ps启动时出core

日志如下：

Segmentation fault (core dumped)

cmd: /usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/utils/../../bin/ps -bc "False" -sp "zfs://172.21.9.152:12181" -si "1" -r "server"

Traceback (most recent call last):

  File "../../testMark.py", line 18, in 

    import xdl

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/__init__.py", line 16, in 

    from xdl.python.init import *

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/__init__.py", line 16, in 

    from xdl.python.init import *

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/init.py", line 42, in 

    from xdl.python.training.train_session import TrainSession, LoggerHook, SyncRunHook, SemiSyncRunHook, BarrierHook

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/train_session.py", line 21, in 

    from xdl.python.training.env import current_env, is_local_mode

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/env.py", line 228, in 

    _ENV = init_env()

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/env.py", line 226, in init_env

    return DistributedEnv()

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/env.py", line 148, in __init__

    self._start()

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/env.py", line 54, in _start

    self._ps_do()

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/training/env.py", line 157, in _ps_do

    bind_cores = self._bind_core)

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/utils/ps_utils.py", line 78, in run_ps_server

    bc=bind_cores)

  File "/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/utils/ps_utils.py", line 67, in run_ps_cmd

    raise ValueError("Run cmd Error, cmd=[%s] exit_code=[%s]" % (cmd, ret))

ValueError: Run cmd Error, cmd=[/usr/local/lib/python2.7/dist-packages/xdl-1.0-py2.7.egg/xdl/python/utils/../../bin/ps -bc "False" -sp "zfs://172.21.9.152:12181" -si "1" -r

 "server"] exit_code=[35584]

core堆栈：

(gdb) bt

#0  0x0000000000e1d812 in ps::network::SessionContext::SetProcessorId (this=0x0, id=2) at /xdl/xdl/third_party/seastar/service/session_context.hh:37

#1  0x0000000000e204ac in ps::network::ClientNetworkContext::SetResponseProcessorIdOfServer (this=0x7f010ec59948, serverId=0, id=2)

    at /xdl/xdl/third_party/seastar/service/client_network_context.hh:227

#2  0x0000000000e6e3b1 in ps::service::seastar::SeastarServerClientLib::Connect (this=0x7f010ec59800, server_id=0, addr="172.17.0.2:43207", async=false,

    connect_in_seastar=false) at /xdl/xdl/ps-plus/ps-plus/service/seastar/lib/seastar_server_client_lib.cc:155

#3  0x0000000000ca1e8c in ps::server::ServerService::RegisterServer (this=0x7ffd3de5a8c0) at /xdl/xdl/ps-plus/ps-plus/server/server_service.cc:360

#4  0x0000000000c9ebe9 in ps::server::ServerService::::operator()(void) const (__closure=0x7f0050b64458) at /xdl/xdl/ps-plus/ps-plus/server/server_service.cc:158

#5  0x0000000000ca6f1e in std::_Bind_simple()>::_M_invoke<>(std::_Index_tuple<>) (this=0x7f0050b64458)

    at /usr/include/c++/5/functional:1531

#6  0x0000000000ca6e74 in std::_Bind_simple()>::operator()(void) (this=0x7f0050b64458) at /usr/include/c++/5/functional:1520

#7  0x0000000000ca6e04 in std::thread::_Impl()> >::_M_run(void) (this=0x7f0050b64440)

    at /usr/include/c++/5/thread:115

#8  0x00007f0113e3ac80 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6

#9  0x00007f01116756ba in start_thread (arg=0x7eff893ff700) at pthread_create.c:333

#10 0x00007f0110e8041d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

(gdb) f 1

#1  0x0000000000e204ac in ps::network::ClientNetworkContext::SetResponseProcessorIdOfServer (this=0x7f010ec59948, serverId=0, id=2)

    at /xdl/xdl/third_party/seastar/service/client_network_context.hh:227

227             mSessionsContext[serverId]->SetProcessorId(id);

Start with ps-plus/ps-plus/service/seastar/lib/seastar_server_client_lib.cc:155 and third_party/seastar/service/client_network_context.hh:227, then inspect the gdb backtrace through ServerService::RegisterServer. Reproduce the reported ps command and determine why mSessionsContext[serverId] is null; done means ps starts without the segmentation fault and the failure is covered by an appropriate regression check.

Written by the indexing model from the issue text.