Is contract.on reliable for production?

[kraikov]

Hey!

Is it okay to use contract.on for event listening on production? We've implemented a mechanism to keep track which events are already processed and what's the latest processed block so we can handle failures. I was wondering if it is possible to miss an event?

We have our own node on DigitalOcean and it seems everything is working flawlessly on Ropsten.

Thanks in advance.

[ricmoo]

The contract.on just uses the normal provider.getLogs, so if you consider that ok for production, then yes. :)

Missing events is more a thing that would happen on the node side, and it depends on your failure recovery more so then anything. I generally do no see missed events for recent blocks, but if your service went down for too many blocks, when it came back up, there may have been events which were pruned. And that doesn’t mean it never happens, so depends on how important events are to correct operation.

In general I would always recommend building a caching layer for events, if they are mission critical, since you usually need them frequently and quickly.

[ricmoo]

Closing this now, but please feel free to continue discussion (I monitor closed issues) or re-open.

Thanks! :)