001 /**
002 * Copyright 2005-2014 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.kuali.rice.ksb.messaging;
017
018 import java.io.InterruptedIOException;
019 import java.lang.reflect.Method;
020 import java.lang.reflect.Proxy;
021 import java.net.ConnectException;
022 import java.net.NoRouteToHostException;
023 import java.net.SocketTimeoutException;
024 import java.net.UnknownHostException;
025 import java.util.ArrayList;
026 import java.util.HashSet;
027 import java.util.List;
028 import java.util.Set;
029
030 import org.apache.commons.httpclient.ConnectTimeoutException;
031 import org.apache.commons.httpclient.ConnectionPoolTimeoutException;
032 import org.apache.commons.httpclient.NoHttpResponseException;
033 import org.apache.log4j.Logger;
034 import org.kuali.rice.core.api.util.ClassLoaderUtils;
035 import org.kuali.rice.core.api.util.ContextClassLoaderProxy;
036 import org.kuali.rice.core.api.util.reflect.BaseTargetedInvocationHandler;
037 import org.kuali.rice.ksb.api.KsbApiServiceLocator;
038 import org.kuali.rice.ksb.api.bus.Endpoint;
039 import org.kuali.rice.ksb.api.bus.ServiceConfiguration;
040
041
042
043 public class BusClientFailureProxy extends BaseTargetedInvocationHandler {
044
045 private static final Logger LOG = Logger.getLogger(BusClientFailureProxy.class);
046
047 private final Object failoverLock = new Object();
048
049 private ServiceConfiguration serviceConfiguration;
050
051 // exceptions that will cause this Proxy to remove the service from the bus
052 private static List<Class<?>> serviceRemovalExceptions = new ArrayList<Class<?>>();
053 private static List<Integer> serviceRemovalResponseCodes = new ArrayList<Integer>();
054
055 static {
056 serviceRemovalExceptions.add(NoHttpResponseException.class);
057 serviceRemovalExceptions.add(InterruptedIOException.class);
058 serviceRemovalExceptions.add(UnknownHostException.class);
059 serviceRemovalExceptions.add(NoRouteToHostException.class);
060 serviceRemovalExceptions.add(ConnectTimeoutException.class);
061 serviceRemovalExceptions.add(ConnectionPoolTimeoutException.class);
062 serviceRemovalExceptions.add(ConnectException.class);
063 serviceRemovalExceptions.add(SocketTimeoutException.class);
064 }
065
066 static {
067 serviceRemovalResponseCodes.add(new Integer(404));
068 serviceRemovalResponseCodes.add(new Integer(503));
069 }
070
071 private BusClientFailureProxy(Object target, ServiceConfiguration serviceConfiguration) {
072 super(target);
073 this.serviceConfiguration = serviceConfiguration;
074 }
075
076 public static Object wrap(Object target, ServiceConfiguration serviceConfiguration) {
077 return Proxy.newProxyInstance(ClassLoaderUtils.getDefaultClassLoader(), ContextClassLoaderProxy.getInterfacesToProxy(target), new BusClientFailureProxy(target, serviceConfiguration));
078 }
079
080 protected Object invokeInternal(Object proxyObject, Method method, Object[] params) throws Throwable {
081 Set<ServiceConfiguration> servicesTried = null;
082
083 do {
084 try {
085 return method.invoke(getTarget(), params);
086 } catch (Throwable throwable) {
087 if (isServiceRemovalException(throwable)) {
088 synchronized (failoverLock) {
089 LOG.error("Exception caught accessing remote service " + this.serviceConfiguration.getServiceName() + " at " + this.serviceConfiguration.getEndpointUrl(), throwable);
090 if (servicesTried == null) {
091 servicesTried = new HashSet<ServiceConfiguration>();
092 servicesTried.add(serviceConfiguration);
093 }
094 Object failoverService = null;
095 List<Endpoint> endpoints = KsbApiServiceLocator.getServiceBus().getEndpoints(serviceConfiguration.getServiceName(), serviceConfiguration.getApplicationId());
096 for (Endpoint endpoint : endpoints) {
097 if (!servicesTried.contains(endpoint.getServiceConfiguration())) {
098 failoverService = endpoint.getService();
099 if(Proxy.isProxyClass(failoverService.getClass()) && Proxy.getInvocationHandler(failoverService) instanceof BusClientFailureProxy) {
100 failoverService = ((BusClientFailureProxy)Proxy.getInvocationHandler(failoverService)).getTarget();
101 }
102 servicesTried.add(endpoint.getServiceConfiguration());
103 break; // KULRICE-8728: BusClientFailureProxy doesn't try all endpoint options
104 }
105 }
106 if (failoverService != null) {
107 LOG.info("Refetched replacement service for service " + this.serviceConfiguration.getServiceName() + " at " + this.serviceConfiguration.getEndpointUrl());
108 // as per KULRICE-4287, reassign target to the new service we just fetched, hopefully this one works better!
109 setTarget(failoverService);
110 } else {
111 LOG.error("Didn't find replacement service throwing exception");
112 throw throwable;
113 }
114 }
115 } else {
116 throw throwable;
117 }
118 }
119 } while (true);
120 }
121
122 private static boolean isServiceRemovalException(Throwable throwable) {
123 LOG.info("Checking for Service Removal Exception: " + throwable.getClass().getName());
124 if (serviceRemovalExceptions.contains(throwable.getClass())) {
125 LOG.info("Found a Service Removal Exception: " + throwable.getClass().getName());
126 return true;
127 } else if (throwable instanceof org.kuali.rice.ksb.messaging.HttpException) {
128 org.kuali.rice.ksb.messaging.HttpException httpException = (org.kuali.rice.ksb.messaging.HttpException)throwable;
129 if (serviceRemovalResponseCodes.contains(httpException.getResponseCode())) {
130 LOG.info("Found a Service Removal Exception because of a " + httpException.getResponseCode() + " " + throwable.getClass().getName());
131 return true;
132 }
133 } else if (throwable instanceof org.apache.cxf.transport.http.HTTPException) {
134 org.apache.cxf.transport.http.HTTPException httpException = (org.apache.cxf.transport.http.HTTPException)throwable;
135 if (serviceRemovalResponseCodes.contains(httpException.getResponseCode())) {
136 LOG.info("Found a Service Removal Exception because of a " + httpException.getResponseCode() + " " + throwable.getClass().getName());
137 return true;
138 }
139 }
140 if (throwable.getCause() != null) {
141 LOG.info("Unwrapping Throwable cause to check for service removal exception from: " + throwable.getClass().getName());
142 return isServiceRemovalException(throwable.getCause());
143 }
144 return false;
145 }
146
147 }