【ActiveMQ Tuning】Optimizing the Protocols

标签：ActiveMQ 性能优化

Overview：协议优化可以在不同的协议层，如下所示

TCP transport（TCP传输）：一般而言，通过增加TCP层的Buffer大小是可以改善TCP层的性能。

Socket buffer size -默认的TCP Socket buffer的大小是64KB。这个设计只是适合最初的TCP协议，这个大小对于当初的猫（modern）网络而言是最合适的。下面的经验可以用于估算出合适的TCP socket buffer的大小。

Buffer size = BandWidth（带宽） X Round-Trip-Time（往返时延）

Round-Trip-Time指的是从TCP发送一个包到接收到这个包的确认的时长（Ping的时间），典型的做法是加倍Socket buffer的大小到128K。

如例：

tcp://hostA:61617?socketBufferSize=131072

更多请参照Wikipedia的文章 Network Improvement.

I/O buffer size—I/O buffer是用来缓存TCP和它上层协议（就像OpenWire）之间的数据的。默认的I/O buffer的大小是8K，你可以加倍这个大小去获得更好的性能。如例：

tcp://hostA:61617?ioBufferSize=16384

OpenWire protocol：OpenWire协议开放了几个选项进行来调整性能，如表格1.1所示

Parameter Default Description cacheEnabled true Specifies whether to cache commonly repeated values, in order to optimize marshaling. cacheSize 1024 The number of values to cache. Increase this value to improve performance of marshaling. tcpNoDelayEnabled false When true, disable the Nagles algorithm. The Nagles algorithm was devised to avoid sending tiny TCP packets containing only one or two bytes of data; for example, when TCP is used with the Telnet protocol. If you disable the Nagles algorithm, packets can be sent more promptly, but there is a risk that the number of very small packets will increase. tightEncodingEnabled true When true, implement a more compact encoding of basic data types. This results in smaller messages and better network performance, but comes at a cost of more calculation and demands made on CPU time. A trade off is therefore required: you need to determine whether the network or the CPU is the main factor that limits performance.