Blog Sections Open
Shrinking an Oversized `modx_session` Table
If database backups suddenly become huge, the session table is often one of the first places to inspect.
Large Evolution or MODX installs sometimes surprise teams with a database backup that has suddenly crossed hundreds of megabytes or even a gigabyte. In the legacy case behind this post, the main cause turned out to be the session table.
What the Table Actually Stores
modx_session exists to keep user session data. On a busy site that is normal, but if sessions live too long, bots hit the site aggressively, or cleanup is weak, the table can grow far beyond what is useful.
What to Review First
- session lifetime settings
- whether bot traffic is creating excessive anonymous sessions
- whether expired sessions are being cleaned up reliably
- whether database-backed sessions are still the best storage choice for the project
Safe Mitigation Steps
- clear expired sessions on a schedule
- review bot filtering and rate limiting
- move session storage if the stack supports a better backend
- check whether heavy manager usage or custom login flows are writing more session data than expected
The important distinction is this: a large session table does not automatically mean the site is broken, but it can bloat backups, slow maintenance tasks, and indicate avoidable pressure on the application layer.
Why an Evolution CMS Site Fails on the First Visit but Loads After Refresh
A deeper look at the confusing first-hit failure where Evolution shows an install/config error on the first request but works after a refresh.
Caching Pages Selectively When GET Parameters Are Present
A practical rule for GET-aware caching: search pages and other high-cardinality query pages should usually stay uncached or use a strict allowlist.