Dash client-side callback vs dcc.store

Question

I have dash app connected to an AWS RDS. I have a live-updated graph that triggers a callback with a n_interval of 5min to query the database and do some expensive formatting. I store the transformed data (~500 data points) in a dcc.store from which another 6 graphs and a datatable utilize this data (no further processing required. My question is: To further improve the efficiency of the dashboard should I utilize client-side callbacks instead of dcc.store? Since from what I've read the client-side only utilizes the client browser and doesn't need to communicate back to the dash server on callback? Thank you.( I'm secretly hoping it makes little difference as I don't want to learn javascript)

Answer 1

The answer depends a lot on your architecture, how complex are the graphs and how many server side callbacks are currently used.

You have already mentioned the main advantage of clientside callbacks: since the data is on the clientside, it saves some time and network by updating the components directly on the client. The major inconvenience is that those are synchronous calculations and will block the app main thread (dash does not support promises and asynchronous for now), which Can lead to a bad UX if these functions take too much time.

For very simple plots and table, I can guarantee that there is a significant improvement in using clientside callbacks, especially because it avoids the Plotly API that can be much slower than just defining a JSON object with traces and layout.