  81                 return(tLock.unlock() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  82         }
  83
  84         @Override
  85         public OperResult beforeIsLockedBy(String resourceId, String owner) {
  86                 TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  87
  88         return(tLock.isActive() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  89         }
  90
  91         @Override
  92         public OperResult beforeIsLocked(String resourceId) {
  93                 TargetLock tLock = new TargetLock(resourceId, uuid, "dummyOwner", dataSource);
  94
  95         return(tLock.isLocked() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  96         }
  97
  98         @Override
  99         public boolean afterStart(PolicyEngine engine) {
 100
 101                 try {
 102                         this.lockProps = new DistributedLockingProperties(SystemPersistence.manager.getProperties(DistributedLockingFeature.CONFIGURATION_PROPERTIES_NAME));
 103                         this.dataSource = makeDataSource();
 104                 } catch (PropertyException e) {
 105                         logger.error("DistributedLockingFeature feature properies have not been loaded", e);
 106                         throw new DistributedLockingFeatureException(e);
 107                 } catch(InterruptedException e) {
 108             logger.error("DistributedLockingFeature failed to create data source", e);
 109                     Thread.currentThread().interrupt();
 110             throw new DistributedLockingFeatureException(e);
 111         } catch(Exception e) {
 112             logger.error("DistributedLockingFeature failed to create data source", e);
 113             throw new DistributedLockingFeatureException(e);
 114                 }
 115
 116                 cleanLockTable();
 117
 118                 return false;
 119         }
 120
 121         /**
 122          * @return a new, pooled data source
 123          * @throws Exception
 124          */
 125         private BasicDataSource makeDataSource() throws Exception {
 126         Properties props = new Properties();
 127         props.put("driverClassName", lockProps.getDbDriver());
 128         props.put("url", lockProps.getDbUrl());
 129         props.put("username", lockProps.getDbUser());
 130         props.put("password", lockProps.getDbPwd());
 131         props.put("testOnBorrow", "true");
 132         props.put("poolPreparedStatements", "true");
 133
 134         // additional properties are listed in the GenericObjectPool API
 135
 136         return BasicDataSourceFactory.createDataSource(props);
 137     }
 138
 139     /**
 140          * This method kills the heartbeat thread and calls refreshLockTable which removes
 141          * any records from the db where the current host is the owner.
 142          */
 143         @Override
 144         public boolean beforeShutdown(PolicyEngine engine) {
 145                 cleanLockTable();
 146                 return false;
 147         }
 148
 149         /**
 150          * This method removes all records owned by the current host from the db.
 151          */
 152         private void cleanLockTable() {
 153
 154             try (Connection conn = dataSource.getConnection();
 155                         PreparedStatement statement = conn.prepareStatement(
 156                                         "DELETE FROM pooling.locks WHERE host = ? OR expirationTime < now()");
 157                 ){
 158
 159                                 statement.setString(1, uuid.toString());
 160                                 statement.executeUpdate();
 161
 162                 } catch (SQLException e) {
 163                         logger.error("error in refreshLockTable()", e);
 164                 }
 165
 166         }
 167 }