But for the life of us, we can’t figure out how to turn the behavior on, and get the traces sent. I’d have assumed it was a new 7.0 thing, but the code references supporting 5.2 through 6.2.
It’s enabled and disabled via fdbcli> profile client, which enables and disables it for all clients via state in the database. You can enable and disable it on a client-by-client basis if you set the knobs CSI_SAMPLING_PROBABILITY and CSI_SIZE_LIMIT on the client.
fdbcli> profile client set 0.01 100MB profiles 1% of transactions and maintains 100MB worth of history in the database.