yuya9786/cachectl

Page cache controller for regular file in Go

cachectl

cachectl is a controller for regular file's page cache.

Dependency

posix_fadvise is required.

Installation

go get -u github.com/cubicdaiya/cachectl/...

If you don't have go-runtime, you may download the binary from here.

Show page cache stat for file

cachectl -f /var/log/access_log

Purge page cache for file

cachectl -op purge -f /var/log/access_log

If you want to leave a cache appended recently, assigning a rate for purging page cache with -r is recommended.

cachectl -op purge -f /var/log/access_log -r 0.9

cachectld

cachectld is a daemon for scheduled purging page cache. Its behavior is described by TOML.

cachectld -c conf/cachectld.toml

Configuration for cachectld

A configuration for cachectld has one or multiple targets.

name	type	description	default	note
path	string	target file path		directory or file path
purge_interval	int	interval for purging page cache for file	3600	unit is second. if -1 is set, purge does not run.
filter	string	filtering pattern string for target file path	.*	regular expression with golang's regexp package
rate	float	rate of purging page cache for file	0.0	0.0 and 1.0 is same behavior (0.0 <= rate <= 1.0)

A example is below.

[[targets]]
path = "/vagrant/cachectl.go"
purge_interval = 30

[[targets]]
path = "/vagrant/cachectld.go"
purge_interval = 20

[[targets]]
path = "/vagrant/cachectl"
purge_interval = 5
filter = "\\.go$"
rate = 0.9

Signal trigger

From v0.3.0, you can trigger with SIGUSR1 to run the targets for cachectld.

$ pkill -USR1 cachectld

When SIGUSR1 is received, cachectld runs all targets including the targets purge_interval is set -1.

License

Copyright 2014-2016 Tatsuhiko Kubo

Licensed under the MIT License.