Very slow response with large data

[paulotex]

The front end becomes unresponsive (each action takes tens of secs) when loading large data. For example, using this URI:
imas:hdf5?path=/work/imas/shared/imasdb/ITER/3/131047/20
Then select distributions/distribution/ggd/expansion/grid_subset/values

There are 3.5 million values there (54 x 640 x 100).

Some parts of the UI work ok, but others do not or take tens of seconds to respond..

[jwasikpsnc]

FYI: The response size here is ~100MB, and it takes backend ~1s to return it

curl -X 'GET'   'http://localhost:40443/data/plot_data?uri=imas%3Ahdf5%3Fpath%3D%2Fwork%2Fimas%2Fshared%2Fimasdb%2FITER%2F3%2F131047%2F20%23distributions%2Fdistribution%5B%3A%5D%2Fggd%5B%3A%5D%2Fexpansion%5B%3A%5D%2Fgrid_subset%5B%3A%5D%2Fvalues&savgol_smoothing_mode=interp&downsampled_size=1000'   -H 'accept: application/json' -o /dev/null

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 97.1M  100 97.1M    0     0  94.2M      0  0:00:01  0:00:01 --:--:-- 94.3M