monitor ======= [`monitor`在线教程](https://arthas.aliyun.com/doc/arthas-tutorials.html?language=cn&id=command-monitor) > 方法执行监控 对匹配 `class-pattern`／`method-pattern`／`condition-express`的类、方法的调用进行监控。 `monitor` 命令是一个非实时返回命令. 实时返回命令是输入之后立即返回，而非实时返回的命令，则是不断的等待目标 Java 进程返回信息，直到用户输入 `Ctrl+C` 为止。 服务端是以任务的形式在后台跑任务，植入的代码随着任务的中止而不会被执行，所以任务关闭后，不会对原有性能产生太大影响，而且原则上，任何Arthas命令不会引起原有业务逻辑的改变。 ### 监控的维度说明 |监控项|说明| |---:|:---| |timestamp|时间戳| |class|Java类| |method|方法（构造方法、普通方法）| |total|调用次数| |success|成功次数| |fail|失败次数| |rt|平均RT| |fail-rate|失败率| ### 参数说明 方法拥有一个命名参数 `[c:]`，意思是统计周期（cycle of output），拥有一个整型的参数值 |参数名称|参数说明| |---:|:---| |*class-pattern*|类名表达式匹配| |*method-pattern*|方法名表达式匹配| |*condition-express*|条件表达式| |[E]|开启正则表达式匹配，默认为通配符匹配| |`[c:]`|统计周期，默认值为120秒| |[b]|在**方法调用之前**计算condition-express| ### 使用参考 ```bash $ monitor -c 5 demo.MathGame primeFactors Press Ctrl+C to abort. Affect(class-cnt:1 , method-cnt:1) cost in 94 ms. timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:06:38 demo.MathGame primeFactors 5 1 4 1.15 80.00% timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:06:43 demo.MathGame primeFactors 5 3 2 42.29 40.00% timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:06:48 demo.MathGame primeFactors 5 3 2 67.92 40.00% timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:06:53 demo.MathGame primeFactors 5 2 3 0.25 60.00% timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:06:58 demo.MathGame primeFactors 1 1 0 0.45 0.00% timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2018-12-03 19:07:03 demo.MathGame primeFactors 2 2 0 3182.72 0.00% ``` #### 计算条件表达式过滤统计结果(方法执行完毕之后) ```bash monitor -c 5 demo.MathGame primeFactors "params[0] <= 2" Press Q or Ctrl+C to abort. Affect(class count: 1 , method count: 1) cost in 19 ms, listenerId: 5 timestamp class method total success fail avg-rt(ms) fail-rate ----------------------------------------------------------------------------------------------- 2020-09-02 09:42:36 demo.MathGame primeFactors 5 3 2 0.09 40.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:41 demo.MathGame primeFactors 5 2 3 0.11 60.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:46 demo.MathGame primeFactors 5 1 4 0.06 80.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:51 demo.MathGame primeFactors 5 1 4 0.12 80.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:56 demo.MathGame primeFactors 5 3 2 0.15 40.00% ``` #### 计算条件表达式过滤统计结果(方法执行完毕之前) ```bash monitor -b -c 5 com.test.testes.MathGame primeFactors "params[0] <= 2" Press Q or Ctrl+C to abort. Affect(class count: 1 , method count: 1) cost in 21 ms, listenerId: 4 timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:41:57 demo.MathGame primeFactors 1 0 1 0.10 100.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:02 demo.MathGame primeFactors 3 0 3 0.06 100.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:07 demo.MathGame primeFactors 2 0 2 0.06 100.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:12 demo.MathGame primeFactors 1 0 1 0.05 100.00% timestamp class method total success fail avg-rt(ms) fail-rate ---------------------------------------------------------------------------------------------- 2020-09-02 09:42:17 demo.MathGame primeFactors 2 0 2 0.10 100.00% ```