Signal --prune complete

[dapplion]

Rationale

For automated managers of Geth nodes (i.e. DAppNode dappnode/DNP_DAPPMANAGER#915) it would be necessary to know reliably that --prune has completed (either successfully or not), in order to restart Geth without --prune flag. To my knowledge the only signal that pruning is done is a log to stdout.

Implementation

Touch a flag file when prune is complete if some flag is set, i.e. --prune-flag-file. Otherwise if the team can assure that the printed log to stdout is reliable enough and won't ever change without a breaking change notice that should work too but it's a bit more ugly.

Let me know if that makes sense or what you think is a better strategy

[rjl493456442]

Do you mean geth snapshot --prune? If so it's will be deprecated in the following months.
New state scheme will be applied into Geth so that pruning is always enabled by default.

[dapplion]

Do you mean geth snapshot --prune? If so it's will be deprecated in the following months. New state scheme will be applied into Geth so that pruning is always enabled by default.

Any issue or tracker I can follow for this? What would you suggest as best solution short term while that's in development?

[yorickdowne]

Any issue or tracker I can follow for this? What would you suggest as best solution short term while that's in development?

#23427 looks relevant as does #23733

[holiman]

We don't have --prune, we only have geth snapshot --prune-state

[holiman]

Also, once it's done, the process will exit. Why is that not sufficient? I mean, you could always do
geth snapshot --prune-state; touch pruning_done && notify "done now" more or less

[dapplion]

Also, once it's done, the process will exit. Why is that not sufficient? I mean, you could always do geth snapshot --prune-state; touch pruning_done && notify "done now" more or less

That's sufficient yes, sorry I wasn't aware of this fact.