IBM E02HMLL-I Implementation Guide - Page 293

Caching static relationships You can cache static relationships so that the participant data they contain is loaded into memory and any queries for the data are issued against the in-memory data, rather than in the data stored in the database. This can make the relationship lookups much faster than if they had to retrieve the information from the database for each flow. For more information on configuring static relationships to be cached, see the Map Development Guide. Using database connection pools It is common to have to retrieve or insert information into a database table during the processing of a flow. Performance is impacted if the interface must establish a connection to the database for each flow, particularly because the log in process must be performed for each connection. Database connection pools are integration components that establish and maintain a pool of connections to a database resource. The connections are established initially and are available to other components to issue queries against the database resource. When a component is done using a connection, the connection is released and returned to the pool so that another component may use it. This eliminates the need to log in each time a connection is required. For information on how to create database connection pools, see Chapter 8, "Configuring database connection pools," on page 145. For information on how to use database connection pools in maps, see the Map Development Guide. For information on how to use database connection pools in collaboration templates, see the Collaboration Development Guide. Using the memory checker thread InterChange Server Express features a memory checker thread that you can use to regulate how events are processed by the system and thereby regulate the consumption of system memory. This can mitigate the risk of system crashes due to lack of memory. The memory checker thread periodically measures the amount of memory used by InterChange Server Express and evaluates if it is within an acceptable configured range. If memory usage is not within an acceptable range then the memory checker thread manages system components to reduce the memory usage. If the memory usage exceeds a lower threshold specified by the lower threshold then the memory checker thread causes the event listener threads of the connector controllers in the system to sleep for a configurable maximum amount of time. The amount of time varies depending on how much the memory usage exceeds the lower threshold, but does not exceed the amount of time specified by the Connector pause time at threshold property. By causing the event listener threads to sleep in this way, the memory checker thread slows down the rate at which events are delivered to InterChange Server Express and reduces the risk of the upper memory threshold being exceeded. If the memory usage exceeds the upper threshold specified by the Memory lower threshold percent property then the memory checker thread pauses the connectors in the system. When connectors are paused they continue to process business Chapter 14. Performance tuning 281