[CRIU] criu + threaded program + TCP_REPAIR

[Sowmini Varadhan]

On (10/19/14 20:03), Ruslan Kuprieiev wrote:
> >    python-protobuf[.socketrpc]
> 
> You don't need python-protobuf.socketrpc. rpc_pb2.py and stats_pb2.py
> are to be generated by running "make" in p.haul root directory.
> Just sent the patch to explain how to get p.haul ready.

Thanks!

One more piece of useful info for the HOWTO page - in 
addition to the protobuf packages listed in the criu page,
and python-protobuf, you also need protobuf-compiler (for protoc).

But even after all that, I run into this:
root at vm:~/src/p.haul# ./p.haul lxc 31692 192.168.122.54
Connecting to target host
Setting up local
`- Passing (ctl:5, data:4) pair to CRIU
Traceback (most recent call last):
  File "./p.haul", line 37, in <module>
    worker = ph_iters.phaul_iter_worker(ph_type, dst)
  File "/home/sowmini/src/p.haul/p_haul_iters.py", line 35, in __init__
    self.criu = criu_api.criu_conn(self.data_sk)
  File "/home/sowmini/src/p.haul/criu_api.py", line 40, in __init__
    self._swrk = subprocess.Popen([criu_binary, "swrk", "%d" % css[0].fileno()])
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory


Here the 31692 is pid of the init for the lxc, and the IP address
is the address of the target VM.  Looks like we did connect to the
target, but something went wrong when talking to the local criu service,
The log file for the criu service doesnt show anything remarkable
root at vm:~/src/criu# cat /tmp/criu.log
  (00.000515) The service socket is bound to /var/run/criu_service.socket
  (00.000986) Waiting for connection...
So am I missing something obvious here (before I try to debug this further)?

and, back to the "do this from First Principles" question..  If I do  this;

> >In any case, I also tried to just spawn my process from something like
> >ns_child_exec.c [http://lwn.net/Articles/533492/].
> >
> >So if I do this:
> >
> >   # ns_child_exec -v -p bash
> >   pidns# iperf -s &
And try to do a dump using the pid of ns_child_exec, I get:

> >Error (namespaces.c:196): Can't dump nested pid namespace for 15022
> >Error (namespaces.c:392): Can't make pidns id

If I do this with the pid of bash, I get an error about 

> > Error (cr-dump.c:1581): A session leader of 27223(1) is outside of its pid namespace
> > Error (cr-dump.c:1949): Dumping FAILED.

If I do this with the pid of iperf, I get 

> > Error (proc_parse.c:357): Unsupported mapping found 00000000f7786000-00000000f7788000
> > Error (bfd.c:118): Error flushing image

Which pid should I use, if I want to directly use criu itself?

--Sowmini