In the proportional algorithm, requests are distributed to attached data sources according to the following criteria:
The type of request
The weight of the data source as a ratio of the total weights of the other data sources in the pool
The cumulative load since the last startup of Directory Proxy Server
After startup, the first request of a given type is distributed to the data source with the highest weight for that type of request. Directory Proxy Server continues to distribute the requests in proportion to the weight of each data source for that type of request.
If a data source becomes unavailable, Directory Proxy Server distributes the requests to remaining data sources in proportion to their weight.
The following figure illustrates how Directory Proxy Server distributes the first eight search requests to a pool of data sources with different weights. The data source with a weight of 2 processes twice as many requests as the data sources with a weight of 1.
For an example of how configure the proportional algorithm, see To Configure the Proportional Algorithm for Load Balancing in Sun Java System Directory Server Enterprise Edition 6.2 Administration Guide.