Cannot create object with large plotly chart from web interface

[theo-martel]

Trying to create/update objects from the web interface seems to fail when the data stored in the properties is too large (more than a few hundred kilobytes ?). Doing the same thing while using the HTTP API works as expected.

I saw the following symptoms :

• When accessing the service through a nginx reverse proxy, creating/updating some objects with large plotly charts return "Request Entity Too Large. The data value transmitted exceeds the capacity limit."
• When accessing the service directly from localhost, Firefox would give the error "The connection was reset" on creating/updating some objects with large plotly charts

I tried to change nginx's configuration (client_max_body_size = 100M;), as well as Flask's (MAX_CONTENT_LENGTH to a few billions), with no success.

I am not seeing any error in SampleDB docker logs.

Minimal example :
Try to create an object with the following two properties :

• name : something
• chart : a plotly chart with the following data data.txt. This chart was crafted to be a small as possible while still triggering the error, as removing 200 points is enough for the object creation to work on my instance

[FlorianRhiem]

Hey @theo-martel, I've tracked down the issue to a change in werkzeug 3.1.0, specifically it's the change discussed in this issue. The max_form_memory_size value of the werkzeug Request class (and as such the flask Request class, which is a subclass of it) defaults to 500kB, so once that is exhausted, the request is deemed too large. This default can be replaced using the MAX_FORM_MEMORY_SIZE config value in Flask, which currently cannot be set using the usual environment values for SampleDB, as it will be treated as a string. This will be fixed in the next release, so that you'll be able to set SAMPLEDB_MAX_FORM_MEMORY_SIZE then, but for now what you could do is e.g. adding a new line MAX_FORM_MEMORY_SIZE = 1000000 to sampledb/config.py.