/*
* Copyright 2004,2005 The Apache Software Foundation.
*
* 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.
*/
package org.apache.axis2.clustering.tribes;
import org.apache.axis2.clustering.ClusteringFault;
import org.apache.axis2.clustering.Member;
import org.apache.axis2.clustering.MembershipScheme;
import org.apache.axis2.clustering.control.wka.JoinGroupCommand;
import org.apache.axis2.clustering.control.wka.MemberListCommand;
import org.apache.axis2.clustering.control.wka.RpcMembershipRequestHandler;
import org.apache.axis2.description.Parameter;
import org.apache.axis2.util.Utils;
import org.apache.catalina.tribes.Channel;
import org.apache.catalina.tribes.ManagedChannel;
import org.apache.catalina.tribes.group.Response;
import org.apache.catalina.tribes.group.RpcChannel;
import org.apache.catalina.tribes.group.interceptors.OrderInterceptor;
import org.apache.catalina.tribes.group.interceptors.StaticMembershipInterceptor;
import org.apache.catalina.tribes.group.interceptors.TcpFailureDetector;
import org.apache.catalina.tribes.group.interceptors.TcpPingInterceptor;
import org.apache.catalina.tribes.membership.StaticMember;
import org.apache.catalina.tribes.transport.ReceiverBase;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
/**
* Implementation of the WKA(well-known address) based membership scheme. In this scheme,
* membership is discovered using a few well-known members (who run at well-known IP addresses)
*/
public class WkaBasedMembershipScheme implements MembershipScheme {
private static final Log log = LogFactory.getLog(WkaBasedMembershipScheme.class);
/**
* The Tribes channel
*/
private final ManagedChannel channel;
private final MembershipManager primaryMembershipManager;
private final List<MembershipManager> applicationDomainMembershipManagers;
private StaticMembershipInterceptor staticMembershipInterceptor;
private final Map<String, Parameter> parameters;
/**
* The loadBalancerDomain to which the members belong to
*/
private final byte[] localDomain;
/**
* The static(well-known) members
*/
private final List<Member> members;
/**
* The mode in which this member operates such as "loadBalance" or "application"
*/
private final OperationMode mode;
private final boolean atmostOnceMessageSemantics;
private final boolean preserverMsgOrder;
public WkaBasedMembershipScheme(ManagedChannel channel,
OperationMode mode,
List<MembershipManager> applicationDomainMembershipManagers,
MembershipManager primaryMembershipManager,
Map<String, Parameter> parameters,
byte[] domain,
List<Member> members,
boolean atmostOnceMessageSemantics,
boolean preserverMsgOrder) {
this.channel = channel;
this.mode = mode;
this.applicationDomainMembershipManagers = applicationDomainMembershipManagers;
this.primaryMembershipManager = primaryMembershipManager;
this.parameters = parameters;
this.localDomain = domain;
this.members = members;
this.atmostOnceMessageSemantics = atmostOnceMessageSemantics;
this.preserverMsgOrder = preserverMsgOrder;
}
/**
* Configure the membership related to the WKA based scheme
*
* @throws org.apache.axis2.clustering.ClusteringFault
* If an error occurs while configuring this scheme
*/
public void init() throws ClusteringFault {
addInterceptors();
configureStaticMembership();
}
private void configureStaticMembership() throws ClusteringFault {
channel.setMembershipService(new WkaMembershipService(primaryMembershipManager));
StaticMember localMember = new StaticMember();
primaryMembershipManager.setLocalMember(localMember);
ReceiverBase receiver = (ReceiverBase) channel.getChannelReceiver();
// ------------ START: Configure and add the local member ---------------------
Parameter localHost = getParameter(TribesConstants.LOCAL_MEMBER_HOST);
String host;
if (localHost != null) {
host = ((String) localHost.getValue()).trim();
} else { // In cases where the localhost needs to be automatically figured out
try {
try {
host = Utils.getIpAddress();
} catch (SocketException e) {
String msg = "Could not get local IP address";
log.error(msg, e);
throw new ClusteringFault(msg, e);
}
} catch (Exception e) {
String msg = "Could not get the localhost name";
log.error(msg, e);
throw new ClusteringFault(msg, e);
}
}
receiver.setAddress(host);
try {
localMember.setHostname(host);
} catch (IOException e) {
String msg = "Could not set the local member's name";
log.error(msg, e);
throw new ClusteringFault(msg, e);
}
Parameter localPort = getParameter(TribesConstants.LOCAL_MEMBER_PORT);
int port;
try {
if (localPort != null) {
port = Integer.parseInt(((String) localPort.getValue()).trim());
port = getLocalPort(new ServerSocket(), localMember.getHostname(), port, 4000, 100);
} else { // In cases where the localport needs to be automatically figured out
port = getLocalPort(new ServerSocket(), localMember.getHostname(), -1, 4000, 100);
}
} catch (IOException e) {
String msg =
"Could not allocate the specified port or a port in the range 4000-4100 " +
"for local host " + localMember.getHostname() +
". Check whether the IP address specified or inferred for the local " +
"member is correct.";
log.error(msg, e);
throw new ClusteringFault(msg, e);
}
byte[] payload = "ping".getBytes();
localMember.setPayload(payload);
receiver.setPort(port);
localMember.setPort(port);
localMember.setDomain(localDomain);
staticMembershipInterceptor.setLocalMember(localMember);
// ------------ END: Configure and add the local member ---------------------
// ------------ START: Add other members ---------------------
for (Member member : members) {
StaticMember tribesMember;
try {
tribesMember = new StaticMember(member.getHostName(), member.getPort(),
0, payload);
} catch (IOException e) {
String msg = "Could not add static member " +
member.getHostName() + ":" + member.getPort();
log.error(msg, e);
throw new ClusteringFault(msg, e);
}
// Do not add the local member to the list of members
if (!(Arrays.equals(localMember.getHost(), tribesMember.getHost()) &&
localMember.getPort() == tribesMember.getPort())) {
tribesMember.setDomain(localDomain);
// We will add the member even if it is offline at this moment. When the
// member comes online, it will be detected by the GMS
staticMembershipInterceptor.addStaticMember(tribesMember);
primaryMembershipManager.addWellKnownMember(tribesMember);
if (canConnect(member)) {
primaryMembershipManager.memberAdded(tribesMember);
log.info("Added static member " + TribesUtil.getName(tribesMember));
} else {
log.info("Could not connect to member " + TribesUtil.getName(tribesMember));
}
}
}
}
/**
* Before adding a static member, we will try to verify whether we can connect to it
*
* @param member The member whose connectvity needs to be verified
* @return true, if the member can be contacted; false, otherwise.
*/
private boolean canConnect(org.apache.axis2.clustering.Member member) {
for (int retries = 5; retries > 0; retries--) {
try {
InetAddress addr = InetAddress.getByName(member.getHostName());
SocketAddress sockaddr = new InetSocketAddress(addr,
member.getPort());
new Socket().connect(sockaddr, 500);
return true;
} catch (IOException e) {
String msg = e.getMessage();
if (msg.indexOf("Connection refused") == -1 && msg.indexOf("connect timed out") == -1) {
log.error("Cannot connect to member " +
member.getHostName() + ":" + member.getPort(), e);
}
}
}
return false;
}
protected int getLocalPort(ServerSocket socket, String hostname,
int preferredPort, int portstart, int retries) throws IOException {
if (preferredPort != -1) {
try {
return getLocalPort(socket, hostname, preferredPort);
} catch (IOException ignored) {
// Fall through and try a default port
}
}
InetSocketAddress addr = null;
if (retries > 0) {
try {
return getLocalPort(socket, hostname, portstart);
} catch (IOException x) {
retries--;
if (retries <= 0) {
log.error("Unable to bind server socket to:" + addr + " throwing error.");
throw x;
}
portstart++;
try {
Thread.sleep(50);
} catch (InterruptedException ignored) {
ignored.printStackTrace();
}
getLocalPort(socket, hostname, portstart, retries, -1);
}
}
return portstart;
}
private int getLocalPort(ServerSocket socket, String hostname, int port) throws IOException {
InetSocketAddress addr;
addr = new InetSocketAddress(hostname, port);
socket.bind(addr);
log.info("Receiver Server Socket bound to:" + addr);
socket.setSoTimeout(5);
socket.close();
try {
Thread.sleep(100);
} catch (InterruptedException ignored) {
ignored.printStackTrace();
}
return port;
}
/**
* Add ChannelInterceptors. The order of the interceptors that are added will depend on the
* membership management scheme
*/
private void addInterceptors() {
if (log.isDebugEnabled()) {
log.debug("Adding Interceptors...");
}
TcpPingInterceptor tcpPingInterceptor = new TcpPingInterceptor();
tcpPingInterceptor.setInterval(10000);
channel.addInterceptor(tcpPingInterceptor);
if (log.isDebugEnabled()) {
log.debug("Added TCP Ping Interceptor");
}
// Add a reliable failure detector
TcpFailureDetector tcpFailureDetector = new TcpFailureDetector();
// tcpFailureDetector.setPrevious(dfi); //TODO: check this
tcpFailureDetector.setReadTestTimeout(120000);
tcpFailureDetector.setConnectTimeout(180000);
channel.addInterceptor(tcpFailureDetector);
if (log.isDebugEnabled()) {
log.debug("Added TCP Failure Detector");
}
// Add the NonBlockingCoordinator.
// channel.addInterceptor(new Axis2Coordinator(membershipListener));
staticMembershipInterceptor = new StaticMembershipInterceptor();
staticMembershipInterceptor.setLocalMember(primaryMembershipManager.getLocalMember());
primaryMembershipManager.setStaticMembershipInterceptor(staticMembershipInterceptor);
channel.addInterceptor(staticMembershipInterceptor);
if (log.isDebugEnabled()) {
log.debug("Added Static Membership Interceptor");
}
channel.getMembershipService().setDomain(localDomain);
mode.addInterceptors(channel);
if (atmostOnceMessageSemantics) {
// Add a AtMostOnceInterceptor to support at-most-once message processing semantics
AtMostOnceInterceptor atMostOnceInterceptor = new AtMostOnceInterceptor();
atMostOnceInterceptor.setOptionFlag(TribesConstants.AT_MOST_ONCE_OPTION);
channel.addInterceptor(atMostOnceInterceptor);
if (log.isDebugEnabled()) {
log.debug("Added At-most-once Interceptor");
}
}
if (preserverMsgOrder) {
// Add the OrderInterceptor to preserve sender ordering
OrderInterceptor orderInterceptor = new OrderInterceptor();
orderInterceptor.setOptionFlag(TribesConstants.MSG_ORDER_OPTION);
channel.addInterceptor(orderInterceptor);
if (log.isDebugEnabled()) {
log.debug("Added Message Order Interceptor");
}
}
}
/**
* JOIN the group and get the member list
*
* @throws ClusteringFault If an error occurs while joining the group
*/
public void joinGroup() throws ClusteringFault {
// Have multiple RPC channels with multiple RPC request handlers for each localDomain
// This is needed only when this member is running as a load balancer
for (MembershipManager appDomainMembershipManager : applicationDomainMembershipManagers) {
appDomainMembershipManager.setStaticMembershipInterceptor(staticMembershipInterceptor);
// Create an RpcChannel for each localDomain
String domain = new String(appDomainMembershipManager.getDomain());
RpcChannel rpcMembershipChannel =
new RpcChannel(TribesUtil.getRpcMembershipChannelId(appDomainMembershipManager.getDomain()),
channel,
new RpcMembershipRequestHandler(appDomainMembershipManager,
this));
appDomainMembershipManager.setRpcMembershipChannel(rpcMembershipChannel);
if (log.isDebugEnabled()) {
log.debug("Created RPC Membership Channel for application domain " + domain);
}
}
// Create a Membership channel for handling membership requests
RpcChannel rpcMembershipChannel =
new RpcChannel(TribesUtil.getRpcMembershipChannelId(localDomain),
channel, new RpcMembershipRequestHandler(primaryMembershipManager,
this));
if (log.isDebugEnabled()) {
log.debug("Created primary membership channel " + new String(localDomain));
}
primaryMembershipManager.setRpcMembershipChannel(rpcMembershipChannel);
// Send JOIN message to a WKA member
if (primaryMembershipManager.getMembers().length > 0) {
log.info("Sending JOIN message to WKA members...");
org.apache.catalina.tribes.Member[] wkaMembers = primaryMembershipManager.getMembers(); // The well-known members
/*try {
Thread.sleep(3000); // Wait for sometime so that the WKA members can receive the MEMBER_LIST message, if they have just joined the group
} catch (InterruptedException ignored) {
}*/ //TODO: #### Need to double check whether this sleep is necessary
Response[] responses = null;
do {
try {
responses = rpcMembershipChannel.send(wkaMembers,
new JoinGroupCommand(),
RpcChannel.ALL_REPLY,
Channel.SEND_OPTIONS_ASYNCHRONOUS |
TribesConstants.MEMBERSHIP_MSG_OPTION,
10000);
if (responses.length == 0) {
try {
if (log.isDebugEnabled()) {
log.debug("No responses received");
}
Thread.sleep(500);
} catch (InterruptedException ignored) {
}
}
} catch (Exception e) {
String msg = "Error occurred while trying to send JOIN request to WKA members";
log.error(msg, e);
wkaMembers = primaryMembershipManager.getMembers();
if (wkaMembers.length == 0) {
log.warn("There are no well-known members");
break;
}
}
// TODO: If we do not get a response within some time, try to recover from this fault
}
while (responses == null || responses.length == 0); // Wait until we've received at least one response
for (Response response : responses) {
MemberListCommand command = (MemberListCommand) response.getMessage();
command.setMembershipManager(primaryMembershipManager);
command.execute(null); // Set the list of current members
// If the WKA member is not part of this group, remove it
if (!TribesUtil.areInSameDomain(response.getSource(),
primaryMembershipManager.getLocalMember())) {
primaryMembershipManager.memberDisappeared(response.getSource());
if (log.isDebugEnabled()) {
log.debug("Removed member " + TribesUtil.getName(response.getSource()) +
" since it does not belong to the local domain " +
new String(primaryMembershipManager.getLocalMember().getDomain()));
}
}
}
}
}
/**
* When a JOIN message is received from some other member, it is notified using this method,
* so that membership scheme specific processing can be carried out
*
* @param member The member who just joined
*/
public void processJoin(org.apache.catalina.tribes.Member member) {
mode.notifyMemberJoin(member);
}
public Parameter getParameter(String name) {
return parameters.get(name);
}
}