Review number of fractal-server API calls

[tcompa]

If while browsing a zarr multiscale we need to open N chunk files, how many calls are made to the current-user endpoint?
We should make sure that this remains under control.

[tcompa]

TO DO: let's rechunk the original testing zarr, so that it has a lot of small chunks.

[tcompa]

TO DO: let's rechunk the original testing zarr, so that it has a lot of small chunks.

Ref #10

[zonia3000]

I've added the cache-manager package to cache the result of current user calls. We are using just it's core (in-memory implementation).

The tests using the rechunked zarr with a lot of chunks showed a visible improvements. It also appears that Node 20 is always faster than Node 16.

Node 20 (vizarr loading 818 requests):

• with cache: 4.06s
• without cache: 5.66s

Node 16 (vizarr loading 818 requests):

• with cache: 6.54s
• without cache: 7.42s

Cache expiration time can be configured using the environment variable CACHE_EXPIRATION_TIME. The default value is 60 seconds.

[tcompa]

Great!

Could you also specify what do these times refer to? Is it something like loading the first vizarr view?

[zonia3000]

Yes, I'm loading this page, using the rechunked test zarr:

[tcompa]

I tested this myself as well, as part of #15, and I confirm it works as expected.
I loaded the many-chunks version of our testing data, and kept browsing it for a while. And fractal-server logs show that the API was only called once per minute

2024-07-23 13:28:23,783 - uvicorn.access - INFO - 127.0.0.1:33950 - "GET /auth/current-user/ HTTP/1.1" 200
2024-07-23 13:29:26,782 - uvicorn.access - INFO - 127.0.0.1:40774 - "GET /auth/current-user/ HTTP/1.1" 200
2024-07-23 13:30:26,830 - uvicorn.access - INFO - 127.0.0.1:50488 - "GET /auth/current-user/ HTTP/1.1" 200