the suicide operation is only there for testing, for demonstrating that AM restart takes place. It lets us 1. kill an AM on a remote cluster where we don't have the rights to SSH in and kill processes. 2. do it as part of a repeatable sequence, such as here https://github.com/apache/incubator-slider/blob/develop/slider-funtest/src/test/groovy/org/apache/slider/funtest/lifecycle/AMFailuresIT.groovy#L87
so yes, you are right: it's not needed in normal operation. It's only there to help test, verify & demo restart behaviour. On 15 December 2014 at 07:17, 杨浩 <[email protected]> wrote: > I have done an experient, when I kill the am process, all the container > related to this applicationmaster will restart. So the am-suicide method > may not be so useful > > 2014-12-14 13:41 GMT+08:00 杨浩 <[email protected]>: > > > > It's very useful for me the configure is gone. > > As you know , if the am restart , components will not restart. But the am > > process may be killed , like the server which runs am may shutdown, then > > will the component restart? > > > > 2014-12-12 22:08 GMT+08:00 Steve Loughran <[email protected]>: > >> > >> That's something I think we cut out of the slider code a while back, > >> probably before slider 0.50 > >> > >> It was added so that we could work with versions of Hadoop that didn't > >> have > >> working support for the YARN AM restart feature didn't try to use it. > >> > >> Prior to Hadoop 2.4, the fields to enable it weren't in the code the > >> client > >> used to request the feature, or in the data that came back from YARN > when > >> the AM Started. We used reflection to try to load the methods if they > >> weren't there. For extra fun, the method could be in the hadoop JARs on > >> the > >> client, but not on the server, and as we were using the pre-installed > >> hadoop JARs on the server, we could end up setting the option on the > >> client, but not have it do anything. > >> > >> I think the flag was there to tell the tests whether or not the feature > >> was > >> present in the destination cluster, so whether to run tests to kill the > AM > >> and expect it to come back up *retaining the existing containers* —that > >> is, > >> if the AM could be restarted without the running application noticing. > >> > >> Everything works on Hadoop 2.6, so the option is gone, tests do kill the > >> AM > >> and expect it come back (there's a "slider am-suicide" command for > testing > >> this). > >> > >> There's a property "slider.yarn.restart.limit" which sets a limit on how > >> many times slider should ask to restart; if unset you get the YARN limit > >> defined by "yarn.resourcemanager.am.max-retries" (plus some windowing > >> feature which handles intermittent timeouts over a long running > service). > >> Set it to 1 and should say "no restarts" (i.e. one attempt to run slider > >> is > >> made -the first) > >> > >> It's covered in the > >> http://slider.incubator.apache.org/docs/client-configuration.html docs > >> > >> -steve > >> > >> > >> > >> On 12 December 2014 at 11:41, 杨浩 <[email protected]> wrote: > >> > >> > How to configure the configuration? When set false, sometimes it > works, > >> and > >> > sometimes not. > >> > > >> > >> -- > >> CONFIDENTIALITY NOTICE > >> NOTICE: This message is intended for the use of the individual or entity > >> to > >> which it is addressed and may contain information that is confidential, > >> privileged and exempt from disclosure under applicable law. If the > reader > >> of this message is not the intended recipient, you are hereby notified > >> that > >> any printing, copying, dissemination, distribution, disclosure or > >> forwarding of this communication is strictly prohibited. If you have > >> received this communication in error, please contact the sender > >> immediately > >> and delete it from your system. Thank You. > >> > > > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
