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Web OS 10.0 Application Guide
Weights for Real Servers
Weights can be assigned to each real server. These weights bias load balancing to give the fast-
est real servers a larger share of connections. Weight is specified as a number from 1 to 48.
Each increment increases the number of connections the real server gets. By default, each real
server is given a weight setting of 1. A setting of 10 would assign the server roughly 10 times
the number of connections as a server with a weight of 1. To set weights, enter the following
commands:
>> # /cfg/slb/real <real server number>
>> Real server# weight 10
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Connection Time-outs for Real Servers
In some cases, open TCP/IP sessions might not be closed properly (for example, the switch
receives the SYN for the session, but no FIN is sent). If a session is inactive for 10 minutes (the
default), it is removed from the session table in the switch. To change the time-out period,
enter the following:
>> # /cfg/slb/real <real server number>
>> Real server# tmout 4
The example above would change the time-out period of all connections on the designated real
server to four minutes.
Maximum Connections for Real Servers
You can set the number of open connections each real server is allowed to handle for SLB. To
set the connection limit, enter the following:
>> # /cfg/slb/real <real server number>
>> Real server# maxcon 1600
Values average from approximately 500 HTTP connections for slower servers to 1500 for
quicker, multiprocessor servers. The appropriate value also depends on the duration of each
session and how much CPU capacity is occupied by processing each session. Connections that
use a lot of Java or CGI scripts for forms or searches require more server resources and thus a
lower maxcon limit. You may wish to use a performance benchmark tool to determine how
many connections your real servers can handle.
When a server reaches its maxcon limit, the switch no longer sends new connections to the
server. When the server drops back below the maxcon limit, new sessions are again allowed.
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Chapter 6: Server Load Balancing
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Weights are not applied when using the hash or minmisses metrics.
(Select the real server)
(10 times the number of connections)
(Select the real server)
(Specify an even numbered interval)
(Select the real server)
(Allow 1600 connections maximum)
212777-A, February 2002
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