diff --git a/site/src/site/sphinx/async.md b/site/src/site/sphinx/async.md index 92e971c7..90e827da 100644 --- a/site/src/site/sphinx/async.md +++ b/site/src/site/sphinx/async.md @@ -36,8 +36,8 @@ $ jobs * ‘ctrl + d’:按照linux语义应当是退出终端,目前arthas中是空实现,不处理 ## 4. fg、bg命令,将命令转到前台、后台继续执行 -* 任务在后台执行或者暂停状态(‘ctrl + z’暂停任务)时,执行fg 将可以把对应的任务转到前台继续执行。在前台执行时,无法在console中执行其他命令 -* 当任务处于暂停状态时(‘ctrl + z’暂停任务),执行bg 将可以把对应的任务在后台继续执行 +* 任务在后台执行或者暂停状态(`ctrl + z`暂停任务)时,执行`fg `将可以把对应的任务转到前台继续执行。在前台执行时,无法在console中执行其他命令 +* 当任务处于暂停状态时(`ctrl + z`暂停任务),执行`bg `将可以把对应的任务在后台继续执行 * 非当前session创建的job,只能由当前session fg到前台执行 ## 5. 任务输出重定向 @@ -48,7 +48,7 @@ $ trace Test t >> test.out & ``` 这时trace命令会在后台执行,并且把结果输出到~/logs/arthas-cache/test.out。可继续执行其他命令。并可查看文件中的命令执行结果。 -当远程调用时,可能无法确定机器文件路径,arthas同时支持了自动重定向到缓存路径。使用方法如下: +当连接到远程的arthas server时,可能无法查看远程机器的文件,arthas同时支持了自动重定向到本地缓存路径。使用方法如下: ```sh $ trace Test t >> & job id : 2 diff --git a/site/src/site/sphinx/en/async.md b/site/src/site/sphinx/en/async.md new file mode 100644 index 00000000..2f53e041 --- /dev/null +++ b/site/src/site/sphinx/en/async.md @@ -0,0 +1,83 @@ +Arthas Async Jobs +=== + +Asynchronous jobs in arthas, using commands related to linux jobs.[linux man jobs](http://man7.org/linux/man-pages/man1/jobs.1p.html)。 + + +## 1. Use & to run the command in the background + +For example, execute the trace command in the background: + +```sh +trace Test t & +``` + +## 2. List background jobs + +If you want to list all background jobs, you can execute the `jobs` command and the results are as follows: + + +```sh +$ jobs +[10]* + Stopped watch com.taobao.container.Test test "params[0].{? #this.name == null }" -x 2 + execution count : 19 + start time : Fri Sep 22 09:59:55 CST 2017 + timeout date : Sat Sep 23 09:59:55 CST 2017 + session : 3648e874-5e69-473f-9eed-7f89660b079b (current) +``` + +You can see that there is currently a background job executing. + +* job id is 10, `*` indicates that this job is created by the current session. +* status is `Stopped` +* execution count is the number of executions, which have been executed 19 times since the start. +* timeout date: After this time, the job will automatically timeout and exit. + +## 3. Suspend and Cannel job + +When the job is executing in the foreground, such as directly calling the command `trace Test t` or calling the background job command `trace Test t &`, the job is transferred to the foreground through the `fg` command. At this point, the console cannot continue to execute the command, but can receive and process the following keyboard events: + +* ‘ctrl + z’: Suspend the job, the job status will change to `Stopped`, and the job can be restarted by `bg ` or `fg ` +* ‘ctrl + c’: Stop the job +* ‘ctrl + d’: According to linux semantics should be the exit terminal, currently arthas ignore this input. + + + +## 4. fg/bg, Bring a background job to the foreground/Restart a stopped background job + +* When the job is executed in the background or suspended (`ctrl + z` to suspend job), executing `fg ` will transfer the corresponding job to the foreground to continue execution. +* When the job is suspended (`ctrl + z` to suspend job), executing `bg ` will continue the corresponding job in the background. +* A job created by a non-current session can only be executed by the current session fg to the foreground. + +## 5. Redirect the job output + +The job output can be redirect to the specified file by `>` or `>>`, and can be used together with `&` to implement the asynchronous job of the arthas command. such as: + +```sh +$ trace Test t >> test.out & +``` + +The trace command will be executed in the background and the output will be redirect to `~/logs/arthas-cache/test.out`. You can continue to execute other commands in the console. + + +When connecting to a remote arthas server, you may not be able to view the files of the remote machine. Arthas also supports automatic redirection to the local cache file. Examples are as follows: + +```sh +$ trace Test t >> & +job id : 2 +cache location : /Users/gehui/logs/arthas-cache/28198/2 +``` + +You can see that does not specify the redirect file after `>>`, arthas will automatically redirect the job output to the `~/logs/arthas-cache`. + +In the above example, pid is `28198` and job id is `2`. + +## 6. Stop job + +If you want to stop background job, just `kill `. + +## 7. Others + +* Support up to 8 commands at the same time redirect the output to the log file. +* Do not open too many background asynchronous commands at the same time to avoid affecting the performance of the target JVM. \ No newline at end of file