NGINX is delivered by its creators in two distinct branches: stable and mainline.
We support both. The default is stable. Both branches are actually stable, but represent different NGINX feature sets and compatibility levels.
Which one is best for you? It depends.
The stable NGINX branch
When you simply set up GetPageSpeed repository on your system, you are able to install stable NGINX packages, by default.
The stable branch has less moving parts, and NGINX itself is rarely updated on it. However, since it is not receiving frequent feature updates, it means there is less chances new bugs are introduced to it.
The mainline NGINX branch
The mainline branch has frequent updates, and so you can expect more package updates, as the newer versions are released.
While it does fix any issues found in the stable branch, it has the potential of bringing more issues via new features' code.
The mainline NGINX has a higher chance of bringing backwards incompatible changes.
Stick to the stable branch, unless you are very eager to try out a new feature, fix a severe security bug, and/or have the time to deal with potential (although rare) backwards incompatible changes.
Still want to go with mainline?
You can install mainline NGINX module packages easily by enabling the
sudo yum -y --disablerepo getpagespeed-extras install yum-utils sudo yum-config-manager --enable getpagespeed-extras-mainline
yum upgrade to ensure all the NGINX modules currently installed are switched to mainline.
Then install additional modules as usual, e.g.:
sudo yum -y install nginx-module-security
Changed your mind and want to go with stable?
For reasons mentioned above, you may want to downgrade to the stable branch:
sudo yum-config-manager --disable getpagespeed-extras-mainline sudo yum -y downgrade "nginx*"