Use the screen command to restart the service in OpenStack

Use the screen command to restart the service in OpenStack

　　In older versions of OpenStack, it is common to use./rejoin-stack.sh to restart all specified services, in the newest master branch, and no rejoin-stack.sh, then restart the service only first. Unstack.sh, and then./stack.sh. Of course not, this is a very waste of time. In fact, we can manage each of the OpenStack services that have been started through the window manager, and after deploying OpenStack with the Devstack installation, multiple OpenStack service processes share a physical terminal's window manager, this screen The session contains multiple screen windows, each of which corresponds to an OpenStack service. We can run the screen-x stack in the Devstack directory to eject this shared screen window, as shown below:

We can see that there are a total of 20 service processes Open here, the last is horizon, then you can use ctrl+a+ ' to enter the Swap window and then enter the number of the corresponding service process (or you can switch directly ctrl+a+n to the next window for the service process, or CTRL + A +p switch to the previous service window), here we enter 6 directly into the n-api* window, which is the OpenStack Nova API service, as follows:

After entering the Nova API window, CTRL + C closes the Nova API service as follows:

When we close the Nova API service, we run the Nova list with an error, and when we press the UP button in the screen window, we can roll back to the command to open the Nova API service,/USR/LOCAL/BIN/GLANCE-API Config-file=/etc/glance/glance-api.conf & Echo $! >/opt/stack/status/stack/g-api.pid; FG | | echo "G-api failed to start" | Tee "/opt/stack/status/stack/g-api.failure",

Press ENTER after you run this command, as follows:

This will open the Nova API service before running the Nova list without error.

The tutorial on restarting the OpenStack service is now complete. Need to restart other services also only need to switch to the corresponding window first CTRL + C, and then press the UP arrow and then enter to run.

Use the screen command to restart the service in OpenStack