[DRILL-1976] Possible Memory Leak in drill jdbc client when dealing with wide columns (5000 chars long)

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Component/s: Execution - Flow
• Assignee: Rahul Kumar Challapalli
• Reporter: Rahul Kumar Challapalli
• Created: 10/Jan/15 00:46
• Updated: 03/Oct/15 00:14
• Resolved: 18/Sep/15 02:00

Description

git.commit.id.abbrev=b491cdb

I am seeing an execution failure when I execute the same query multiple times (<10). The data file contains 9 columns out of which 7 are wide strings (4000-5000 chars long)

select ws.*, sub.str_var str_var1 from widestrings ws INNER JOIN (select str_var, max(tinyint_var) max_ti from widestrings group by str_var) sub on ws.tinyint_var = sub.max_ti

Below are my memory settings :

DRILL_MAX_DIRECT_MEMORY="32G"
DRILL_MAX_HEAP="4G"

Error From the JDBC client

select ws.*, sub.str_var str_var1 from widestrings ws INNER JOIN (select str_var, max(tinyint_var) max_ti from widestrings group by str_var) sub on ws.tinyint_var = sub.max_ti

Exception in pipeline.  Closing channel between local /10.10.100.190:38179 and remote qa-node191.qa.lab/10.10.100.191:31010
io.netty.handler.codec.DecoderException: java.lang.OutOfMemoryError: Direct buffer memory
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:151)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
	at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:787)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:130)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
	at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.OutOfMemoryError: Direct buffer memory
	at java.nio.Bits.reserveMemory(Bits.java:658)
	at java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:123)
	at java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:306)
	at io.netty.buffer.PoolArena$DirectArena.newUnpooledChunk(PoolArena.java:443)
	at io.netty.buffer.PoolArena.allocateHuge(PoolArena.java:187)
	at io.netty.buffer.PoolArena.allocate(PoolArena.java:165)
	at io.netty.buffer.PoolArena.reallocate(PoolArena.java:280)
	at io.netty.buffer.PooledByteBuf.capacity(PooledByteBuf.java:110)
	at io.netty.buffer.AbstractByteBuf.ensureWritable(AbstractByteBuf.java:251)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:849)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:841)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:831)
	at io.netty.buffer.WrappedByteBuf.writeBytes(WrappedByteBuf.java:600)
	at io.netty.buffer.UnsafeDirectLittleEndian.writeBytes(UnsafeDirectLittleEndian.java:25)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:144)
	... 13 more
Channel closed between local /10.10.100.190:38179 and remote qa-node191.qa.lab/10.10.100.191:31010
Channel is closed, discarding remaining 255231 byte(s) in buffer.

The logs