java.lang.OutOfMemoryError: Direct buffer memory when enabling logger debugging

Gatling (Open-Source)
1

Hi. This is my first post. I’m very new to Gatling.

I am trying to debug “j.i.IOException: Premature close” by turning on traces.
Anytime I enable http engine traces, I get an OOM stack trace (below) when starting up the simulation.
Has anyone encountered/resolved this problem? If so, please advise.

If it helps, I can include my .scala file. I’ll need to sanitize, but omitted it mainly for brevity.

This is the log line that I turn on in logback.xml

        <!-- uncomment and set to DEBUG to log all failing HTTP requests -->
        <!-- uncomment and set to TRACE to log all HTTP requests -->
        **<logger name="io.gatling.http.engine.response" level="TRACE" />**
...

14:43:06.751 [ERROR] i.g.h.c.i.HttpAppHandler - Fatal error
java.lang.OutOfMemoryError: Direct buffer memory
	at java.base/java.nio.Bits.reserveMemory(Bits.java:175)
	at java.base/java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:118)
	at java.base/java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:317)
	at io.netty.buffer.PoolArena$DirectArena.allocateDirect(PoolArena.java:701)
	at io.netty.buffer.PoolArena$DirectArena.newChunk(PoolArena.java:676)
	at io.netty.buffer.PoolArena.allocateNormal(PoolArena.java:215)
	at io.netty.buffer.PoolArena.tcacheAllocateSmall(PoolArena.java:180)
	at io.netty.buffer.PoolArena.allocate(PoolArena.java:137)
	at io.netty.buffer.PoolArena.allocate(PoolArena.java:129)
	at io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:396)
	at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:188)
	at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:179)
	at io.netty.handler.ssl.SslHandler.allocate(SslHandler.java:2265)
	at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1348)
	at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1246)
	at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1295)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:529)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:468)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800)
	at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:499)
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:397)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:829)

Runtime info:

  • Ubuntu 22.04 LTS (8 dedicated CPU VM with 64GB ram)
  • openjdk version “11.0.19” 2023-04-18
    OpenJDK Runtime Environment (build 11.0.19+7-post-Ubuntu-0ubuntu122.04.1)
    OpenJDK 64-Bit Server VM (build 11.0.19+7-post-Ubuntu-0ubuntu122.04.1, mixed mode, sharing)

java opts (I’ve tried higher/lower, same outcome)
export JAVA_OPTS=‘-Xmx10240m’ (yes, 10Gb)

  • gatling-charts-highcharts-bundle-3.9.5
2

The issue is most likely the other way around: you’re allocating so much of the machine’s native memory for the heap that there’s no more room for the non-heap one.

3

So I changed the JAVA_OPTS down to 528m, and now its working. Thank you! I hope this post helps someone else.