Add rule
Fill in the fields, then click OK.
- Rule Name
- The name of the rule that is set by you. This name can contain any
alphanumeric character, underscore, hyphen, or period. It can be from 1-to-20
characters and cannot contain any blanks.
- Rule Type
- You may choose from the following rule types:
- IP Address
Based on the client's IP address. Use this type of rule if you want to screen the customers and allocate
resources based on where they are coming from.
- Time of day
Based on the time of day. Utilized for capacity planning reasons. Example, if your Web site gets hit most
during the same period of time every day, you might want to dedicate more servers to HTTP during peak times
as opposed to slower times.
- Total Connections (per second
Based on the number of connections per second for the port. You may want to use rules based on total
connections per second if you need to share some of your servers with other applications.
- Active Connections (total)
Based on the total number of active connections for the port. You may want to use rules based on the total
active connections on a port if your servers get overloaded and start throwing packets away. Certain web
servers will continue to accept connections even though they do not have enough threads to respond to the
request. As a result, the client requests time out and the customer going to your Web site is not served.
Use rules based on active connections to balance capacity within a pool of servers.
- Content
A regular expression that is compared to the client requested URLs. You may want to use content type
rules to send requests to sets of servers specifically set up to handle some subset of your site's traffic.
Example, you may want to use one set of servers to handle all cgi-bin requests, another set to handle all streaming
audio requests, and a third set to handle all other requests. You would add one rule with a pattern that
matches the path to your cgi-bin directory, another that matches the file type of your streaming audio files,
and a third always-true rule to handle the rest of the traffic. You would then add the appropriate
servers to each of the rules.
- Always True
The rule will always be true. A rule may be created as "always true". Such a rule will always be
selected, unless all the servers associated with it are down. For this reason, it should ordinarily be at a
lower priority than other rules.
- Priority (optional)
- An integer representing the order in which rules are reviewed. If no priority
is given to the first rule you set, by default it is given a priority value of 1 and evaluated first.
The next rule will then be given a priority value of 11 and evaluated second, (last priority value + 10, in
this case 1 + 10), third rule = 21, fourth rule = 31, and so forth. The rules are evaluated in numerical
order, lower numbers take precedence over higher ones.
- Begin Range
- Optionally, the lower value in the range used to determine whether or not the rule
is true. If you are adding a rule based on:
- IP Address, then the begin range is the address of the client as either a symbolic name or in dotted-decimal format. The default is 0.0.0.0.
- Time, then the begin range is an integer. The default is 0, representing midnight.
- Total Connections, then the begin range is an integer. The default is 0.
- Active Connections, then the begin range is an integer. The default is 0.
You do not have to specify a begin range for an always-true rule.
- End Range
- Optionally, the upper value in the range used to determine whether or not the rule is true. If you are adding a rule based on:
- IP Address, then the end range is the address of the client as either a symbolic name or in dotted-decimal format. The default is 255.255.255.255.
- Time of day, then the end range is an integer. The default is 24, representing midnight.
- Total Connections, then the end range is an integer. The default is 2 to the 32nd power minus 1.
- Active Connections, then the end range is an integer. The default is 2 to the 32nd power minus 1.
You do not have to specify an end range for an always-true rule.
- Pattern
- Applicable only to Content rule. Enter the pattern syntax
you want to use, with the following restrictions:
- no spaces
- special characters: (unless you precede the character with a \)
* : wildcard (matches 0 to x of any character)
( : used for logic grouping
) : used for logic grouping
& : logical AND
| : logical OR
! : logical NOT
- reserved keywords (always followed by =):
Method : used by the HTTP protocol, in a translation,
to retrieve a request; example, GET, POST and
so forth.
UTI : path of the URL request
Version : specific version of the request, either
HTTP/1.0 or HTTP/1.1
Host : value from the host: header
Note: optional in HTTP/1.0 protocols
[key] : any valid HTTP header name that Dispatcher
can search for; example, User-Agent,
Connection, referer, and so forth.
Examples: A browser targeting http://www.company.com/path/webpage.htm might result in values such as
the following:
Method=GET
URI=/path/webpage.htm
Version=HTTP/1.1
Host=www.company.com
Connection=Keep-Alive
For more information regarding pattern syntax, as well as scenarios, please see the "Configure
rules-based load balancing" and the "Content rule (pattern) syntax" sections of the
Load Balancer Administration Guide.
- One or more server addresses: (optional)
- The list of server(s) currently defined for the port. You can optionally select one or more
from the list to be included with the rule.
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