Jeff Zhang 8fa534343b [ZEPPELIN-4066]. Introduce ProcessLauncher to encapsulate process launch ... ### What is this PR for? There're several places in zeppelin to launch processes, such as interpreter process launch, python process launch. Sometimes it is very hard to diagnose if the process is failed to launch or some error happens during its lifecycle. This PR introduce ProcessLauncher to encapsulate process launch. ProcessLauncher will do most of the process launching stuff but also allow for customization. E.g. how to check the process is started properly. And when error happens, ProcessLauncher will capture the necessary error output for further diagnose. ### What type of PR is it? [ Improvement | Refactoring] ### Todos * [ ] - Task ### What is the Jira issue? * https://jira.apache.org/jira/browse/ZEPPELIN-4066 ### How should this be tested? * Ci pass ### Screenshots (if appropriate) ### Questions: * Does the licenses files need update? No * Is there breaking changes for older versions? No * Does this needs documentation? No Author: Jeff Zhang <zjffdu@apache.org> Closes #3346 from zjffdu/ZEPPELIN-4066 and squashes the following commits: b847d6d86 [Jeff Zhang] Add state COMPLETED & also add transition method for more detail logging 97049bd55 [Jeff Zhang] [ZEPPELIN-4066]. Introduce ProcessLauncher to encapsulate process launch		2019-04-18 17:42:42 +08:00
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main	[ZEPPELIN-4066]. Introduce ProcessLauncher to encapsulate process launch	2019-04-18 17:42:42 +08:00
test	[ZEPPELIN-4066]. Introduce ProcessLauncher to encapsulate process launch	2019-04-18 17:42:42 +08:00