Re: How shoud I set refresh_pattern option in squid?

Madjid SalimZadeh wrote:
>
> There are some refresh_patterns in my squid configuration files. Can
> anyone tell me what does it mean? What are the first and second numbers?

The first is the time (in minutes) an object without an explicit expiry
time should be considered fresh. The recommended value is 0, any higher
values may cause dynamic applications to be erronously cached unless the
application designer has taken the appropriate actions.

The second is a percentage of the objects age (time since last
modification age) an object without explicit exipry time will be
considered fresh.

The last is an upper limit on how long objects without an explicit
expiry time will be considered fresh.

> refresh_pattern -i . 10800 50% 48000
> refresh_pattern -i \.gif$ 10800 50% 48000
>
> How can I set refresh_pattern if I want my gif files never expire and
> always be in cache . or some files stay in cache longer?
>
> How can I use override-expire , override-reload , ignore-reload option in
> refresh_pattern and what does each one of these options do?

override-lastmod makes the min age (first value) apply even if it is
known that the object has been modified recently.

All the other options are various overrides to the HTTP/1.1
specification. Any use of these are stronly discouraged.

override-expire makes the min age override any explicit expiry time set
by the origin server.

reload-into-ims changes any "Pragma: no-cache" request into
"If-Modified-Since" revalidations if the object in question is cached.

ignore-reload makes Squid ignore any "Pragma: no-cache" headers sent in
the request.

See RFC2616 for explanations of the terms used here.

--
Henrik Nordstrom
Spare time Squid hacker