由于连接池不够导致创建虚拟机失败问题

CloudOS3.0 + VMware

某局点CloudOS3.0环境，创建云主机时会概率性出现虚拟化集群下的主机无法正常显示的问题。

并且会出现虚拟机创建失败的情况。

通过分析创建失败的虚拟机的nova-compute日志信息，发现虚拟机异常的时候会出现http连接池满的问题。

2018-12-14 13:28:29.990 33553 WARNING requests.packages.urllib3.connectionpool [-] Connection pool is full, discarding connection: 6.7.81.144: Full 

2018-12-14 13:28:30.016 33553 WARNING requests.packages.urllib3.connectionpool [-] Connection pool is full, discarding connection: 6.7.81.144: Full 

2018-12-14 13:28:30.021 33553 WARNING requests.packages.urllib3.connectionpool [-] Connection pool is full, discarding connection: 6.7.81.144: Full 

2018-12-14 13:28:30.025 33553 WARNING requests.packages.urllib3.connectionpool [-] Connection pool is full, discarding connection: 6.7.81.144: Full 

2018-12-14 13:28:30.030 33553 WARNING requests.packages.urllib3.connectionpool [-] Connection pool is full, discarding connection: 6.7.81.144: Full

因此，确认是http池不够了，导致虚拟机创建失败，以及无法显示主机等信息。

经确认compute容器下默认的连接池参数“DEFAULT_POOLSIZE”是10，可以修改为100。该参数需要固化。

配置文件的路径为：/usr/lib/python2.7/site-packages/requests/adapters.py   

修改后需要重启 openstack-nova-compute服务。  

[root@computecasrc requests]# systemctl status openstack-nova-compute.service ● openstack-nova-compute.service - OpenStack Nova Compute Server Loaded: loaded (/usr/lib/systemd/system/openstack-nova-compute.service; enabled; vendor preset: disabled) Active: active (running) since Thu 2018-12-20 12:44:59 CST; 22s ago Main PID: 9993 (nova-compute) CGroup: /docker/b8d2da607e77d54edaae8f56398f545d2ea02fd7a98a86194a0284e095a7ed04/system.slice/openstack-nova-compute.service └─9993 /usr/bin/python2 /usr/bin/nova-compute Dec 20 12:44:49 computecasrc systemd[1]: Starting OpenStack Nova Compute Server... Dec 20 12:44:57 computecasrc nova-compute[9993]: Option "verbose" from group "DEFAULT" is deprecated for removal. Its value may be silently ignored in the future. Dec 20 12:44:57 computecasrc nova-compute[9993]: Option "notification_driver" from group "DEFAULT" is deprecated. Use option "driver" from group "oslo_messaging_notifications". Dec 20 12:44:58 computecasrc nova-compute[9993]: /usr/lib/python2.7/site-packages/pkg_resources/__init__.py:187: RuntimeWarning: You have iterated over the result of pkg_resources.parse_version. This is a legacy behavior which is inconsistent with the new version class... Dec 20 12:44:58 computecasrc nova-compute[9993]: stacklevel=1, Dec 20 12:44:59 computecasrc systemd[1]: Started OpenStack Nova Compute Server. Hint: Some lines were ellipsized, use -l to show in full. [root@computecasrc requests]#