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<p>Hi,</p>
<p>Finally, the issue solved. It is caused by the low number of
connections set to memcached servers: 1024. I noticed too many
files open and too many sockets errors in my logs. Changing the
memcached max allowed connections to 2048 or higher solved my
problem.</p>
<p>You can check your memcached server: echo stats|nc localhost
11211|grep listen_disabled . If you have listen_disabled > 1
you need to increase the max connections for you memcached server.</p>
<p>For the OSA you need to set this parameter: <code>memcached_connections:
4096</code></p>
<pre class="moz-signature" cols="72">Regards,
Robert Varjasi
consultant@Component Soft Ltd.
Tel: +36/30-259-9221</pre>
<div class="moz-cite-prefix">On 10/12/2018 04:35 PM, Robert Varjasi
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:915bf691-d741-dd9c-7143-050088b5700b@componentsoft.io">
<pre wrap="">Hi,
I found that my controller nodes were a bit overloaded with 16 uwsgi
nova-api-os compute processes. I reduced the nova-api-os uwsgi processes
to 10 and timeout and slowdowns were eliminated. My cloud went stable
and the response times went lower. I have 20 vcpus on a Xeon(R) CPU
E5-2630 v4 @ 2.20GHz.
For the openstack-ansible I need to change this variable from 16 to 10:
nova_wsgi_processes_max: 10. Seems I need to set it to an equal number
of my cpu cores.
Regards,
Robert Varjasi
consultant@Component Soft Ltd.
Tel: +36/30-259-9221
On 10/08/2018 06:33 PM, Robert Varjasi wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
After a few tempest run I noticed slowdowns in the nova-api-os-compute
uwsgi processes. I check the processes with py-spy and found that a lot
of process blocked on read(). Here is my py-spy output from one of my
nova-api-os-compute uwsgi process: <a class="moz-txt-link-freetext" href="http://paste.openstack.org/show/731677/">http://paste.openstack.org/show/731677/</a>
And the stack trace:
thread_id = Thread-2 filename = /usr/lib/python2.7/threading.py lineno =
774 function = __bootstrap line = self.__bootstrap_inner()
thread_id = Thread-2 filename = /usr/lib/python2.7/threading.py lineno =
801 function = __bootstrap_inner line = self.run()
thread_id = Thread-2 filename = /usr/lib/python2.7/threading.py lineno =
754 function = run line = self.__target(*self.__args, **self.__kwargs)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py
lineno = 382 function = poll line =
self.conn.consume(timeout=current_timeout)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/oslo_messaging/_drivers/impl_rabbit.py
lineno = 1083 function = consume line = error_callback=_error_callback)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/oslo_messaging/_drivers/impl_rabbit.py
lineno = 807 function = ensure line = ret, channel = autoretry_method()
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/kombu/connection.py
lineno = 494 function = _ensured line = return fun(*args, **kwargs)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/kombu/connection.py
lineno = 570 function = __call__ line = return fun(*args,
channel=channels[0], **kwargs), channels[0]
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/oslo_messaging/_drivers/impl_rabbit.py
lineno = 796 function = execute_method line = method()
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/oslo_messaging/_drivers/impl_rabbit.py
lineno = 1068 function = _consume line =
self.connection.drain_events(timeout=poll_timeout)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/kombu/connection.py
lineno = 301 function = drain_events line = return
self.transport.drain_events(self.connection, **kwargs)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/kombu/transport/pyamqp.py
lineno = 103 function = drain_events line = return
connection.drain_events(**kwargs)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/amqp/connection.py
lineno = 471 function = drain_events line = while not
self.blocking_read(timeout):
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/amqp/connection.py
lineno = 476 function = blocking_read line = frame =
self.transport.read_frame()
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/amqp/transport.py
lineno = 226 function = read_frame line = frame_header = read(7, True)
thread_id = Thread-2 filename =
/openstack/venvs/nova-17.0.4/lib/python2.7/site-packages/amqp/transport.py
lineno = 346 function = _read line = s = recv(n - len(rbuf)) # see note
above
thread_id = Thread-2 filename = /usr/lib/python2.7/ssl.py lineno = 643
function = read line = v = self._sslobj.read(len)
I am using nova 17.0.4.dev1, amqp (2.2.2), oslo.messaging (5.35.0),
kombu (4.1.0). I have 3 controller nodes. The openstack deployed by OSA
17.0.4.
I can reproduce the read() block if I click on "Log" in Horizon to see
the console outputs from one of my VM or run a tempest test:
tempest.api.compute.admin.test_hypervisor.HypervisorAdminTestJSON.test_get_hypervisor_uptime.
The nova-api response time increasing when more and more nova-api
processes get blocked at this read. Is it a normal behavior?
---
Regards,
Robert Varjasi
consultant@Component Soft Ltd.
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
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