jmeter中的Latency 与first buffer time

first buffer time

https://blog.csdn.net/weixin_43820813/article/details/123179385

https://admhelp.microfocus.com/lr/en/24.1/help/WebHelp/Content/Analysis/110200_r_GR_Server_Network_Distribution.htm

概括一下:

If the download time for a component is high, you can use this graph to determine whether the problem is server- or network-related.

• Network time is defined as the average amount of time that passes from the moment the first HTTP request is sent until receipt of ACK.

• Server time is defined as the average amount of time that passes from the receipt of ACK of the initial HTTP request (usually GET) until the first buffer is successfully received back from the web server.

客户端和服务端建立连接的ack被回复后【这个是连接建立成功了开始】，到服务端的第一个received back,开始响应了

PS：这样看应该就是TTFB了（https://tangowhisky37.github.io/PracticalPerformanceAnalyst/pages/spe_fundamentals/what_is_time_to_first_buffer/）

问题：ld为什么不直接命名成TTFB而是单独起名字到first buffer呢？

Latency :

https://jmeter.apache.org/usermanual/glossary.html

Latency. JMeter measures the latency from just before sending the request to just after the first response has been received. Thus the time includes all the processing needed to assemble the request as well as assembling the first part of the response, which in general will be longer than one byte. Protocol analysers (such as Wireshark) measure the time when bytes are actually sent/received over the interface. The JMeter time should be closer to that which is experienced by a browser or other application client.

概述：

上面看和TTFB也没有多少区别，唯一jmeter说自己更是浏览器的TTFB而不是wireshark的TTFB这个是把客户端的操作系统内核时间加到这个过程了，

那First Buffer也没说自己是哪个？这样应该就都是应用级别的多了

那Latency基本就是 TTFB只是Jmeter这里没有再区分 成network time和server time了。

[popexizhi: 之前一直以为first buffer 在jmeter没有，看来是自己浅薄了：）]

参考：

https://stackoverflow.com/questions/3957991/jmeter-response-times-ttfb-or-ttlb

https://jmeter.apache.org/usermanual/glossary.html

https://admhelp.microfocus.com/lr/en/24.1/help/WebHelp/Content/Analysis/110200_r_GR_Server_Network_Distribution.htm

https://tangowhisky37.github.io/PracticalPerformanceAnalyst/pages/spe_fundamentals/what_is_time_to_first_buffer/