How well a Web site performs while receiving heavy user
traffic is an essential factor in the overall success of an organization.
This topic highlights a few main ways you can improve performance
through a combination of product features and application development
considerations.
- The manager report
- The manager function of Load Balancer calculates a weight for
each server. These weights are used to determine how many connections
a server should receive as compared with the other servers in the
same cluster and port configuration. Understanding the manager report
is critical to understanding how the network traffic is distributed.
- Optimizing the manager interval
- To optimize overall performance, the manager is restricted in
how often it can interact with the executor. You can make changes
to this interval by entering the dscontrol manager interval and dscontrol
manager refresh commands.
- Tuning the proportion of importance given to status information
- The manager uses ratios to determine the importance of status
information coming from advisors and Load Balancer. You can change
the default ratios that the manager uses to weight this information.
- Managing traffic with server weights
- Weights are applied to all servers on a port. For any particular
port, the requests are distributed between servers based on their
weights relative to each other. For example, if one server is set
to a weight of 10, and the other to 5, the server set to 10 should
get twice as many requests as the server set to 5.
- Optimizing the sensitivity threshold
- To work at top speed, updates to the weights for the servers are
only made if the weights have changed significantly. Constantly updating
the weights when there is little or no change in the server status
could create unnecessary overhead.
- Optimizing the smoothing index
- The smoothing index limits the amount that a server's weight
can change, effectively smoothing the change in the distribution of
requests.
- Controlling connection records with the staletimeout value
- Connections are considered stale when there has been no activity
on that connection for the number of seconds specified in stale timeout.
When the number of seconds has been exceeded with no activity, Load
Balancer will remove that connection record from its tables, and subsequent
traffic for that connection is discarded. The staletimeout command
controls the way Load Balancer handles idle connections and the associated
connection records.