Adjusting worker threads to improve thumbnail generation performance

Content Platform Engine uses worker threads to generate thumbnails. The worker threads delegates rendering of images to the external process ibmfnthb. Each ibmfnthb process integrates with Oracle® Outside in Image Export and uses up processor resources and some amount of memory. The ibmfnthb processes are external to the Content Platform Engine Java™ Virtual Machine. As a result, the ibmfnthb processes use memory in addition to the memory that you allocated to the Content Platform Engine JVM. The number of processor cycles and the amount of memory that each ibmfnthb process uses depends on the size and complexity of the documents rendered. Larger and more complex documents require more processor resources and more memory.

On UNIX system-based servers, such as AIX, HP-UX, Linux, Linux on System z, and Solaris, the Oracle Outside In Image Export libraries use an X server to render the thumbnail images for non-raster or vector graphics format document types such as Office documents, PDF files, and CAD drawings. The libraries rely on the presence of the X libraries Xm, Xt, and X11 on the UNIX system-based server. The X server can be local or remote to the Content Platform Engine server, and there can be more than one X server that the Content Platform Engine configuration is configured to point to. In generating thumbnail images for raster (bitmapped) format files such as GIF, JPEG, TIFF, and BMP on UNIX system-based servers, Outside In Image Export does not require an X server. When the X server is remote, the Content Platform Engine server is affected less by the thumbnail rendering, but a local X server gives better throughput than a remote X server.

On Microsoft Windows servers, Outside In Image Export does not need an X server. Outside In Image Export uses the built-in Windows Graphics Device Interface (GDI) to render the first page of documents of all formats to images.

Use your operating system tools to monitor the amount of processor resources that are used by the thumbnail generation processes (ibmfnthb) during peak usage. Use the administration console to set the number of worker threads so that processor usage is not excessive. Using more worker threads than processor cores is not as effective because thumbnail generation is processor-intensive.