Coyote Point Systems Equalizer GX Series, Administration Manual

Page: 649 / 866

Setting ACV Query and Response Strings
Specifying an ACV Query and an ACV Response String basically automates the exchange shown in
Active Content Verification (ACV) Probes . Equalizer uses the probe string to request data from
each server. To verify the server’s content, searches the returned data for the response string.
For example, you can use “
GET /index.html
” as the ACV Query and you can set the Response
String to some text, such as “
Welcome
” in the example in Active Content Verification (ACV) Probes ,
which appears on the home page.
Similarly, if you have a Web server with a PHP application that accesses a database, you can use
ACV to ensure that all of the components in the application are working. You could set up a PHP
page called
test.php
that accesses the database and returns a page containing
ALL OK
if there are
no problems.
For most applications, only an ACV response string is needed - Equalizer connects to the probe
port on the server instance and waits for a response.
Some applications may require input on the connection before a response is sent back to
Equalizer. The ACV query string is used for this purpose - if it is non-empty, the ACV query string
is sent after the server instance connection is established.
An ACV query or response string:
l
Must be enclosed in single or double quotes if it contains a space character.
l
Any single or double quotes included within the string must be preceded by the backslash
character (\).
Note
-In ACV Query strings character escapes such as “\n” for new-line, “\r” for carriage return and “\t” for Tab are
supported. "\r" and "\n" must be manually inserted at the end of all HTTP and HTTPS ACV probes.
For ACV Response strings Regular Expression matching is supported.
Setting the ACV Query and Response Strings in the GUI
Enter the following values on the
Server Pool > Configuration > LB Policy>
screen:
1. Verify that you are logged into the GUI. If not, log in as described in
"Logging In"
on page
230.
2. Select the
Load Balance
configuration tab on the left navigational pane if it is not already
selected.
3. Click on the arrow beside
Server Pools
to expand the branch.
4. Select a server pool from the Server Pool branch.
5. Enter an
ACV Query
and
ACV Response
string.The response string should be text that appears
only in a valid response. This string is also case-sensitive. An example of a poorly chosen
string would be
HTML
, since most web servers automatically generate error pages that con-
tain valid HTML.
6. Click on
Commit
to save the settings.
Copyright © 2014 Coyote Point Systems, A Subsidiary of Fortinet, Inc.
All Rights Reserved. 649
Equalizer Administration Guide