Sending large tiff files through send_file causes the callback to hang indefinitely

[matt-sd-watson]

• replace the result of pip list | grep dash below

dash                          2.18.2
dash-ag-grid                  2.3.0
dash-auth                     2.0.0
dash-bio                      1.0.2
dash-bootstrap-components     1.4.1
dash_canvas                   0.1.0
dash-core-components          2.0.0
dash_daq                      0.5.0
dash-draggable                0.1.2
dash-extensions               1.0.1
dash-google-auth              0.1.2
dash-html-components          2.0.0
dash-mantine-components       0.12.1
dash-table                    5.0.0
dash-testing-stub             0.0.2
dash_tour_component           0.0.2
dash_uploader                 0.7.0a1

• if frontend related, tell us your Browser, Version and OS

  • OS: [e.g. iOS] Linux
  • Browser [e.g. chrome, safari] Chrome
  • Version [e.g. 22] 131.0.6778.204 (64-bit)

Describe the bug

Our dash application enables users to generate multiplexed channel images and export them as tiff. The export is handled through dcc.send_file. This routinely works for files up to 100-200mb in size, but for larger tiffs such as 400-500mb, the callback gets stuck when sending the file. By checking the temp cache where the tiff is initially written, I can see that the send_file function is causing the delay, as the tiff has already been written to a temporary location.

Expected behavior

Considering that sending a 100 mb tiff through with send_file typically takes 3-4 seconds, I would expect the larger 500mb tiff to take approximately a linear amount of time proportionally to complete.