HTTP Server Control

HTTP Read / Write buffer : This can controlled via following configuration parameters in your configuration files.

Parameter Name	Description	Default Value
netty.tcp.server.backlog	The maximum queue length for incoming connection indications (a request to connect) is set to the backlog parameter. If a connection indication arrives when the queue is full, the connection is refused.	8192
netty.tcp.server.tcpNoDelay	The value of this socket option is a `Boolean` that represents whether the option is enabled or disabled.	true
netty.tcp.server.sendBufferSize	Set a hint the size of the underlying buffers for outgoing network I/O.	1048576
netty.tcp.server.receiveBufferSize.max	Maximum number of bytes to receive over a TCP connection	1048576
netty.tcp.server.receiveBufferSize.min	Minimum number of bytes to receive over a TCP connection	64
netty.tcp.server.receiveTotalSize.max	Total size in bytes to receive over a TCP connection	1048576
netty.tcp.server.receiveBufferSize.def	Default size in bytes to receive over a TCP connection	65536
netty.tcp.server.writeBufferLowWaterMark	Sets the low water mark of the write buffer. Once the number of bytes queued in the write buffer exceeded the high water mark and then dropped down below this value, Channel.isWritable() will return true again.	32768
netty.tcp.server.writeBufferHighWaterMark	Sets the high water mark of the write buffer. If the number of bytes queued in the write buffer exceeds this value, Channel.isWritable() will start to return `false`.	131072

Example: Here is the configuration setting to receive large data value over HTTP (2MB)

Sample Write Buffer Setting

<netty.tcp.server.receiveTotalSize.max>3048576</netty.tcp.server.receiveTotalSize.max>
<netty.tcp.server.receiveBufferSize.max>2048576</netty.tcp.server.receiveBufferSize.max>
<netty.tcp.server.receiveBufferSize.min>64</netty.tcp.server.receiveBufferSize.min>
<netty.tcp.server.receiveBufferSize.def>65536</netty.tcp.server.receiveBufferSize.def>
<netty.tcp.server.writeBufferLowWaterMark>32768</netty.tcp.server.writeBufferLowWaterMark>
<netty.tcp.server.writeBufferHighWaterMark>3048576</netty.tcp.server.writeBufferHighWaterMark>>

Warning

The default parameter values above are determined by large developer’s community to provide reasonable balance between performance and memory consumption in most if not all real life situations.
Changing them may *significantly degrade* overall engine performance and must be considered only for rapid prototyping, testing or as a very last resort when absolutely no other option is available.
The necessity of increasing maximum buffer sizes beyond default limits usually indicates major application design problems.
You are strongly encouraged to [re]design your application/API properly instead of “quick-n-dirty” fix of increasing buffer size.