Local file system restrictions

Anvil Q&A
1

What are the restrictions in term of storage space, persistency, security concerns etc… from using the local file system to store temporary files.

I run a analysis script which writes a couple of png’s and pdf’s. At the end of the script all of the files are merged into a single downloadable pdf. It is much quicker for me to write the temporary files to the local file system and then access them from there. Once the script is done, all temp files are deleted. I can use the database as a temporary store, but it’s a little bit slower than storing it locally.

I’m expecting only a handful of users to access the system at a particular time.
Here are some questions:

  • How much local file space do I have to work with? (5mB, 100mB?)
  • Will a client instance access the same server file system for the duration of the session?
  • How does this change between professional and dedicated plans?
  • Anything to look out for from your experience?
2

This is not guaranteed. Even if you are running a Persistent Server instance, that instance may be shut down, and a new one started, for load-balancing (or error-recovery) purposes. The new instance might be started on a completely different physical computer.

I’m not sure how often this happens in practice – I haven’t needed Persistent Server yet – but it’s there, and probably needs to be accounted for in your design and implementation.

If you want more control over when that happens, consider using Uplink instead.