From: tfheen Date: Tue, 23 Sep 2008 11:58:53 +0000 (+0000) Subject: Update man page a bit X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84afa93d93c26cf647f49b9e22d4e0f6af0d715a;p=varnish Update man page a bit * Directors * Probing and backend health * vcl_hash * Updates for 2.0 (backend.host => .host; insert => deliver) git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3214 d4fa192b-c00b-0410-8231-f00ffab90ce4 --- diff --git a/varnish-cache/man/vcl.7so b/varnish-cache/man/vcl.7so index b34b3bad..697138be 100644 --- a/varnish-cache/man/vcl.7so +++ b/varnish-cache/man/vcl.7so @@ -92,6 +92,78 @@ if (req.http.host ~ "^(www\.)?example.com$") { set req.backend = www; } .Ed +.Ss Directors +Directors choose from different backends based on health status and a +per-director algorithm. +There currently exists a round-robin and a random director. + +Directors are defined using: +.Bd -literal -offset 4n +director b2 random { + .retries = 5; + { + /* We can refer to named backends */ + .backend = b1; + .weight = 7; + } + { + /* Or define them inline */ + .backend = { + .host = "fs2"; + } + .weight = 3; + } +} +.Ed +.Ss The random director +The random director takes one per-director option +.Fa .retries . +This specifies how many tries it will use to find a working backend. +The default is the same as the number of backends defined for the +director. + +There is also a per-backend option: weight which defines the portion +of traffic to send to the particular backend. +.Ed +.Ss The round-robin director +The round-robin does not take any options. +.Ed +.Ss Backend probes +Backends can be probed to see whether they should be considered +healthy or not. The return status can also be checked by using +.Fa req.backend.healthy +. +.Fa .window +is how many of the latest polls we examine, while +.Fa .threshold +is how many of those must have succeeded for us to consider the +backend healthy. +.Bd -literal -offset 4n +backend www { + .host = "www.example.com"; + .port = "http"; + .probe = { + .url = "/test.jpg"; + .timeout = 0.3 s; + .window = 8; + .threshold = 3; + } +} +.Ed +It is also possible to specify the raw HTTP request. +.Bd -literal -offset 4n +backend www { + .host = "www.example.com"; + .port = "http"; + .probe = { + # NB: \\r\\n automatically inserted after each string! + .request = + "GET / HTTP/1.1" + "Host: www.foo.bar" + "Connection: close"; + } +} +.Ed .Ss ACLs An ACL declaration creates and initializes a named access control list which can later be used to match client addresses: @@ -245,7 +317,9 @@ Proceed with pass mode. .El .\" vcl_hash .It Cm vcl_hash -Currently not used. +Use +.Cm req.hash += req.http.Set-Cookie +or similar to include the Set-Cookie HTTP header in the hash string. The .Cm vcl_hash subroutine may terminate with one of the following keywords: @@ -313,10 +387,12 @@ request. Switch to pass mode. Control will eventually pass to .Cm vcl_pass . -.It Cm insert -Insert the object into the cache, then deliver it to the client. +.It Cm deliver +Possibly insert the object into the cache, then deliver it to the client. Control will eventually pass to .Cm vcl_deliver . +.It Cm esi +ESI-process the document which has just been fetched. .El .\" vcl_deliver .It Cm vcl_deliver @@ -381,9 +457,9 @@ The current time, in seconds since the epoch. .Pp The following variables are available in backend declarations: .Bl -tag -width 4n -.It Va backend.host +.It Va .host Host name or IP address of a backend. -.It Va backend.port +.It Va .port Service name or port number of a backend. .El .Pp @@ -405,6 +481,8 @@ The requested URL. The HTTP protocol version used by the client. .It Va req.backend The backend to use to service the request. +.It Va req.backend.healthy +Whether the backend is healthy or not. .It Va req.http. Ns Ar header The corresponding HTTP .Ar header . @@ -502,8 +580,8 @@ specified. .\" Keep this in synch with bin/varnishd/mgt_vcc.c and etc/default.vcl .Bd -literal -offset 4n backend default { - set backend.host = "backend.example.com"; - set backend.port = "http"; + .host = "backend.example.com"; + .port = "http"; } .so default.vcl @@ -514,13 +592,13 @@ separate backends in the same Varnish instance, by selecting backends based on the request URL. .Bd -literal -offset 4n backend www { - set backend.host = "www.example.com"; - set backend.port = "80"; + .host = "www.example.com"; + .port = "80"; } backend images { - set backend.host = "images.example.com"; - set backend.port = "80"; + .host = "images.example.com"; + .port = "80"; } sub vcl_recv {