Of course, as it is continually starting and crashing, most of the time it is just starting up, reading in the database config and so on, so you may not ever see the memory utilisation high.
This obviously isn't a node-red issue, I suspect that your database is just too big. Googling for
influxd-systemd-start.sh runtime: out of memory: cannot allocate block
may be helpful. I suggest stopping everything you can on the system in order to free up as much memory as possible. Are you running a browser or GUI on the device? If so shut those down and connect using SSH. Obviously shut down node-red so that it is not trying to add to the db. If you can get influxd to start successfully then you can delete some of the data. Otherwise I suspect you may not be able to recover the data, unless you can fit more RAM.
Possibly posting in an influxdb forum may get you somewhere.
If you do find a solution then post back here in case anyone else has the same problem.
A thought though, does influxd have access to the full memory in your system?
