Merge "Add a doc for Zun integration with OSProfiler"

doc/source/osprofiler.rst

@@ -0,0 +1,77 @@
+..
+      Licensed under the Apache License, Version 2.0 (the "License"); you may
+      not use this file except in compliance with the License. You may obtain
+      a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+      See the License for the specific language governing permissions and
+      limitations under the License.
+
+======================
+ Use OSProfiler in Zun
+======================
+
+This is the demo for Zun integrating with osprofiler. `Zun
+<https://wiki.openstack.org/wiki/Zun>`_ is a OpenStack container
+management services, while `OSProfiler
+<https://docs.openstack.org/developer/osprofiler/>`_ provides
+a tiny but powerful library that is used by most OpenStack projects and
+their python clients.
+
+Install Redis database
+----------------------
+
+After osprofiler 1.4.0, user can choose mongodb or redis as the backend storage
+option without using ceilometer. Here just use Redis as an example, user
+can choose mongodb, elasticsearch, and `etc
+<https://github.com/openstack/osprofiler/tree/master/osprofiler/drivers>`_.
+Install Redis as the `centralized collector
+<https://github.com/openstack/osprofiler/blob/master/doc/source/collectors.rst>`_
+Redis in container is easy to launch, `choose Redis Docker
+<https://hub.docker.com/_/redis/>`_ and run::
+
+        docker run --name some-redis -p 6379:6379 -d redis
+
+Now there is a redis database which has an expose port to access. OSProfiler
+will send data to this key-value database.
+
+Change the configure file
+-------------------------
+
+Change the /etc/zun/zun.conf, add the following lines, change the <ip-address>
+to the real IP::
+
+        [profiler]
+        enabled = True
+        trace_sqlalchemy = True
+        hmac_keys = SECRET_KEY
+        connection_string = redis://<ip-address>:6379/
+
+Then restart zun-api and zun-compute (Attention, the newest version of
+Zun has move zun-api service to apache2 server. You can't restart the
+service just in screen. Use "systemctl restart apache2" will work)
+
+Use below commands to get the trace information::
+
+        $ zun --profile SECRET_KEY list
+        # you will get a <TRACE-ID> for trace
+        $ osprofiler trace show <TRACE-ID> --connection-string=redis://<ip-address>:6379 --html
+
+
+Troubleshooting
+---------------
+
+How to check whether the integration is fine:
+Stop the Redis container, then run the command::
+
+    zun --profile SECRET_KEY list
+
+In the zun-api log, will see "ConnectionError: Error 111 connecting to
+<ip-address>:6379. ECONNREFUSED." That means that osprofiler will write
+the trace data to redis, but can't connect it. So the integration is fine.
+/etc/zun/api-paste.ini file changed (change the pipeline) need to re-deploy
+the devstack.