[master] 5c798e2 Improve examples and reduce duplicated information
Federico G. Schwindt
fgsch at lodoss.net
Wed Sep 3 16:53:40 CEST 2014
commit 5c798e215dedf244249d4aa6d82a1aaa3fe453d9
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date: Wed Sep 3 14:52:37 2014 +0100
Improve examples and reduce duplicated information
diff --git a/doc/sphinx/reference/vcl.rst b/doc/sphinx/reference/vcl.rst
index 6828f99..90ac019 100644
--- a/doc/sphinx/reference/vcl.rst
+++ b/doc/sphinx/reference/vcl.rst
@@ -213,6 +213,8 @@ are available:
Backends can be used with *directors*. Please see the
vmod_directors(3) man page for more information.
+.. _reference-vcl_probes:
+
Probes
------
diff --git a/doc/sphinx/users-guide/vcl-backends.rst b/doc/sphinx/users-guide/vcl-backends.rst
index 5d31e77..1a1f556 100644
--- a/doc/sphinx/users-guide/vcl-backends.rst
+++ b/doc/sphinx/users-guide/vcl-backends.rst
@@ -156,14 +156,14 @@ Health checks
-------------
Lets set up a director with two backends and health checks. First let
-us define the backends.::
+us define the backends::
backend server1 {
.host = "server1.example.com";
.probe = {
.url = "/";
+ .timeout = 1s;
.interval = 5s;
- .timeout = 1 s;
.window = 5;
.threshold = 3;
}
@@ -173,40 +173,23 @@ us define the backends.::
.host = "server2.example.com";
.probe = {
.url = "/";
+ .timeout = 1s;
.interval = 5s;
- .timeout = 1 s;
.window = 5;
.threshold = 3;
}
}
-What is new here is the ``probe``. Varnish will check the health of each
-backend with a probe. The options are:
-
-url
- The URL Varnish will use to send a probe request.
-
-interval
- How often should we poll.
-
-timeout
- What is the timeout of the probe.
-
-window
- Varnish will retain up to this many probes when considering backend health.
-
-threshold
- How many of the `.window` last polls must be good for the backend to be
- declared healthy.
-
-initial
- How many of the probes that needs to be succesful when Varnish starts.
- Defaults to the same amount as the threshold.
+What is new here is the ``probe``. In this example Varnish will check the
+health of each backend every 5 seconds, timing out after 1 second. Each
+poll will send a GET request to /. If 3 out of the last 5 polls succeeded
+the backend is considered healthy, otherwise it will be marked as sick.
+Refer to the :ref:`reference-vcl_probes` section in the
+:ref:`reference-vcl` documentation for more information.
Now we define the 'director'::
-
import directors;
sub vcl_init {
@@ -215,17 +198,16 @@ Now we define the 'director'::
vdir.add_backend(server2);
}
+You use this `vdir` director as a backend_hint for requests, just like
+you would with a simple backend. Varnish will not send traffic to hosts
+that are marked as unhealthy.
-You use this `vdir` director as a backend_hint for requests, just like you would
-with a simple backend. Varnish will not send traffic to hosts that are marked as
-unhealthy.
-
-Varnish can also serve stale content if all the backends are
-down. See :ref:`users-guide-handling_misbehaving_servers` for more
-information on how to enable this.
-
-Please note that Varnish will keep health probes running for all loaded VCLs. Varnish
-will coalesce probes that seem identical - so be careful not to change the
-probe config if you do a lot of VCL loading. Unloading the VCL will discard the
-probes. For more information on how to do this please see ref:`reference-vcl-director`.
+Varnish can also serve stale content if all the backends are down. See
+:ref:`users-guide-handling_misbehaving_servers` for more information on
+how to enable this.
+Please note that Varnish will keep health probes running for all loaded
+VCLs. Varnish will coalesce probes that seem identical - so be careful
+not to change the probe config if you do a lot of VCL loading. Unloading
+the VCL will discard the probes. For more information on how to do this
+please see ref:`reference-vcl-director`.
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