Logical pool distribution

 

The Logical pool distribution (LPD) thread pool mechanism implements a strategy for improving the performance of requests that have shorter run times. Do not configure LPD unless you have already configured it in a previous release of WAS. LPD is a deprecated function and will be removed in a future version of the product.

The need for LPD is indicated by a mixture of EJB requests where the run times vary across the request types, and the ORB thread pool must be constrained for performance reasons. In this case, longer run time requests might tend to prolong the response times for shorter requests by denying them adequate access to threads in the thread pool. LPD provides a mechanism that allows shorter requests greater access to the threads. LPD divides the Object Request Broker (ORB) thread pool into logical pools, as configured by the administrator using ORB custom properties starting that start with the following:

com.ibm.websphere.threadpool.strategy.*

The size of each pool is a percentage of the maximum number of ORB threads. The sum of the logical pool percentages must equal 100.

When LPD is active, incoming ORB requests are vectored, or pointed, to a pool based on historical run time history for the request type. The request type is determined by the method, which is qualified internally as unique across components. The LPD mechanism adjusts pool targets at runtime to optimize the distribution of requests across logical pools.

The LPD mechanism can be tuned after it is enabled. Response time, throughput measurements, and statistics produced by the LPD mechanism drive the tuning process.

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Related tasks

Manage Object Request Brokers

 

Related Reference

Object Request Broker custom properties