[ovirt-devel] Re: "Too many open files" in vdsm.log after 380 migrations

On Tue, Feb 9, 2021 at 8:55 AM Yedidyah Bar David <didi(a)redhat.com&gt; wrote: > > On Mon, Feb 8, 2021 at 7:05 PM Nir Soffer <nsoffer(a)redhat.com&gt; wrote: > > > > On Mon, Feb 8, 2021 at 6:47 PM Asaf Rachmani <arachman(a)redhat.com&gt; wrote: > > > > > > > > > I didn't check it yet, but maybe this customer bug is related to this discussion: > > > https://bugzilla.redhat.com/show_bug.cgi?id=1666553 > > > > This bug is about the broker opening too many connections > > to vdsm: > > https://bugzilla.redhat.com/show_bug.cgi?id=1666553#c1 > > > > If the broker keeps 1000's of connections open it it likey that > > vdsm will run out of fds. > > > > > From vdsm.log: > > > 2019-01-15 13:41:11,162+0000 INFO (periodic/2) [vdsm.api] FINISH multipath_health return={} from=internal, task_id=97c359aa-002e-46d8-9fc5-2477db0909b4 (api:52) > > > 2019-01-15 13:41:12,210+0000 WARN (vdsm.Scheduler) [Executor] Worker blocked: <Worker name=jsonrpc/0 running <Task <JsonRpcTask {'params': {}, 'jsonrpc': '2.0', 'method': u'Host.getCapabilities', 'id': u'74b9dc62-22b2-4698-9d84-6a71c4f29763'} at 0x7f71dc31b0d0> timeout=60, duration=60 at 0x7f71dc31b110> task#=33 at 0x7f722003c890>, traceback: > > > File: "/usr/lib64/python2.7/threading.py", line 785, in __bootstrap > > > self.__bootstrap_inner() > > > File: "/usr/lib64/python2.7/threading.py", line 812, in __bootstrap_inner > > > self.run() > > > File: "/usr/lib64/python2.7/threading.py", line 765, in run > > > self.__target(*self.__args, **self.__kwargs) > > > File: "/usr/lib/python2.7/site-packages/vdsm/common/concurrent.py", line 194, in run > > > ret = func(*args, **kwargs) > > > File: "/usr/lib/python2.7/site-packages/vdsm/executor.py", line 301, in _run > > > self._execute_task() > > > File: "/usr/lib/python2.7/site-packages/vdsm/executor.py", line 315, in _execute_task > > > task() > > > File: "/usr/lib/python2.7/site-packages/vdsm/executor.py", line 391, in __call__ > > > self._callable() > > > File: "/usr/lib/python2.7/site-packages/yajsonrpc/__init__.py", line 523, in __call__ > > > self._handler(self._ctx, self._req) > > > File: "/usr/lib/python2.7/site-packages/yajsonrpc/__init__.py", line 566, in _serveRequest > > > response = self._handle_request(req, ctx) > > > File: "/usr/lib/python2.7/site-packages/yajsonrpc/__init__.py", line 606, in _handle_request > > > res = method(**params) > > > File: "/usr/lib/python2.7/site-packages/vdsm/rpc/Bridge.py", line 197, in _dynamicMethod > > > result = fn(*methodArgs) > > > File: "<string>", line 2, in getCapabilities > > > File: "/usr/lib/python2.7/site-packages/vdsm/common/api.py", line 48, in method > > > ret = func(*args, **kwargs) > > > File: "/usr/lib/python2.7/site-packages/vdsm/API.py", line 1337, in getCapabilities > > > c = caps.get() > > > File: "/usr/lib/python2.7/site-packages/vdsm/host/caps.py", line 168, in get > > > net_caps = supervdsm.getProxy().network_caps() > > > File: "/usr/lib/python2.7/site-packages/vdsm/common/supervdsm.py", line 55, in __call__ > > > return callMethod() > > > File: "/usr/lib/python2.7/site-packages/vdsm/common/supervdsm.py", line 53, in <lambda> > > > **kwargs) > > > File: "<string>", line 2, in network_caps > > > File: "/usr/lib64/python2.7/multiprocessing/b", line 759, in _callmethod > > > kind, result = conn.recv() (executor:363) > > > > > > > > > > > > > > > On Mon, Feb 8, 2021 at 5:52 PM Nir Soffer <nsoffer(a)redhat.com&gt; wrote: > > >> > > >> On Mon, Feb 8, 2021 at 1:22 PM Yedidyah Bar David <didi(a)redhat.com&gt; wrote: > > >> > > > >> > On Mon, Feb 8, 2021 at 9:05 AM Yedidyah Bar David <didi(a)redhat.com&gt; wrote: > > >> > > > > >> > > Hi all, > > >> > > > > >> > > I ran a loop of [1] (from [2]). The loop succeeded for ~ 380 > > >> > > iterations, then failed with 'Too many open files'. First failure was: > > >> > > > > >> > > 2021-02-08 02:21:15,702+0100 ERROR (jsonrpc/4) [storage.HSM] Could not > > >> > > connect to storageServer (hsm:2446) > > >> > > Traceback (most recent call last): > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/storage/hsm.py", line > > >> > > 2443, in connectStorageServer > > >> > > conObj.connect() > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/storage/storageServer.py", > > >> > > line 449, in connect > > >> > > return self._mountCon.connect() > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/storage/storageServer.py", > > >> > > line 171, in connect > > >> > > self._mount.mount(self.options, self._vfsType, cgroup=self.CGROUP) > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/storage/mount.py", line > > >> > > 210, in mount > > >> > > cgroup=cgroup) > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/common/supervdsm.py", > > >> > > line 56, in __call__ > > >> > > return callMethod() > > >> > > File "/usr/lib/python3.6/site-packages/vdsm/common/supervdsm.py", > > >> > > line 54, in <lambda> > > >> > > **kwargs) > > >> > > File "<string>", line 2, in mount > > >> > > File "/usr/lib64/python3.6/multiprocessing/managers.py", line 772, > > >> > > in _callmethod > > >> > > raise convert_to_error(kind, result) > > >> > > OSError: [Errno 24] Too many open files > > >> > > >> Maybe we have a fd leak in supervdsmd? > > >> > > >> We know that there a small memory leak in multiprocessing, but not > > >> about any fd leak. > > >> > > >> > > But obviously, once it did, it continued failing for this reason on > > >> > > many later operations. > > >> > > >> Smells like fd leak. > > >> > > >> > > Is this considered a bug? > > >> > > >> Generally yes, but the question is if this happens during > > >> real world scenarios. > > >> > > >> > Do we actively try to prevent such cases? > > >> > > >> No, we don't have any code monitoring number of open fds > > >> in runtime, or tests checking this in system tests. > > >> > > >> We do have health monitor in vdsm: > > >> https://github.com/oVirt/vdsm/blob/master/lib/vdsm/health.py > > >> > > >> It can be useful to log monitor also the number of fds (.e.g ls -lh > > >> /proc/pid/fd). > > >> > > >> We don't have any monitor in supervdsm, it can be useful to add > > >> one. supervdsm is relatively simple, but the problem is it runs > > >> possibly complex code from vdsm, so "safe" changes in vdsm can > > >> cause trouble when the code is run by supervdsm. > > >> > > >> > So should I open one and attach logs? Or it can be considered a "corner > > >> > > case"? > > >> > > >> Yes, please open a bug, and include the info you have. > > Done, https://bugzilla.redhat.com/show_bug.cgi?id=1926589 . > > > >> > > >> Please include output of "ls -lh /proc/pid/fd" for both vdsm > > >> and supervdsm when you reproduce the issue, or during the > > >> long test if you cannot reproduce. > > >> > > >> > > Using vdsm-4.40.50.3-37.git7883b3b43.el8.x86_64 from > > >> > > ost-images-el8-he-installed-1-202102021144.x86_64 . > > >> > > > > >> > > I can also let access to the machine(s) if needed, for now. > > >> > > > >> > Sorry, now cleaned this env. Can try to reproduce if there is interest. > > >> > > >> It will help you can reproduce. > > Trying now. It didn't fail yet (finished 45 iterations), but it already seems like supervdsm is leaking. When I started, it had 30+ open files (32 on host-0, 35 on host-1), now it has 160+ (169, 166). Not sure how to see what's leaking. Almost all of them are pipes. I'll run strace on it for some time, hopefully this can help.