The NM (and hence, by extension the container) heartbeats to the RM, not the AM. AM gets notified of container status from the RM. The AM starts / stops /releases a container process by communicating to the NM.
Navina On Thu, Jul 30, 2015 at 5:55 PM, Thomas Becker <tobec...@tivo.com> wrote: > Ok, I thought there was some communication from the container to the AM, > it sounds like you're saying it's in the other direction only? Don't > containers heartbeat to the AM? Regardless, even if we can't get a better > address for the AM from YARN, we could at least filter the addresses we get > back from the JVM to exclude loopbacks. > > -Tommy > ________________________________________ > From: Navina Ramesh [nram...@linkedin.com.INVALID] > Sent: Thursday, July 30, 2015 8:40 PM > To: dev@samza.apache.org > Subject: Re: Coordinator URL always 127.0.0.1 > > Hi Tommy, > Yi is right. Container start is coordinated by the AppMaster using an > NMClient. Container host name and port is provided by the RM during > allocation. > In Yarn (at least, afaik), when the node joins a cluster, the NM registers > itself with the RM. So, the NM might still be using > getLocalhost.getAddress(). > > I don't know of any other way to programmatically fetch the machine's > hostname (apart from some hacky shell commands). > > Cheers, > Navina > > On Thu, Jul 30, 2015 at 5:23 PM, Yi Pan <nickpa...@gmail.com> wrote: > > > Hi, Tommy, > > > > Yeah, I agree that the current implementation is not bullet-proof to any > > different networking configuration on the host. As for the AM <-> > container > > communication, if I am not mistaken, it is through the NMClient and the > > node HTTP address is wrapped within the Container object returned from > RM. > > I am not very familiar with that part of source code. Navina may be able > to > > help more here. > > > > -Yi > > > > On Thu, Jul 30, 2015 at 4:27 PM, Thomas Becker <tobec...@tivo.com> > wrote: > > > > > Hi Yi, > > > Thanks a lot for your reply. I don't doubt we can get it to work by > > > mucking with the networking configuration, but to me this feels like a > > > workaround, not a solution. > InetAddress.getLocalHost().getHostAddress() > > is > > > not a reliable way of obtaining an IP that other machines can connect > to. > > > Just today I tested on several Linux distros and it did not work on any > > of > > > them. Can we do something more robust here? How does the container > > > communicate status to the AM? > > > > > > -Tommy > > > > > > ________________________________________ > > > From: Yi Pan [nickpa...@gmail.com] > > > Sent: Thursday, July 30, 2015 6:48 PM > > > To: dev@samza.apache.org > > > Subject: Re: Coordinator URL always 127.0.0.1 > > > > > > Hi, Tommy, > > > > > > I think that it might be a commonly asked question regarding to > multiple > > > IPs on a single host. A common trick w/o changing code is (copied from > > SO: > > > > > > > > > http://stackoverflow.com/questions/2381316/java-inetaddress-getlocalhost-returns-127-0-0-1-how-to-get-real-ip > > > ) > > > > > > {code} > > > > > > 1. > > > > > > Find your host name. Type: hostname. For example, you find your > > hostname > > > is mycomputer.xzy.com > > > 2. > > > > > > Put your host name in your hosts file. /etc/hosts . Such as > > > > > > 10.50.16.136 mycomputer.xzy.com > > > > > > > > > {code} > > > > > > -Yi > > > > > > On Thu, Jul 30, 2015 at 11:35 AM, Tommy Becker <tobec...@tivo.com> > > wrote: > > > > > > > We are testing some jobs on a YARN grid and noticed they are often > not > > > > starting up properly due to being unable to connect to the job > > > coordinator. > > > > After some investigation it seems as if the jobs are always getting a > > > > coordinator URL of http://127.0.0.1:<port> But my understanding is > > that > > > > the coordinator runs only in the AM, so I'd expect these URLs to more > > > often > > > > than not be to some other machine. Looking at the code however, I'm > > not > > > > sure how that would ever happen since the URL for the coordinator > > always > > > > comes from InetAddress.getLocalHost().getHostAddress() in > > > > org.apache.samza.coordinator.server.HttpServer#getUrl > > > > > > > > Am I off base here? Because I don't see how this is ever going to > work > > > in > > > > scenarios where the AM is on a different node than the containers. > > > > > > > > -- > > > > Tommy Becker > > > > Senior Software Engineer > > > > > > > > Digitalsmiths > > > > A TiVo Company > > > > > > > > www.digitalsmiths.com<http://www.digitalsmiths.com> > > > > tobec...@tivo.com<mailto:tobec...@tivo.com> > > > > > > > > ________________________________ > > > > > > > > This email and any attachments may contain confidential and > privileged > > > > material for the sole use of the intended recipient. Any review, > > copying, > > > > or distribution of this email (or any attachments) by others is > > > prohibited. > > > > If you are not the intended recipient, please contact the sender > > > > immediately and permanently delete this email and any attachments. No > > > > employee or agent of TiVo Inc. is authorized to conclude any binding > > > > agreement on behalf of TiVo Inc. by email. Binding agreements with > TiVo > > > > Inc. may only be made by a signed written agreement. > > > > > > > > > > ________________________________ > > > > > > This email and any attachments may contain confidential and privileged > > > material for the sole use of the intended recipient. Any review, > copying, > > > or distribution of this email (or any attachments) by others is > > prohibited. > > > If you are not the intended recipient, please contact the sender > > > immediately and permanently delete this email and any attachments. No > > > employee or agent of TiVo Inc. is authorized to conclude any binding > > > agreement on behalf of TiVo Inc. by email. Binding agreements with TiVo > > > Inc. may only be made by a signed written agreement. > > > > > > > > > -- > Navina R. > > ________________________________ > > This email and any attachments may contain confidential and privileged > material for the sole use of the intended recipient. Any review, copying, > or distribution of this email (or any attachments) by others is prohibited. > If you are not the intended recipient, please contact the sender > immediately and permanently delete this email and any attachments. No > employee or agent of TiVo Inc. is authorized to conclude any binding > agreement on behalf of TiVo Inc. by email. Binding agreements with TiVo > Inc. may only be made by a signed written agreement. > -- Navina R.
