ege-st commented on code in PR #11496: URL: https://github.com/apache/pinot/pull/11496#discussion_r1322165856
########## pinot-core/src/main/java/org/apache/pinot/core/transport/DirectOOMHandler.java: ########## @@ -0,0 +1,100 @@ +/** + * 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.pinot.core.transport; + +import io.netty.channel.Channel; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInboundHandlerAdapter; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicBoolean; +import org.apache.pinot.spi.exception.QueryCancelledException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +// Handling netty direct memory OOM. In this case there is a great chance that multiple channels are receiving +// large data tables from servers concurrently. We want to close all channels to servers to proactively release +// the direct memory, because the execution of netty threads can deadlock in allocating direct memory, in which case +// no one will reach channelRead0. +public class DirectOOMHandler extends ChannelInboundHandlerAdapter { + private static final Logger LOGGER = LoggerFactory.getLogger(DataTableHandler.class); + private static final AtomicBoolean DIRECT_OOM_SHUTTING_DOWN = new AtomicBoolean(false); + private final QueryRouter _queryRouter; + private final ServerRoutingInstance _serverRoutingInstance; + private final ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> _serverToChannelMap; + + public void setSilentShutDown() { + _silentShutDown = true; + } + + private volatile boolean _silentShutDown = false; + + public DirectOOMHandler(QueryRouter queryRouter, ServerRoutingInstance serverRoutingInstance, + ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> serverToChannelMap) { + _queryRouter = queryRouter; + _serverRoutingInstance = serverRoutingInstance; + _serverToChannelMap = serverToChannelMap; + } + + @Override + public void channelInactive(ChannelHandlerContext ctx) { + // if we are shutting down channels due to direct memory OOM, we short circuit the channel inactive + if (_silentShutDown) { + return; + } + ctx.fireChannelInactive(); + } + + @Override + public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { + // catch direct memory oom here + if (cause instanceof OutOfMemoryError && cause.getMessage().contains("Direct buffer")) { + // only one thread can get here and do the shutdown + if (DIRECT_OOM_SHUTTING_DOWN.compareAndSet(false, true)) { + try { + LOGGER.error("Closing ALL channels to servers, as we are running out of direct memory " + + "while receiving response from {}", _serverRoutingInstance, cause); + // close all channels to servers + ctx.channel().close(); + _serverToChannelMap.keySet().forEach(serverRoutingInstance -> { Review Comment: My rough understanding (correct me if I'm wrong) is that this is not an atomic operation, so another part of Pinot could be adding/updating this map as we iterate over it. Question is: what happens to this close channel process if another thread is adding servers to the router? ########## pinot-core/src/main/java/org/apache/pinot/core/transport/DirectOOMHandler.java: ########## @@ -0,0 +1,100 @@ +/** + * 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.pinot.core.transport; + +import io.netty.channel.Channel; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInboundHandlerAdapter; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicBoolean; +import org.apache.pinot.spi.exception.QueryCancelledException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +// Handling netty direct memory OOM. In this case there is a great chance that multiple channels are receiving +// large data tables from servers concurrently. We want to close all channels to servers to proactively release +// the direct memory, because the execution of netty threads can deadlock in allocating direct memory, in which case +// no one will reach channelRead0. +public class DirectOOMHandler extends ChannelInboundHandlerAdapter { + private static final Logger LOGGER = LoggerFactory.getLogger(DataTableHandler.class); + private static final AtomicBoolean DIRECT_OOM_SHUTTING_DOWN = new AtomicBoolean(false); + private final QueryRouter _queryRouter; + private final ServerRoutingInstance _serverRoutingInstance; + private final ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> _serverToChannelMap; + + public void setSilentShutDown() { + _silentShutDown = true; + } + + private volatile boolean _silentShutDown = false; + + public DirectOOMHandler(QueryRouter queryRouter, ServerRoutingInstance serverRoutingInstance, + ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> serverToChannelMap) { + _queryRouter = queryRouter; + _serverRoutingInstance = serverRoutingInstance; + _serverToChannelMap = serverToChannelMap; + } + + @Override + public void channelInactive(ChannelHandlerContext ctx) { + // if we are shutting down channels due to direct memory OOM, we short circuit the channel inactive + if (_silentShutDown) { Review Comment: Is it necessary to have the `_silentShutdown` property? Couldn't we just use `DIRECT_OOM_SHUTTING_DOWN` to check if the routing table is going through a restart operation? ########## pinot-core/src/main/java/org/apache/pinot/core/transport/DirectOOMHandler.java: ########## @@ -0,0 +1,100 @@ +/** + * 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.pinot.core.transport; + +import io.netty.channel.Channel; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInboundHandlerAdapter; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicBoolean; +import org.apache.pinot.spi.exception.QueryCancelledException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +// Handling netty direct memory OOM. In this case there is a great chance that multiple channels are receiving +// large data tables from servers concurrently. We want to close all channels to servers to proactively release +// the direct memory, because the execution of netty threads can deadlock in allocating direct memory, in which case +// no one will reach channelRead0. +public class DirectOOMHandler extends ChannelInboundHandlerAdapter { + private static final Logger LOGGER = LoggerFactory.getLogger(DataTableHandler.class); + private static final AtomicBoolean DIRECT_OOM_SHUTTING_DOWN = new AtomicBoolean(false); + private final QueryRouter _queryRouter; + private final ServerRoutingInstance _serverRoutingInstance; + private final ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> _serverToChannelMap; + + public void setSilentShutDown() { + _silentShutDown = true; + } + + private volatile boolean _silentShutDown = false; + + public DirectOOMHandler(QueryRouter queryRouter, ServerRoutingInstance serverRoutingInstance, + ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> serverToChannelMap) { + _queryRouter = queryRouter; + _serverRoutingInstance = serverRoutingInstance; + _serverToChannelMap = serverToChannelMap; + } + + @Override + public void channelInactive(ChannelHandlerContext ctx) { + // if we are shutting down channels due to direct memory OOM, we short circuit the channel inactive + if (_silentShutDown) { + return; + } + ctx.fireChannelInactive(); + } + + @Override + public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { + // catch direct memory oom here + if (cause instanceof OutOfMemoryError && cause.getMessage().contains("Direct buffer")) { + // only one thread can get here and do the shutdown + if (DIRECT_OOM_SHUTTING_DOWN.compareAndSet(false, true)) { + try { + LOGGER.error("Closing ALL channels to servers, as we are running out of direct memory " + + "while receiving response from {}", _serverRoutingInstance, cause); + // close all channels to servers + ctx.channel().close(); + _serverToChannelMap.keySet().forEach(serverRoutingInstance -> { + Channel channel = _serverToChannelMap.get(serverRoutingInstance)._channel; + if (channel != null) { + DirectOOMHandler directOOMHandler = channel.pipeline().get(DirectOOMHandler.class); + if (directOOMHandler != null) { Review Comment: This should never be `null` correct? So if it is, we should log some kind of error message to indicate that something went very wrong. In fact, I would argue that `directOOMHandler` is added to every channel pipeline that we create, so it should never be `null` which means that if it is, then something unknown is modifying our channel pipelines, and if that's the case the state of the server is no longer trustworthy or recoverable and we should fault. ########## pinot-core/src/main/java/org/apache/pinot/core/transport/DirectOOMHandler.java: ########## @@ -0,0 +1,100 @@ +/** + * 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.pinot.core.transport; + +import io.netty.channel.Channel; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInboundHandlerAdapter; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicBoolean; +import org.apache.pinot.spi.exception.QueryCancelledException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +// Handling netty direct memory OOM. In this case there is a great chance that multiple channels are receiving +// large data tables from servers concurrently. We want to close all channels to servers to proactively release +// the direct memory, because the execution of netty threads can deadlock in allocating direct memory, in which case +// no one will reach channelRead0. +public class DirectOOMHandler extends ChannelInboundHandlerAdapter { + private static final Logger LOGGER = LoggerFactory.getLogger(DataTableHandler.class); + private static final AtomicBoolean DIRECT_OOM_SHUTTING_DOWN = new AtomicBoolean(false); + private final QueryRouter _queryRouter; + private final ServerRoutingInstance _serverRoutingInstance; + private final ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> _serverToChannelMap; + + public void setSilentShutDown() { + _silentShutDown = true; + } + + private volatile boolean _silentShutDown = false; + + public DirectOOMHandler(QueryRouter queryRouter, ServerRoutingInstance serverRoutingInstance, + ConcurrentHashMap<ServerRoutingInstance, ServerChannels.ServerChannel> serverToChannelMap) { + _queryRouter = queryRouter; + _serverRoutingInstance = serverRoutingInstance; + _serverToChannelMap = serverToChannelMap; + } + + @Override + public void channelInactive(ChannelHandlerContext ctx) { + // if we are shutting down channels due to direct memory OOM, we short circuit the channel inactive + if (_silentShutDown) { + return; + } + ctx.fireChannelInactive(); + } + + @Override + public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { + // catch direct memory oom here + if (cause instanceof OutOfMemoryError && cause.getMessage().contains("Direct buffer")) { + // only one thread can get here and do the shutdown + if (DIRECT_OOM_SHUTTING_DOWN.compareAndSet(false, true)) { + try { + LOGGER.error("Closing ALL channels to servers, as we are running out of direct memory " + + "while receiving response from {}", _serverRoutingInstance, cause); + // close all channels to servers + ctx.channel().close(); + _serverToChannelMap.keySet().forEach(serverRoutingInstance -> { + Channel channel = _serverToChannelMap.get(serverRoutingInstance)._channel; + if (channel != null) { Review Comment: What does it mean if `channel` is `null` at this point? Does it mean that something else closed it or that the server was removed from the routing table for another reason? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
