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Re: [bgl-discuss] Re: Fw: question about opening sockets from compute nodes (fwd)



Rob,

it's cool!

Do you kwow what system calls are passed to I/O node?

I just did 'string' for ciod.
seems that doSomething() is a system call handler.

$ strings - ciod.440 |grep ciod |grep do

ciod: doOpen: pathname=%s flags=0%06o mode=0%03o rc=%d errnum=%d
ciod: doLink: path=%s link=%s rc=%d errnum=%d
ciod: dosymlink: path=%s link=%s rc=%d errnum=%d
ciod: doUnlink: pathname=%s rc=%d errnum=%d
.....

Thanks,
Kaz


>FYI, discussion with IBM person about running things on IOnodes and 
>connecting to them.
>
>I have successfully created a TCP socket from a compute node and connected 
>to a process on the login node (the sshd in this case).  I'm currently 
>working on hacking netpipe to allow me to test the bandwidth of this 
>connection, which Pete has named the "colon hack" because of the format of 
>the fake filename.  This is how it works:
>
>---
>
>#include <fcntl.h>
>
>int main(int argc, char **argv)
>{
>        int i;
>
>        i = open("tcp://172.30.1.101:22", O_RDWR);
>        printf("open returned %d\n", i);
>        if (i < 0) {
>                perror("open");
>        }
>
>        if (i >= 0) sleep(10);
>
>        return 0;
>}
>
>---
>
><Feb  8 14:54:11> MPIRUN (Info) : Job started successfully
><Feb  8 14:54:11> MPIRUN (Info) : Waiting for job to terminate...
>0: open returned 3
><Feb  8 14:54:41> MPIRUN (Info) : Job 1246 switched to state 
>RM_JOB_TERMINATED ('T')
><Feb  8 14:54:41> MPIRUN (Info) : Job successfully terminated
>
>---
>
>/home/rross> netstat -tan | grep ":22" | grep "172.30.1.101"
>tcp        0      0 172.30.1.101:22         172.30.1.100:1022 ESTABLISHED 
>tcp        0      0 172.30.1.101:22         172.30.1.20:32768 ESTABLISHED 
>/home/rross>
>
>---
>
>I'll report back more when I have the netpipe working...
>
>Rob
>
>---------- Forwarded message ----------
>Date: Tue, 8 Feb 2005 17:47:50 -0500
>From: Christopher Howson <chowson@xxxxxxxxxx>
>To: Rob Ross <rross@xxxxxxxxxxx>
>Subject: Re: Fw: question about opening sockets from compute nodes
>
>Hi,
>
>Do you have anything with powerpc-bgl-linux-gnu?
>Otherwise, I must confess that I don't know what the deployed toolchains 
>look like.
>
>If you are feeling adventurous you might be OK with a standard 
>powerpc-linux-gnu compiler, as the
>user level ISA should be compatible (but don't do floating point).
>
>Regards,
>C. Howson.
>To:     Christopher Howson/Watson/IBM@IBMUS
>cc: 
>Subject:        Re: Fw: question about opening sockets from compute nodes
>
>
>
>Chris,
>
>What's the right toolchain to use to build binaries that will run on an
>IOnode?
>
>Thanks,
>
>Rob
>
>On Tue, 8 Feb 2005, Christopher Howson wrote:
>
>  
>
>>Hi Rob,
>>
>>Yes.
>>If you start the daemon on the IO node at boot, any program on the 
>>    
>>
>compute
>  
>
>>node should be able to connect to
>>it as a client connection to 127.0.0.1.
>>One difficulty would be telling the daemon about job starts and stops so
>>it can clean up any state it has.
>>But that can probably wait for a while (eg. for the time being do it as
>>part of the initial setup can be to clean out the previous state).
>>
>>Regards,
>>C. Howson.
>>
>>
>>To:     Christopher Howson/Watson/IBM@IBMUS
>>cc:     Hao Yu/Watson/IBM@IBMUS
>>Subject:        Re: Fw: question about opening sockets from compute 
>>    
>>
>nodes
>  
>
>>
>>Hi Chris,
>>
>>I can probably do that; we've been discussing that sort of thing here.
>>We've just started to figure out out the boot sequence on the IOnodes
>>works.
>>
>>I guess I would need to use this same open() trick to communicate with a
>>daemon on the IOnode?
>>
>>Thanks,
>>
>>Rob
>>
>>On Tue, 8 Feb 2005, Christopher Howson wrote:
>>
>>    
>>
>>>Can modify your /bgl/dist/etc/rc.local file to start your daemon on
>>>      
>>>
>>system
>>    
>>
>>>boot?
>>>
>>>Regards,
>>>C. Howson.
>>>
>>>PS. They have changed the startup files that get called, but I think
>>>      
>>>
>>that
>>    
>>
>>>rc.local or rc.sysinit should be available somewhere
>>>on the system under /bgl. That is how ciod is started.
>>>
>>>To:     Hao Yu/Watson/IBM@IBMUS
>>>cc:     Christopher Howson/Watson/IBM@IBMUS
>>>Subject:        Re: Fw: question about opening sockets from compute
>>>      
>>>
>>nodes
>>    
>>
>>>
>>>Yes, that's exactly what I'm working on.  I would very much like to be
>>>able to run some sort of user-space helper daemon on the IO node.
>>>
>>>What options are available there?
>>>
>>>Thanks!
>>>
>>>Rob
>>>      
>>>
>>
>>    
>>
>
>
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>  
>

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