Summary of the Issue
The customer has reported that with APS 1.7.0 where we ship aspose-pdf-10.3.0.jar, when the system is somewhat under-resourced and the files are located in NFS mount, when attachments are added and deleted from tasks, the following messages are logged in the system and eventually leading to the system shutdown where the customer has to restart APS.
Customer has identified that upgrading the aspose-pdf jar to the newer version, namely 11.5.0, alleviated the issue.
It appears that when the transformation has been triggered for large attachments (10 MB) and aspose-pdf.jar started the transformation thread, and when the target file is deleted if the system is slow, the transformation seems to continue even though the target file does not exist any longer, hence leading to blocked threads, which eventually eats up the system resources.
The 3rd party has already identified this issue and has provided an update in version 11.5.0 and based on this, please update our jar to match the newly updated version that contains the fix.
Reference Link from Aspose Internal JIRA
I was not able to reproduce this issue on my local box with NFS mount. Customer also has reported that the reproduction requires a significant slow system, but was not able to provide the particulars of the system settings.