The FHS says that /usr has “read-only user data” which “Should be shareable
The directory /usr/share/jitsi-videobridge in version 2.1-273-g072dd44b-1 of
your jitsi-videobridge2 package is writable by user jvb and the directory /
usr/share/jitsi-videobridge/.cache/ is frequently written by that user. I
think that /usr/share/jitsi-videobridge/.cache/ belongs under /var/cache, you
could have a symlink in /usr/share/jitsi-videobridge/.cache pointing to /var/
cache/jitsi-videobridge if needed.