About TEXTML Server cache processes

This section describes how the cache is used during read, write and commit transactions.

Figure 1 shows how TEXTML Server stores and handles data.

Figure: TEXTML Server docbase transactions

Each time a document is updated, TEXTML Server fetches pages from the disk and eventually writes them to the cache. This write transaction is added to the list of logger records. When the transaction finishes, the logger cache flushes its contents to the disk (commit transaction).

The cache memory is flushed to disk separately in order to optimize the speed with which docbase files are written to disk, and to speed up the transactions. As the flush task progresses, it triggers the removal of outdated logger records from the disk.

If there is a lot of write activity, two things will happen in TEXTML Server:

1. The cache memory will increase to accommodate the extra pages.
2. The logger records in the docbase will accumulate on disk.

As the write activity slows down, the load on system memory is reduced. However, if write activity is intense over a very long period of time, the server will temporarily slow down its activities so the flush task can send pages to disk. The <cache> parameters in the <DocumentBaseProperties> element control this process.