Coyote Point Systems E350GX, Installation And Administration Manual

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Chapter 8: Using Match Rules
234 Equalizer Installation and Administration Guide
Server Selection Based on Content Type Using Match Rules
In this example, assume a configuration that has dedicated one or more servers to return only image files ( .gif , .jpg ,
etc.), while the remainder of the servers return all the other content for client requests.
We want to direct all requests for images to a particular set of server, and balance the remainder of requests across
the other servers in the cluster. The image servers are all connected to a common storage device that contains the
images. The remaining servers are all dedicated to serving particular content for different web sites. For this
example, we assume that a cluster with five servers as shown below has already been defined
Figure 49 Match Rule Example: Dedicated Image and Content Servers
We want to maintain persistent connections for the web site servers, assuming that some of the websites may need to
maintain sessions for applications such as shopping carts, email, etc. Persistent connections are not necessary for the
image servers, since they access the images from common storage and have no need to maintain client sessions, so
there is no need to incur the performance impact of maintaining session information.
To do this, we’ll create two match rules, as follows:
1. Log into the Administrative Interface using a login that has
add/del
access for the cluster (see “Logging In” on
page 52).
2. In the left frame, click the name of the Layer 7 cluster to which you want to add the rule. The cluster
Configuration
screen appears in the right frame:
a. Make sure that the
once only
flag is not checked; otherwise, uncheck the
once only
flag and click
commit
.
b. Open the
Persistence
tab and make sure the
persist
flag is not checked; otherwise, uncheck the
persist
flag and click
commit
.
This is necessary because these flags, if enabled, cause only the first request in a connection to be evaluated.
Since we want content to come from one set of servers and images from another, we want the servers that will
have persistent connections to be chosen by the match rules.
3. Right-click the cluster name in the left frame and select
Add Match Rule
. The
Add Match Rule
dialog appears:
a. Type
images
into the
match name
text box. In this match rule, we’ll construct an expression that will
match all the filename extensions of the images to be served. These requests will go to the image servers.
b. In our example, we want all the images to be served from either sv_19 or sv_19457 . In the
servers
field,
select
sv_19
,
sv_19457
using the Ctrl or Shift .
c. Select
commit
.
The match rule is created, added to the object tree, and its
Configuration
tab is opened: