JMeter性能的一些概念

为减少jmeter对机器性能的消耗，有以下注意事项：

1. 不使用监听器

View Results in Table => OutOfMemory guarantee in GUI Mode
View Results in Tree => OutOfMemory guarantee in GUI Mode
Graph Results => Performance issues
Assertion Results => OutOfMemory guarantee
Comparison Assertion Visualizer
Distribution Graph (alpha) => Performance issues
Graph Results => Performance issues

2. 保持使用最新版本
   新版本JMeter的性能已经得到极大提高

3. 负载测试使用NON-GUI模式

JMeter has 2 modes:
   - GUI mode is for creating the test plan, checking it, debuging it BUT NOT FOR MASSIVE LOAD TEST . AWT Event Thread will disrupt your Load Test.
   - NON-GUI mode is for massive load testing, it is as simple as:

<JMETER_HOME>/bin/jmeter -t <Path to Test Plan> -n -l <path to results>/results.csv

4. 配置合适的JMeter虚拟内存

5. 保存输出结果使用CSV格式
   在属性文件添加如下代码

jmeter.save.saveservice.output_format=csv

jmeter.save.saveservice.data_type=false

jmeter.save.saveservice.label=true

jmeter.save.saveservice.response_code=true

jmeter.save.saveservice.response_data.on_error=false

jmeter.save.saveservice.response_message=false

jmeter.save.saveservice.successful=true

jmeter.save.saveservice.thread_name=true

jmeter.save.saveservice.time=true

jmeter.save.saveservice.subresults=false

jmeter.save.saveservice.assertions=false

jmeter.save.saveservice.latency=true

jmeter.save.saveservice.bytes=true

jmeter.save.saveservice.hostname=true

jmeter.save.saveservice.thread_counts=true

jmeter.save.saveservice.sample_count=true

jmeter.save.saveservice.response_message=false

jmeter.save.saveservice.assertion_results_failure_message=false

jmeter.save.saveservice.timestamp_format=HH:mm:ss

jmeter.save.saveservice.default_delimiter=;

jmeter.save.saveservice.print_field_names=true

6. 有效使用后置处理器和断言

7. 有效使用正则表达式提取器
   最好提取尽量少的数据

8. 尽量不使用XPath提取器

9. 使用Response Assertion or Size assertion
   这两个组件能满足99%的测试需求，避免使用耗资源的组件：

XML Assertion
XML Schema Assertion
XPath Assertion

10. 使用JSR 223 + Groovy编写脚本

11. 执行完测试后再生成报告

12. 分布式（远程）测试
    当使用一台机器达到极限，可以切换为分布式测试或远程测试

13. 若还不能满足
    使用能支持JMeter4的云解决方案

---

来源：
JMeter Performance and Tuning Tips
http://www.ubik-ingenierie.com/blog/jmeter_performance_tuning_tips/