Migrate from mod_pagespeed 1.15

The move from a 1.15 install is a package upgrade in place. mod_pagespeed 2.1 continues the 1.15 module lineage on top of a separate optimizer worker, keeps the same directives and the same filter names, and installs from the same signed repository your 1.15 packages came from. Your configuration carries over; what you gain is the worker.

What changes

In 1.15	In 2.1
The module optimizes in process	The module still serves and rewrites in process; the pagespeed-optimizer worker builds optimized variants beside it and the module serves them from the shared cache
One package per web server	The Apache module package depends on pagespeed-optimizer at the same version; one upgrade command moves both
A Cyclone volume under the module’s file-cache path	The module’s own cache stays where it was; the worker keeps its volume under /var/cache/pagespeed-optimizer/v2
X-Mod-Pagespeed / X-Page-Speed headers	Unchanged
Admin console at /pagespeed_admin	Unchanged, plus an Overview page and panels for the worker

Upgrade

# Debian / Ubuntu
sudo apt-get update
sudo apt-get install --only-upgrade mod-pagespeed            # Apache
sudo apt-get install --only-upgrade nginx-module-pagespeed   # nginx
# AlmaLinux / RHEL / Rocky
sudo dnf upgrade mod-pagespeed             # Apache
sudo dnf upgrade nginx-module-pagespeed    # nginx

The mod-pagespeed package depends on pagespeed-optimizer at the exact same version, so the Apache upgrade pulls the worker in. On nginx the worker is optional: sudo apt-get install pagespeed-optimizer (or dnf install) adds it, and two directives hand nginx’s in-place optimization to it; see Using the optimizer worker with nginx.

Then start things in order:

sudo systemctl restart pagespeed-optimizer   # the package starts it; make sure it is up
sudo systemctl restart apache2               # httpd on Enterprise Linux, or nginx

At boot the packaged unit orders the optimizer ahead of the web server and counts it as started only once its notification socket exists. During the upgrade itself, when you start things by hand, keep that order: optimizer first, web server second.

On Apache the package also installs pagespeed_daemon.conf (/etc/apache2/conf-available/ on Debian and Ubuntu, /etc/httpd/conf.d/ on the Red Hat family), which sets ModPagespeedDaemonSocketPath and ModPagespeedDaemonVolumePath to the worker’s defaults, so the module reaches the worker without editing any configuration. A file you created by hand earlier at that path stops an unattended Debian upgrade with a dpkg prompt; remove it before upgrading, or install with -o Dpkg::Options::=--force-confold to keep it.

The cache

Nothing is purged. A 1.15 install stores its cache in a Cyclone volume under the module’s file-cache path; the 2.1 optimizer opens its own volume under /var/cache/pagespeed-optimizer/v2 and never touches the old file. The first requests after the upgrade are misses and the cache refills as traffic arrives, so pick a quiet hour if your origin is sensitive to that. Both files exist during the upgrade, so the disk needs room for the second volume. The old file is what makes a rollback warm; delete it yourself once you are confident you will not roll back.

Platform notes

• IIS / Windows Server. The IIS package ships from the 1.15 packaging channel: run the current MSI over the existing install and iisreset. See Install on IIS.
• Debian 11 (bullseye). The repository’s bullseye suite carries the 1.15.0 module packages; the 2.1 packages need Debian 12 or newer.
• cPanel EasyApache 4 (EL8). The module runs without the optimizer worker.

Verify

curl -I http://localhost/ | grep -i -E 'X-Mod-Pagespeed|X-Page-Speed'

The header is unchanged. Open the admin console’s Overview page: the optimizer card reads Running once the module has reached the worker, and the Statistics page’s ipro_daemon_served rises as in-place requests are answered from the worker’s cache. Is it working? has the rest.

Roll back

Roll the module and pagespeed-optimizer back together to the 1.15 packages you ran; the old Cyclone volume reopens still warm unless you deleted it. Uninstall and rollback has the commands.