Is there a way to display the number of currently open sessions on a database in google spanner?
The limit is mentioned here:
Sessions per database per node - 10,000
I have looked through the documentation on SQL functions and gcloud spanner command line tool, but neither mentioned a way to show how many were open.

There is now a command to list active sessions:
gcloud spanner databases sessions list --instance <your-spanner-instance> --database <your-database>You can then parse this file or count the lines and figure out how many open sessions there are.