I know nothing about InfluxDB or VeraFlux, but there are many articles on InfluxDB memory hunger. These may be relevant, search for others:
(see discussion under “InfluxDB Advantages” section in this article)
I also note you have a Java process running. Java’s runtime allocates but never frees memory from the system. It will allocate memory from its configured min/start (
-Xms) to its configured max (
-Xmx) linearly; it will never return unused memory to the system. You may need to periodically restart the java process to reduce overall system memory use (ideally, of course, you would find a happy setting for max that works for your other system process and the total amount of system RAM, so that java hitting its limit doesn’t cause paging (swap) or system failure).
Increasing your swap size is likely only going to slow your system down and cause excess wear on the drive.