Hey Iceberg Community, Scan metrics support was introduced in 1.1.0 that is pretty nice to collect some per-query stats like 'total planning duration' and such. However, I haven't found a way to get process level metrics at the moment. The particular thing I wanted to achieve is that there was a Manifest file content cache <https://github.com/apache/iceberg/pull/4518> introduced recently where the stats are logged, but aren't exposed through the API.
Such an API could be used to expose stats for various kinds of caches (e.g. number of hits and misses), we could count the number of specific API calls (like planFiles()) and I guess many more other useful stuff. With this mail I'd like to initiate a discussion around this topic. If the community is open for such a change I could start working on an initial solution that would expose the Manifest file content cache stats but could be extended later on with more metrics. Cheers, Gabor
