[Varnish] #793: TTL randomizing

Varnish varnish-bugs at varnish-cache.org
Fri Oct 8 12:21:31 CEST 2010

#793: TTL randomizing
 Reporter:  tmagnien     |       Owner:  phk                     
     Type:  enhancement  |      Status:  new                     
 Priority:  normal       |   Milestone:                          
Component:  varnishd     |     Version:  trunk                   
 Severity:  normal       |    Keywords:  expiry randomization ttl

 Here is a vmod patch to allow TTL randomization. This can be used to avoid
 the "lemming effect" described [http://www.varnish-
 cache.org/trac/wiki/PostTwoShoppingList#Expiryrandomization here].

 Use in VCL :

 sub vcl_fetch {
         set beresp.ttl = std.randomize_ttl_by(beresp.ttl, 50);

 Will randomize all TTLs by 50%.


Ticket URL: <http://varnish-cache.org/trac/ticket/793>
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The Varnish HTTP Accelerator

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