ControllableConnectionFactory.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.zookeeper.server.controller;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.IOException;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import org.apache.zookeeper.server.NIOServerCnxn;
import org.apache.zookeeper.server.NIOServerCnxnFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Extension of NIOServerCnxnFactory which can inject changes per controller commands.
* Similar extensions can implement on top of NettyServerCnxnFactory as well.
*/
@SuppressFBWarnings(value = "SWL_SLEEP_WITH_LOCK_HELD", justification = "no dead lock")
public class ControllableConnectionFactory extends NIOServerCnxnFactory {
private static final Logger LOG = LoggerFactory.getLogger(ControllableConnectionFactory.class);
private long responseDelayInMs = 0;
private long remainingRequestsToFail = 0;
private long remainingResponsesToHold = 0;
public ControllableConnectionFactory() {
}
@Override
protected NIOServerCnxn createConnection(SocketChannel sock, SelectionKey sk, SelectorThread selectorThread)
throws IOException {
return new ControllableConnection(zkServer, sock, sk, this, selectorThread);
}
/**
* Called by the connection to delay processing requests from the client.
*/
public synchronized void delayRequestIfNeeded() {
try {
if (responseDelayInMs > 0) {
Thread.sleep(responseDelayInMs);
}
} catch (InterruptedException ex) {
LOG.warn("Interrupted while delaying requests", ex);
}
}
/**
* Check if we should fail the next incoming request.
* If so, decrement the remaining requests to fail.
*/
public synchronized boolean shouldFailNextRequest() {
if (remainingRequestsToFail == 0) {
return false;
}
// Value < 0 indicates fail all requests.
if (remainingRequestsToFail > 0) {
remainingRequestsToFail--;
}
return true;
}
/**
* Check if we should send a response to the latest processed request (true),
* or eat the response to mess with the client (false).
* If so, decrement the remaining requests to eat.
*/
public synchronized boolean shouldSendResponse() {
if (remainingResponsesToHold == 0) {
return true;
}
// Value < 0 indicates hold all the responses.
if (remainingResponsesToHold > 0) {
remainingResponsesToHold--;
}
return false;
}
public synchronized void delayResponses(long delayInMs) {
if (delayInMs < 0) {
throw new IllegalArgumentException("delay must be non-negative");
}
responseDelayInMs = delayInMs;
}
public synchronized void resetBadBehavior() {
responseDelayInMs = 0;
remainingRequestsToFail = 0;
remainingResponsesToHold = 0;
}
public synchronized void failAllFutureRequests() {
this.remainingRequestsToFail = -1;
}
public synchronized void failFutureRequests(long requestsToFail) {
this.remainingRequestsToFail = requestsToFail;
}
public synchronized void holdAllFutureResponses() {
this.remainingResponsesToHold = -1;
}
public synchronized void holdFutureResponses(long requestsToHold) {
this.remainingResponsesToHold = requestsToHold;
}
}