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 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.
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.
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.
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.
The TCP reset feature sends a TCP reset to clients that are connected to servers that have weights of 0. A server's weight can be 0 if it is configured to 0 or if an advisor marks the server down.
Load Balancer requires information about all interfaces and IP addresses configured on a machine, and this information can be obtained manually or configured to be automatically updated.
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.
The smoothing index limits the amount that a server’s weight can change, effectively smoothing the change in the distribution of requests.
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.