在 YARN 中，托管和非托管应用程序管理器有什么区别答案

【问题标题】：In YARN what is the difference between a managed and an unmanaged Application Manager在 YARN 中，托管和非托管应用程序管理器有什么区别
【发布时间】：2014-02-19 17:38:13
【问题描述】：

我正在试验 YARN 2.2 中的分布式 Shell 示例，希望有人能澄清托管和非托管应用程序管理器之间的区别是什么？

例如以下行出现在客户端代码中

// unmanaged AM
appContext.setUnmanagedAM(true);

但我找不到解释这一行对执行行为的影响的文档。

非常感谢。

【问题讨论】：

标签： hadoop-yarn

【解决方案1】：

setUnmanagedAM(true) 用于调试目的，即它以本地模式运行应用程序管理器并且不将其提交到集群，因此更容易进入代码和调试。您可以在 yarn 附带的 hadoop-yarn-applications-unmanaged-am-launcher.jar 中看到它的使用情况

【讨论】：

谢谢，你能给我举个简单的例子吗？
在 YARN 应用的正常运行中，AM 在集群上运行。

【解决方案2】：

检查相应的 JIRA 票证：JIRA-420 和 JIRA-419 (client side)

Currently, the RM itself manages the AM by allocating a container for it and negotiating the launch on the NodeManager and manages the AM lifecycle. Thereafter, the AM negotiates resources with the RM and launches tasks to do the real work.
It would be a useful improvement to enhance this model by allowing the AM to be launched independently by the client without requiring the RM. These AM's would be launched on a gateway machine that can talk to the cluster. This would open up new use cases such as the following
1) Easy debugging of AM, specially during initial development. Having the AM launched on an arbitrary cluster node makes it hard to looks at logs or attach a debugger to the AM. If it can be launched locally then these tasks would be easier.
2) Running AM's that need special privileges that may not be available on machines managed by the NodeManager

关于非托管 AM 的更多实施细节的博文：click-me

Impala 如何借助非托管应用程序管理其资源的示例：Llama

【讨论】：