StaticMembershipInterceptor.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.catalina.tribes.group.interceptors;
import java.util.ArrayList;
import java.util.Arrays;
import org.apache.catalina.tribes.Channel;
import org.apache.catalina.tribes.ChannelException;
import org.apache.catalina.tribes.ChannelInterceptor;
import org.apache.catalina.tribes.ChannelMessage;
import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.group.AbsoluteOrder;
import org.apache.catalina.tribes.group.ChannelInterceptorBase;
import org.apache.catalina.tribes.io.ChannelData;
import org.apache.catalina.tribes.io.XByteBuffer;
import org.apache.catalina.tribes.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
public class StaticMembershipInterceptor extends ChannelInterceptorBase
implements StaticMembershipInterceptorMBean {
private static final Log log = LogFactory.getLog(StaticMembershipInterceptor.class);
protected static final StringManager sm =
StringManager.getManager(StaticMembershipInterceptor.class);
protected static final byte[] MEMBER_START = new byte[] {
76, 111, 99, 97, 108, 32, 83, 116, 97, 116, 105, 99, 77, 101, 109, 98, 101, 114, 32, 78,
111, 116, 105, 102, 105, 99, 97, 116, 105, 111, 110, 32, 68, 97, 116, 97};
protected static final byte[] MEMBER_STOP = new byte[] {
76, 111, 99, 97, 108, 32, 83, 116, 97, 116, 105, 99, 77, 101, 109, 98, 101, 114, 32, 83,
104, 117, 116, 100, 111, 119, 110, 32, 68, 97, 116, 97};
protected final ArrayList<Member> members = new ArrayList<>();
protected Member localMember = null;
public StaticMembershipInterceptor() {
super();
}
public void addStaticMember(Member member) {
synchronized (members) {
if (!members.contains(member)) {
members.add(member);
}
}
}
public void removeStaticMember(Member member) {
synchronized (members) {
if (members.contains(member)) {
members.remove(member);
}
}
}
public void setLocalMember(Member member) {
this.localMember = member;
localMember.setLocal(true);
}
@Override
public void messageReceived(ChannelMessage msg) {
if (msg.getMessage().getLength() == MEMBER_START.length &&
Arrays.equals(MEMBER_START, msg.getMessage().getBytes())) {
// receive member start
Member member = getMember(msg.getAddress());
if (member != null) {
super.memberAdded(member);
}
} else if (msg.getMessage().getLength() == MEMBER_STOP.length &&
Arrays.equals(MEMBER_STOP, msg.getMessage().getBytes())) {
// receive member shutdown
Member member = getMember(msg.getAddress());
if (member != null) {
try {
member.setCommand(Member.SHUTDOWN_PAYLOAD);
super.memberDisappeared(member);
} finally {
member.setCommand(new byte[0]);
}
}
} else {
super.messageReceived(msg);
}
}
/**
* has members
*/
@Override
public boolean hasMembers() {
return super.hasMembers() || (members.size()>0);
}
/**
* Get all current cluster members
* @return all members or empty array
*/
@Override
public Member[] getMembers() {
if ( members.size() == 0 ) {
return super.getMembers();
} else {
synchronized (members) {
Member[] others = super.getMembers();
Member[] result = new Member[members.size() + others.length];
for (int i = 0; i < others.length; i++) {
result[i] = others[i];
}
for (int i = 0; i < members.size(); i++) {
result[i + others.length] = members.get(i);
}
AbsoluteOrder.absoluteOrder(result);
return result;
}//sync
}//end if
}
/**
* @param mbr Member
* @return Member
*/
@Override
public Member getMember(Member mbr) {
if ( members.contains(mbr) ) {
return members.get(members.indexOf(mbr));
} else {
return super.getMember(mbr);
}
}
/**
* Return the member that represents this node.
*
* @return Member
*/
@Override
public Member getLocalMember(boolean incAlive) {
if (this.localMember != null ) {
return localMember;
} else {
return super.getLocalMember(incAlive);
}
}
/**
* {@inheritDoc}
* <p>
* Sends notifications upwards.
*/
@Override
public void start(int svc) throws ChannelException {
if ( (Channel.SND_RX_SEQ&svc)==Channel.SND_RX_SEQ ) {
super.start(Channel.SND_RX_SEQ);
}
if ( (Channel.SND_TX_SEQ&svc)==Channel.SND_TX_SEQ ) {
super.start(Channel.SND_TX_SEQ);
}
final ChannelInterceptorBase base = this;
for (final Member member : members) {
Thread t = new Thread() {
@Override
public void run() {
base.memberAdded(member);
if (getfirstInterceptor().getMember(member) != null) {
sendLocalMember(new Member[]{member});
}
}
};
t.start();
}
super.start(svc & (~Channel.SND_RX_SEQ) & (~Channel.SND_TX_SEQ));
// check required interceptors
TcpFailureDetector failureDetector = null;
TcpPingInterceptor pingInterceptor = null;
ChannelInterceptor prev = getPrevious();
while (prev != null) {
if (prev instanceof TcpFailureDetector ) {
failureDetector = (TcpFailureDetector) prev;
}
if (prev instanceof TcpPingInterceptor) {
pingInterceptor = (TcpPingInterceptor) prev;
}
prev = prev.getPrevious();
}
if (failureDetector == null) {
log.warn(sm.getString("staticMembershipInterceptor.no.failureDetector"));
}
if (pingInterceptor == null) {
log.warn(sm.getString("staticMembershipInterceptor.no.pingInterceptor"));
}
}
/**
* {@inheritDoc}
* <p>
* Sends local member shutdown.
*/
@Override
public void stop(int svc) throws ChannelException {
// Sends local member shutdown.
Member[] members = getfirstInterceptor().getMembers();
sendShutdown(members);
super.stop(svc);
}
protected void sendLocalMember(Member[] members) {
try {
sendMemberMessage(members, MEMBER_START);
} catch (ChannelException cx) {
log.warn(sm.getString("staticMembershipInterceptor.sendLocalMember.failed"),cx);
}
}
protected void sendShutdown(Member[] members) {
try {
sendMemberMessage(members, MEMBER_STOP);
} catch (ChannelException cx) {
log.warn(sm.getString("staticMembershipInterceptor.sendShutdown.failed"),cx);
}
}
protected ChannelInterceptor getfirstInterceptor() {
ChannelInterceptor result = null;
ChannelInterceptor now = this;
do {
result = now;
now = now.getPrevious();
} while (now.getPrevious() != null);
return result;
}
protected void sendMemberMessage(Member[] members, byte[] message) throws ChannelException {
if ( members == null || members.length == 0 ) {
return;
}
ChannelData data = new ChannelData(true);
data.setAddress(getLocalMember(false));
data.setTimestamp(System.currentTimeMillis());
data.setOptions(getOptionFlag());
data.setMessage(new XByteBuffer(message, false));
super.sendMessage(members, data, null);
}
}