jmeter - JMeter 中的实现选项是什么？它是如何工作的？

Question

任何人都可以让我了解 JMeter 中的具体实现是什么。如果我在其中选择不同的字段(例如 HC4、HC3.1)，它是如何工作的。另外请告诉我何时使用 Java 以及何时使用 HC4。我们在 HP Load Runner 中是否具有相同的功能。提前致谢。

Answer 1

我相信HTTP Request sampler documentation包含所有答案:

HTTP Request

this has an implementation drop-down box, which selects the HTTP protocol implementation to be used:

Java uses the HTTP implementation provided by the JVM. This has some limitations in comparison with the HttpClient implementations - see below.

HTTPClient3.1 (DEPRECATED SINCE 3.0) uses Apache Commons HttpClient 3.1. This is no longer being developed, and support for this will be dropped in a future JMeter release.

HTTPClient4 uses Apache HttpComponents HttpClient 4.x.

Blank Value does not set implementation on HTTP Samplers, so relies on HTTP Request Defaults if present or on jmeter.httpsampler property defined in jmeter.properties

The Java HTTP implementation has some limitations:

• There is no control over how connections are re-used. When a connection is released by JMeter, it may or may not be re-used by the same thread.

• The API is best suited to single-threaded usage - various settings are defined via system properties, and therefore apply to all connections.

• There is a bug in the handling of HTTPS via a Proxy (the CONNECT is not handled correctly). See Java bugs 6226610 and 6208335.

• It does not support virtual hosts.

• It supports only the following methods: GET, POST, HEAD, OPTIONS, PUT, DELETE and TRACE

• It does not support client based certificate testing with Keystore Config.

因此推荐的选项是使用 HTTPClient4(自 JMeter 3.2 之后您甚至没有 HTTPClient3.1)。

HTTPClient4 是默认 实现，因此您甚至不必为此操心。如果出于某种原因您需要切换到 Java - 您可以使用 HTTP Request Defaults 一次性完成

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LoadRunner 没有此选项，因为它在后台使用 C 语言运行时，而 JMeter 基于 Java。