temp files deleted while still opened under high load results in full root filesystem

[hi-ko]

using the alfresco-transform-core-aio-boot-2.4.0 the on a system having high throughput we observe deletions of tempfiles while they are still opened by the same process. This is an issue because the disk space will not be freed and it's just a question of time until the root filesystem is full.

In a running system the alfresco-transform-core-aio-boot process writes temp files e.g. to

/tmp/tomcat.8090.11347239618847497578/work/Tomcat/localhost/ROOT

checking the proc filesystem shows that the kernel keeps hundreds of files which are deleted but still opened by the alfresco-transform-core-aio-boot process:

e.g.:

ls -l --time-style="+%Y-%m-%d" /proc/$ALF_PID/fd|grep upload|grep deleted
lr-x------ 1 alfresco alfresco 64 2021-12-15 96 -> /tmp/tomcat.8090.11347239618847497578/work/Tomcat/localhost/ROOT/upload_8be27646_b262_4a90_a03f_5d4f5c53c025_01506408.tmp (deleted)

[snip]

This means the files are still kept on the filesystem until the process ends.

Only work around for now is to restart the alfresco-transform-core-aio-boot process regularily.