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 beforeRefresh(String resourceId, String owner, int holdSec) {
  79
  80         TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  81
  82         return(tLock.refresh(holdSec) ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  83     }
  84
  85         @Override
  86         public OperResult beforeUnlock(String resourceId, String owner) {
  87                 TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  88
  89                 return(tLock.unlock() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  90         }
  91
  92         @Override
  93         public OperResult beforeIsLockedBy(String resourceId, String owner) {
  94                 TargetLock tLock = new TargetLock(resourceId, uuid, owner, dataSource);
  95
  96         return(tLock.isActive() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
  97         }
  98
  99         @Override
 100         public OperResult beforeIsLocked(String resourceId) {
 101                 TargetLock tLock = new TargetLock(resourceId, uuid, "dummyOwner", dataSource);
 102
 103         return(tLock.isLocked() ? OperResult.OPER_ACCEPTED : OperResult.OPER_DENIED);
 104         }
 105
 106         @Override
 107         public boolean afterStart(PolicyEngine engine) {
 108
 109                 try {
 110                         this.lockProps = new DistributedLockingProperties(SystemPersistence.manager.getProperties(DistributedLockingFeature.CONFIGURATION_PROPERTIES_NAME));
 111                         this.dataSource = makeDataSource();
 112                 } catch (PropertyException e) {
 113                         logger.error("DistributedLockingFeature feature properies have not been loaded", e);
 114                         throw new DistributedLockingFeatureException(e);
 115                 } catch(InterruptedException e) {
 116             logger.error("DistributedLockingFeature failed to create data source", e);
 117                     Thread.currentThread().interrupt();
 118             throw new DistributedLockingFeatureException(e);
 119         } catch(Exception e) {
 120             logger.error("DistributedLockingFeature failed to create data source", e);
 121             throw new DistributedLockingFeatureException(e);
 122                 }
 123
 124                 cleanLockTable();
 125
 126                 return false;
 127         }
 128
 129         /**
 130          * @return a new, pooled data source
 131          * @throws Exception
 132          */
 133         private BasicDataSource makeDataSource() throws Exception {
 134         Properties props = new Properties();
 135         props.put("driverClassName", lockProps.getDbDriver());
 136         props.put("url", lockProps.getDbUrl());
 137         props.put("username", lockProps.getDbUser());
 138         props.put("password", lockProps.getDbPwd());
 139         props.put("testOnBorrow", "true");
 140         props.put("poolPreparedStatements", "true");
 141
 142         // additional properties are listed in the GenericObjectPool API
 143
 144         return BasicDataSourceFactory.createDataSource(props);
 145     }
 146
 147     /**
 148          * This method kills the heartbeat thread and calls refreshLockTable which removes
 149          * any records from the db where the current host is the owner.
 150          */
 151         @Override
 152         public boolean beforeShutdown(PolicyEngine engine) {
 153                 cleanLockTable();
 154                 return false;
 155         }
 156
 157         /**
 158          * This method removes all records owned by the current host from the db.
 159          */
 160         private void cleanLockTable() {
 161
 162             try (Connection conn = dataSource.getConnection();
 163                         PreparedStatement statement = conn.prepareStatement(
 164                                         "DELETE FROM pooling.locks WHERE host = ? OR expirationTime < now()");
 165                 ){
 166
 167                                 statement.setString(1, uuid.toString());
 168                                 statement.executeUpdate();
 169
 170                 } catch (SQLException e) {
 171                         logger.error("error in refreshLockTable()", e);
 172                 }
 173
 174         }
 175 }