Apache::LoadAvgLimit - limiting client request by system CPU load-averages

NAME

Apache::LoadAvgLimit - limiting client request by system CPU load-averages

SYNOPSIS

  in httpd.conf, simply
  <Location /perl>
    PerlInitHandler Apache::LoadAvgLimit
    PerlSetVar LoadAvgLimit 2.5
  </Location>
  or fully
  <Location /perl>
    PerlInitHandler Apache::LoadAvgLimit
    PerlSetVar LoadAvgLimit_1 3.00
    PerlSetVar LoadAvgLimit_5 2.00
    PerlSetVar LoadAvgLimit_15 1.50
    PerlSetVar LoadAvgRetryAfter 120
  </Location>

DESCRIPTION

If system load-average is over the value of LoadAvgLimit*, Apache::LoadAvgLimit will try to reduce the machine load by returning HTTP status 503 (Service Temporarily Unavailable) to client browser.

Especially, it may be useful in <Location> directory that has heavy CGI, Apache::Registry script or contents-handler program.

PARAMETERS

LoadAvgLimit

When at least one of three load-averages (1, 5, 15 min) is over this value, returning status code 503.

LoadAvgLimit_1, LoadAvgLimit_5, LoadAvgLimit_15

When Each minute's load-averages(1, 5, 15 min) is over this value, returning status code 503.

LoadAvgRetryAfter

The second(s) that indicates how long the service is expected to be unavailable to browser. When this value exists, Retry-After field is automatically set.

AUTHOR

Okamoto RYO <ryo@aquahill.net>

SEE ALSO

mod_perl(3), Apache(3), getloadavg(3), uptime(1), RFC1945, RFC2616

 Apache::LoadAvgLimit - limiting client request by system CPU load-averages