SQUID(8) BSD System Manager's Manual SQUID(8)NAMEsquid - caching HTTP proxy and accelerator with virtual host support
SYNOPSISsquid [-hsvzCDRUVY] [-f config-file] [-[au] port] [-k signal]
DESCRIPTIONsquid is an HTTP cache. It can be configured in either proxy or acceler-
ator modes.
In proxy mode squid handles HTTP requests from ``downstream'' HTTP
clients. Where possible these requests are satisfied out of the cache.
This mode reduces the traffic on the ``upstream'' network caused by HTTP
clients using the proxy. A proxy can be of significant benefit where the
upstream link is either expensive or congested.
In accelerator mode squid handles HTTP request from ``upstream'' HTTP
clients. Where possible these requests are satisfied out of the cache.
This mode reduces the traffic on internal networks and can result in
faster response times than those provided by common HTTP servers.
squid has extensive facilities to control the caching policy. These fa-
cilities are configured and documented in the configuration file,
/var/www/conf/squid.conf.
squid supports the following command line options:
-a port Specify HTTP port number (default: 3128).
-b Buffer log output (default is unbuffered).
-f file Use given config-file instead of /var/www/conf/squid.conf.
-h Print help message.
-i Disable IP caching.
-k reconfigure|rotate|shutdown|interrupt|kill|debug|check
Send signal to running copy and exit.
-s Enable logging to syslog.
-u port Specify ICP port number (default: 3130), disable with 0.
-v Print version.
-z Zap disk storage -- deletes all objects in disk cache.
-C Do not catch fatal signals.
-D Disable initial DNS tests.
-F Foreground fast store rebuild.
-R Do not set REUSEADDR on port.
-U Unlink expired objects on reload.
-V Run HTTP accelerator in virtual host mode.
-Y Only return UDP_HIT or UDP_DENIED during store reload.
squid is started at boot time by /etc/rc if the configuration file
/var/www/conf/squid.conf exists.
SIGNALS
The following signals can be used to control a running squid process:
SIGUSR1 rotates log files.
SIGHUP reread configuration file.
See also the -k command line option.
FILES
/var/www/conf/squid.conf squid configuration file, currently the
best source of documentation of the squid
configuration directives. squid is started
automatically at boot time if this file ex-
ists.
/var/log/squid/access.log Log of accesses to the cache.
/var/log/squid/cache.log squid messages are logged here.
/var/log/squid/hierarchy.log Log of actions taken while fetching a re-
quested object.
/var/log/squid/store.log Log of actions taken by the storage manag-
er.
/var/run/squid.pid Holds the PID of the running squid.
/var/www/squid/bin/cachemgr
/var/www/squid/cache On disk storage of cached objects.
/var/www/squid/bin/dnsserver Process to handle DNS requests (prevents
squid from blocking on slow DNS responses).
/var/www/squid/bin/ftpget Process to handle FTP requests.
SEE ALSOcachemgr(8), client(8), squid.conf(5), dnsserver(8), ftpget(8),
squid-users mailing list (send e-mail to squid-users-request@nlanr.net to
subscribe).
HISTORYsquid is a derivative of the Harvest cached.
Bugs
Since squid keeps ``hot'' data and objects in memory the data segment of
a busy cache can grow quite large. There are two potential consequences
of this:
1. If the size of the data segment exceeds the resource allocation of
the process squid will die (if this is happening you will see a mes-
sage in /var/log/squid/cache.log about being unable to allocate mem-
ory). The solution to this problem is to increase the data segment
size allowed to squid. Typically this will be done by increasing
the datasize allocation in the daemon class in /etc/login.conf.
2. If the machine does not have adequate memory to support the traffic
seen by the cache it will start swapping and performance will be
severely degraded.
AUTHORS
Duane Wessels <wessels@nlanr.net>, K. Claffy <kc@nlanr.net>, and Hans-
Werner Braun <hwb@nlanr.net>.
BSDI BSD/OS 18 Jul 1996 2