OpenText
Documentum comes with a number of default settings that are not appropriate for
most projects and can even cause problems when applied to a production system
unchanged. One of those settings concerns thumbnails.
Documentum
xCP is a great tool for creating Case Management applications using no code. It
includes a viewer that can show your documents alongside their metadata and
other relevant process information. Great stuff! The way that this viewer shows
your documents can have some consequences however.
The xCP
viewer can show documents of any file format by converting the pages of the
document into images called thumbnails and then displaying the thumbnails in
your browser. There are large thumbnails that are displayed in the main viewer
window. There are also small thumbnails that are shown in the viewer’s page
navigation bar on the left. All these thumbnail images that are generated are
stored in Documentum with the document as renditions. Once the thumbnails have
been generated, the next time you view the document the viewer only has to
retrieve them.
An xCP application
displaying a document
Now here is
the downside that can cause problems for your system. Documentum has a default
setting that will enable automatic thumbnail generation for all documents in
your system. Though the idea sounds nice at first, it means that a number of
extra renditions will be added to every version of every document in you
Documentum system, even if no one is going to look at the document using the
xCP Viewer. All these renditions take up extra disk space. A LOT of extra disk
space. The generated thumbnails can take up more space than the original
content files, so your space requirement for content files will be 2x to 3x as
much as needed for the original content. If you have millions of documents with
terabytes of content files, you will need a serious budget increase just to
store all the thumbnails.
Fortunately
there are several ways to improve this situation. To start with, you can
disable the default configuration and enable automatic thumbnail generation
just for the document types and content types that will be displayed in the xCP
application. This will reduce the number of useless thumbnails that are
generated.
You can also
turn off the automatic thumbnail generation altogether. In this case the xCP
Viewer will generate the thumbnails it needs when it displays a document. This will
take a second or so, but will save enormously on the storage needed for the
thumbnails. The only downside is that the page navigation on the left side of
the viewer does not work in this configuration. the xCP Viewer does not
generate the small thumbnails needed for the page navigation. It only generates
the main thumbnails.
At Informed
Consulting we created a solution that improves on this in 2 ways:
-
A
small xCP custom module that generates the small thumbnails for the xCP viewer
-
A
custom job that deletes old thumbnails that are no longer needed
With these
improvements we’ve cut the diskspace needed for thumbnails by 95% without
losing any functionality in the xCP Viewer.
If you’re
struggling with a Documentum project, contact us, we’ll be glad to help.