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 may be from 1 to 20 characters and cannot contain any blanks.

Chose from the following rules:

  • 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.
  • Client port
    Based on the client's port. You may want to use this type of rule if your clients are using some kind of software that asks for a specific port from TCP/IP when making requests.
  • Type of service
    Based on content of the Type of Service (TOS) field in IP header.
  • Reserved bandwidth
    The reserved bandwidth rule allows you to load balance based on the number of kilobytes per second are being delivered by a set of servers. By setting a threshold (allocating a specified bandwidth range) for each set of servers throughout the configuration, you can control and guarantee the amount of bandwidth being used by each cluster-port combination.
  • Shared bandwidth
    If the amount of data transferred exceeds the limit for the reserved bandwidth rule, the shared bandwidth rule provides you the ability to recruit unused bandwidth available at the site. Based on the amount of bandwidth to share at either the cluster or executor level. If the value is zero, bandwidth cannot be shared.
    Note: Prior to configuring the shared bandwidth rule, you must specify the maximum amount of bandwidth (kilobytes per second) that can be shared at the executor or cluster level. If the value is zero, bandwidth can not be shared.

    Sharing bandwidth at the cluster level allows a maximum bandwidth specified to be consumed by the cluster.

    Sharing bandwidth at the executor level allows the entire Dispatcher configuration to share a maximum amount of bandwidth.

    Specify a maximum shared bandwidth value that does not exceed the total bandwidth (total server capacity) available.

  • Content (Applies only to those ports with cbr forwarding method protocol.)
    Based on the content of the HTTP headers in the client request. You will 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.
  • Always True
    An always true rule will always be selected, unless all the servers associated with it are down. For this reason, it should typically be set at a lower priority than other rules. (Think of it as an else statement in programming logic.)

For more information regarding rules-based load balancing, please refer to the "Configure rules-based load balancing" section of the Load Balancer Administration Guide.

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 is then 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 taking precedence over higher ones.

Begin Range
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.
  • Client Port, then the begin range is an integer. The default is 0.
  • Reserved Bandwidth, then the begin range is an integer. The default is 0.
You do not have to specify a begin range for an always true, shared bandwidth, type of service or content rule.

End Range
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, 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.
  • Client Port, then the end range is an integer. The default is 65535.
  • Reserved Bandwidth, then the end range is an integer. The defaults is 2 to the 32nd power minus 1.
You do not specify an end range for an always true, shared bandwidth, type of service (TOS) or content rule.

TOS (Valid only for Type of service rule)
8-bit entry value consisting of 0, 1, or x.

Level to evaluate (Valid only for Total connections, and Active connections rules.)
Choose between evaluating all of the servers on the port or only the servers on the rule.

Level to share available bandwidth (Valid only for Shared bandwidth rule)
Set the level at which you want bandwidth to be shared. Choose the cluster or executor level (you must set the shared bandwidth on the executor or on the cluster before you can add an executor-level or cluster-level shared bandwidth rule or on the cluster before you can add a cluster-level shared bandwidth rule).

One or more server addresses: (optional)
The list of servers you have running. Optionally, select one or more from the list to be included with the rule.

Pattern
Applicable only if you select Content for the rule type. Type the desired pattern syntax using 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.
    URI      : 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.