The administrator can configure the Factory service to change the BIRT data result set buffer, and the design and document caches by choosing Server Configuration Templates—Settings—Factory Service—Java Factory Service—Caching, as shown in Figure 7‑7. These topics are discussed in the following sections:

A memory-based buffer stores the data result set for a BIRT data object generation query. The Factory sorts, groups, and aggregates data in the buffer. By default this buffer is 128 MB. If the buffer is too small, iHub writes the data result sets to disk. Change this property to tune BIRT document generation performance on iHub under the following conditions:

Consider the number of concurrent requests for BIRT documents that the Java Factory can handle when configuring the buffer size. The Factory handles scheduled, asynchronous BIRT document generation requests one at a time.

Table 7‑6 lists the property name that appears in Configuration Console with the corresponding parameter names in acmetadescription.xml, indicating the default setting, range, and when a property change takes effect.

The administrator can configure how long the Factory keeps BIRT designs in the cache by setting a time-out value. When the time expires, the Factory clears the design from the cache. While a design remains in the cache, users who request the design share the cached file. iHub checks permissions of users to access the design. A cached design has a lifetime equal to the time-out value. Increasing the time-out value keeps designs in cache longer. The higher the time-out value, the more likely users are to access a stale design. The lower the time-out value, the sooner the Factory clears the cache.

The administrator can also configure the capacity of the cache by setting the maximum number of entries allowed in the cache. When the cache reaches capacity, the Factory stops caching designs.

Table 7‑7 lists the property names that appear in Configuration Console with the corresponding parameter names in acmetadescription.xml, indicating default settings and when a property change takes effect.

By default, iHub caches a BIRT document, including access privileges. Caching benefits users who access the document concurrently. Users who request access to the same document share the cached document if they have the required privileges. Performance can improve because iHub does not have to repeatedly load the document. Generally, the fewer number of documents iHub needs to load, the better the response time. iHub caches BIRT documents in the BIRT document in-memory archive cache. To access the cache, iHub creates a handle. If you enable the BIRT document cache, iHub caches this handle in the BIRT document cache. If you do not enable the BIRT document cache, iHub creates a new handle every time a user chooses to view a document. Enabling the BIRT document cache results in a faster response time but uses more memory, because iHub maintains the BIRT document cache in memory.

Table 7‑8 lists the property name that appears in Configuration Console with the corresponding parameter names in acmetadescription.xml, indicating the default setting and when a property change takes effect.