Summary

When adding TIFF images with high resolution (10K - 16K) the attachment does not render a thumbnail on the page
In the case of the 16K image, the conversion processes consume all available heap memory and turning to Out Of Memory error.
In case of 2GB of heap memory the heap usage on Out of Memory event will be the following:

Steps to Reproduce

1. Get TIFF with big pixel size (i.e. Hubble’s Largest Images) or scan from one of the production scanners like Océ TC4
2. Adapt the uploading limit setting OR convert the file into grayscale to reduce the file size but keep the pixel size.
3. Add it to the page
4. Push Save button

Expected Results

The preview generated or notification occurred that's not possible to generate a preview due to bug pixel size

Actual Results

The system became irresponsive and in the log a lot of methods through an error: java.lang.OutOfMemoryError: Java heap space

Workaround

Disable the file conversions service

You may choose to disable the file conversion service to prevent any further out of memory errors.
This means that only images (excluding tif) and PDF files will appear in the preview. Users won't be able to preview or comment on other files.

To disable the file conversion service:

1. Go to Cog icon > Add-ons.
2. Locate the Confluence Document Conversion Library system add-on.
3. Disable the File Conversions (file-conversions) module.

Once disabled, Office and other files won't appear in the preview (even if they were previously uploaded), and thumbnails for existing Office and PDF files will revert back to being placeholder thumbnails (with an icon, rather than a preview of the document). You also won't be able to view any existing inline comments on the file (as the preview is disabled).