/*
* 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.cassandra.transport;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.jboss.netty.channel.ChannelHandler;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicLong;
/**
* {@link SimpleChannelUpstreamHandler} implementation which allows to limit the number of concurrent
* connections to the Server. Be aware this <strong>MUST</strong> be shared between all child channels.
*/
@ChannelHandler.Sharable
final class ConnectionLimitHandler extends SimpleChannelUpstreamHandler
{
private static final Logger logger = LoggerFactory.getLogger(ConnectionLimitHandler.class);
private final ConcurrentMap<InetAddress, AtomicLong> connectionsPerClient = new ConcurrentHashMap<>();
private final AtomicLong counter = new AtomicLong(0);
@Override
public void channelOpen(ChannelHandlerContext ctx, ChannelStateEvent event) throws Exception
{
final long count = counter.incrementAndGet();
long limit = DatabaseDescriptor.getNativeTransportMaxConcurrentConnections();
// Setting the limit to -1 disables it.
if(limit < 0)
{
limit = Long.MAX_VALUE;
}
if (count > limit)
{
// The decrement will be done in channelClosed(...)
logger.warn("Exceeded maximum native connection limit of {} by using {} connections", limit, count);
ctx.getChannel().close();
}
else
{
long perIpLimit = DatabaseDescriptor.getNativeTransportMaxConcurrentConnectionsPerIp();
if (perIpLimit > 0)
{
InetAddress address = ((InetSocketAddress) ctx.getChannel().getRemoteAddress()).getAddress();
AtomicLong perIpCount = connectionsPerClient.get(address);
if (perIpCount == null)
{
perIpCount = new AtomicLong(0);
AtomicLong old = connectionsPerClient.putIfAbsent(address, perIpCount);
if (old != null)
{
perIpCount = old;
}
}
if (perIpCount.incrementAndGet() > perIpLimit)
{
// The decrement will be done in channelClosed(...)
logger.warn("Exceeded maximum native connection limit per ip of {} by using {} connections", perIpLimit, perIpCount);
ctx.getChannel().close();
return;
}
}
super.channelOpen(ctx, event);
}
}
@Override
public void channelClosed(ChannelHandlerContext ctx, ChannelStateEvent event) throws Exception
{
counter.decrementAndGet();
InetAddress address = ((InetSocketAddress) ctx.getChannel().getRemoteAddress()).getAddress();
AtomicLong count = connectionsPerClient.get(address);
if (count != null)
{
if (count.decrementAndGet() <= 0)
{
connectionsPerClient.remove(address);
}
}
super.channelClosed(ctx, event);
}
}