Forum Discussion

dbeavon3's avatar
dbeavon3
Memorable Member
10 months ago
Solved

Synapse Notebook UI thinks cell is running. Notebook won't proceed.

Curious about the notebook ui.  Sometimes I use the command "run this cell and all below".   That is predominently a UI operation that will continue generating user input to advance from one cell t...
data engineering
  • v-echaithra's avatar
    v-echaithra
    10 months ago

    Hi dbeavon3 ,

    Manual Recovery

    This usually works if the session hasn't fully died.
    Click "Stop". This tries to cancel the current cell.
    Wait 5-10 seconds to see if the cell resets to idle.

    If it doesn’t work:
    Refresh the browser tab (press F5).
    Synapse will try to reconnect to the Spark session.
    Often the notebook will recognize that the session is active and re-sync.
    If successful, you can now continue executing from any cell.

    Kernel Restart

    If refreshing doesn't help:
    Use the "Manage Sessions".
    Click "Restart session" or "Disconnect & Clear State".
    This will kill the Spark session and reset all state.
    Re-run cells from the top (or your desired point).

    As you mentioned this: "I'm guessing I need to open a new browser tab and pray that my session gets reconnected..." You're not wrong. Opening a new browser tab to the same notebook can sometimes:
    Reconnect to the live session
    Force UI state to reinitialize

    But if the old tab’s UI thread is stuck, the Spark driver may still be considered “active” and resist reconnection. Don’t hit “Run All Below” again while stuck, it just queues new UI commands to an already desynced frontend. Avoid spamming “Stop”, it can sometimes hang even further.

    Hope this helps.
    Thank you

v-echaithra's avatar
v-echaithra
Community Support
10 months ago

Hi dbeavon3 ,

Manual Recovery

This usually works if the session hasn't fully died.
Click "Stop". This tries to cancel the current cell.
Wait 5-10 seconds to see if the cell resets to idle.

If it doesn’t work:
Refresh the browser tab (press F5).
Synapse will try to reconnect to the Spark session.
Often the notebook will recognize that the session is active and re-sync.
If successful, you can now continue executing from any cell.

Kernel Restart

If refreshing doesn't help:
Use the "Manage Sessions".
Click "Restart session" or "Disconnect & Clear State".
This will kill the Spark session and reset all state.
Re-run cells from the top (or your desired point).

As you mentioned this: "I'm guessing I need to open a new browser tab and pray that my session gets reconnected..." You're not wrong. Opening a new browser tab to the same notebook can sometimes:
Reconnect to the live session
Force UI state to reinitialize

But if the old tab’s UI thread is stuck, the Spark driver may still be considered “active” and resist reconnection. Don’t hit “Run All Below” again while stuck, it just queues new UI commands to an already desynced frontend. Avoid spamming “Stop”, it can sometimes hang even further.

Hope this helps.
Thank you

dbeavon3's avatar
dbeavon3
Memorable Member
10 months ago

Thanks for this.  Given the elaborate recovery recipes you shared, I see that the experience is not specific to me or my solution.  If any other IDE (say Visual Studio, or Intellij, or Eclipse, or even VS code) behaved like this, developers would quickly jump ship.  I'm guessing that the majority of Fabric developers must be a lot more patient than I am.