現象
執行load命令時，java程序異常退出，mycat日誌報錯：
02/28 18:59:20.494 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 8192
02/28 18:59:20.494 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 16384
02/28 18:59:20.494 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 32768
02/28 18:59:20.494 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 65536
02/28 18:59:20.494 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 131072
02/28 18:59:20.495 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 262144
02/28 18:59:20.495 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 524288
02/28 18:59:20.496 WARN [$_NIOREACTOR-7-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 1048576
02/28 18:59:21.453 INFO [$_NIOREACTOR-7-RW] (AbstractConnection.java:458) -close connection,reason:Bad: java.lang.OutOfMemoryError: Direct buffer memory ,ServerConnection [id=26528912, schema=nifa_db, host=127.0.0.1, user=nifa_db_user,txIsolation=2, autocommit=true, schema=nifa_db]
02/28 18:59:21.453 ERROR [$_NIOREACTOR-7-RW] (NIOReactor.java:130) -caught err:
java.lang.OutOfMemoryError: Direct buffer memory
at java.nio.Bits.reserveMemory(Bits.java:694)
at java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:123)
at java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:311)
at sun.nio.ch.Util.getTemporaryDirectBuffer(Util.java:241)
at sun.nio.ch.IOUtil.read(IOUtil.java:195)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
at org.opencloudb.net.NIOSocketWR.asynRead(NIOSocketWR.java:185)
at org.opencloudb.net.AbstractConnection.asynRead(AbstractConnection.java:274)
at org.opencloudb.net.NIOReactor$RW.run(NIOReactor.java:100)
at java.lang.Thread.run(Thread.java:748)
tail: mycat.log: file truncated
嘗試解決1：增大jvm參數
更改mycat的啓動腳本startup_nowrap.sh，原配置：
JAVA_OPTS="-server -Xms8G -Xmx8G -XX:MaxPermSize=64M -XX:+AggressiveOpts -XX:MaxDirectMemorySize=2G"
修改爲：
JAVA_OPTS="-server -Xms8G -Xmx8G -XX:MaxPermSize=640M -XX:+AggressiveOpts -XX:MaxDirectMemorySize=6G"
跟蹤1：仍有警告
再次執行load infile，mycat日誌：
02/28 19:02:26.879 INFO [$_NIOREACTOR-14-RW] (FrontendAuthenticator.java:193) -ServerConnection [id=9, schema=nifa_db, host=127.0.0.1, user=nifa_db_user,txIsolation=2, autocommit=true, schema=nifa_db]'nifa_db_user' login success
02/28 19:02:26.894 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 8192
02/28 19:02:26.895 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 16384
02/28 19:02:26.895 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 32768
02/28 19:02:26.896 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 65536
02/28 19:02:26.896 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 131072
02/28 19:02:26.896 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 262144
02/28 19:02:26.897 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 524288
02/28 19:02:26.898 WARN [$_NIOREACTOR-14-RW] (BufferPool.java:187) -allocate buffer size large than default chunksize:4096 he want 1048576
嘗試解決2：調整mycat配置參數
server.xml中，將默認processorBufferChunk修改爲：
<property name="processorBufferChunk">4096000</property>
跟蹤2：完美解決沒有警告
至此該問題完美解決。