The limit Statement

Syntax

limit <value> {
    [ statements ]
}

Description

The limit statement limits the number of requests which are actively being processed through a section. If too many requests are being processed through the limit section, it immediately returns fail.

The <value> text can be a number, or a dynamic expansion, or an attribute reference. The contents of <value> are interpreted as an integer uint32 data type.

Example

limit 4 {
    foo
    bar
}

In general, the best way to use limit is in conjunction with a redundant block. In the following example, the configuration allows 4 packets to be outstanding in the proxy module. If more than 4 packets are outstanding, or if the proxy module fails, the detail module is called.

Example using redundant

redundant {
    limit 4 {
        proxy
    }

    detail
}

Limit with catch

In the following example, the configuration limits the concurrent proxy requests to a maximum of 4. If the limit is hit, it returns fail, which then runs catch fail, and writes to the detail file instead.

Example using catch

recv Access-Request {
    try {
        limit 4 {
            proxy
        }
    }
    catch fail {
        detail
    }
}