fasthtcacheclean - A Faster Apache Disk Cache Cleaner

A replacement for apache-htcacheclean, which is faster in cleaning the disk cache.

It is primarily designed for disk caches on a separate partition or RAM disk.

Only unixoid operating systems like Linux are supported. Daemon mode is currently not supported. It has to be run via a systemd timer or a cronjob.

Building and Installation

To build it, cargo is required:

	sudo apt install cargo

Then fasthtcacheclean can be built with

	cargo build --release

The result can be found in target/release/fasthtcacheclean.

To install it:

cp target/release/fasthtcacheclean /usr/local/bin/
cp fasthtcacheclean.{service,timer} /etc/systemd/system/
systemctl daemon-reload
systemctl stop apache-htcacheclean
systemctl disable apache-htcacheclean
systemctl enable fasthtcacheclean.timer
systemctl start fasthtcacheclean.timer

Functionality

It works similarily to apache-htcacheclean in non-daemon mode with some optimizations and parallelization:

1. First it checks if the set limit was exceeded or is nearly reached. Starting with 90 % of the limit, the first files are deleted.
2. Old temporary files in the cache main directory are deleted (if modified more than 15 minutes ago).
3. Then the directory tree is scanned (by default using CPUs/2 threads in parallel). Old empty directories and orphaned .data files are deleted directly. Cache entries are sorted by expiry date, access date and modification date into a priority queue. To keep the RAM usage low, only the oldest up to 1'000'000 entries are kept for step 4.
4. The found cache entries are deleted until disk usage is 99.0 to 99.5 % of the limit. If more than 105 % of the limit were used, header file deletion happens more agressively.