[CRIU] criu + threaded program + TCP_REPAIR

[Ruslan Kuprieiev]

On 20.10.2014 04:39, Sowmini Varadhan wrote:
> 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).

Thanks! Will add it to docs.

> 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)?

p.haul doesn't use service, but it uses standalone service worker
by running "criu swrk FD" command.
What does "which criu" show?


Sorry, but I can't answer the rest of the questions.
Pavel?

> 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
>