Coyote Point Systems Equalizer, Installation And Administration Manual

Page: 89 / 144

Specifying Layer 7 Rules
Equalizer Installation and Administration Guide 79
c. Select the Quiesce Server checkbox.
d. Click Set to save your changes.
2. If the server belongs to an L4 cluster, simply set its weight to 0. This prevents Equalizer
from routing new connections to the server.
3. Wait until there are no active connections and the server's idle time is greater than the
your application’s session lifetime before taking the server offline. To check these
values, click the name of the server to view the Server Parameters.
Deleting a Server
To delete a server endpoint from a virtual cluster:
1. Log into the Equalizer Administration interface with edit access.
2. In the left frame, click the name of the server you want to remove.
3. Select Delete Server from the local menu in the Server Parameters frame.
4. When prompted, confirm that you want to remove the server from the cluster by
clicking the OK button.
If you are deleting a server with active connections, a confirmation dialog is displayed.
Click Force to remove the server anyway. This removes the server, deleting the active
connections and the user sessions they represent. Click Cancel to cancel the operation.
Specifying Layer 7 Rules
Equalizer’s support for Layer 7 content-sensitive load balancing, enables you to define
match rules for routing HTTP and HTTPS requests according to the content of the request.
For each virtual cluster, you can specify any number of match rules. For each match rule,
you then specify the subset of servers that can handle requests that meet the rule criteria.
A match rule consists of a match expression and a then clause that identifies the operations to
perform if the expression is satisfied by the request. A match is specified as:
match { expression } then { then_clause }
A basic match expression consists of a request attribute, a comparison operator, and a
value. The request attributes correspond to elements in the request header. For example, a
request for a web page might look like this:
Get /somedir/somepage.html http/1.1
Accept: text/html, text/*, *.*
Accept-Encoding: gzip
Host: www.somesite.com
User-Agent: Mozilla/4.7 [en] (Win98; U)
By using the request attributes to construct match expressions, you can route requests
based on the URI and host information contained in the request. The path name, directory
name, and file name attributes are based on the value of the request URI. For example, the
value of the file name attribute for this request would be
somepage.html
, the value of the
directory name attribute would be
/somedir
, and the value of the pathname attribute would