Thanks for stopping in. I've been seeing a lot of InfluxDB 3.0 content in the past few days. It would be helpful for me at least to see more comparison between 2.x and 3.0? Not sure if there is a changelog or list of things that were added/deleted/are now incompatible between versions. Cheers
The differences in 2.x and 3.x are quite significant. The 3.0 database was a ground up rewrite in a new language (v1 and v2 were in Go, v3 is in Rust).
InfluxDB v2 was all about the Flux language and a much broader set of API capabilities along with an integrated UI.
For 3.0 we focused on the core database technology. We were able to bring the 1.x APIs forward, which means 3.0 supports both InfluxQL and SQL natively. We were only able to add Flux support through a separate process and a lower level gRPC API that the two use to communicate.
The underlying database architecture is also completely different. v1 and v2 are essentially an inverted index paired with a time series store. v3 organizes data into larger Parquet files and pairs that with a columnar query engine (Apache DataFusion) to execute fast queries against it.
Me or someone on our team should probably write a detailed post about the underlying database architecture to highlight the differences between the versions.
We built 3.0 mainly to accomplish some things that we were unable to deliver in v1 or v2:
* Unlimited cardinality
* Tiered data storage
* Fast analytic queries
* SQL compatability
* Bulk data import and export (coming soon to v3)
Then there are the systems architecture changes we made highlighted in this blog post. v1 InfluxDB was a monolithic database that had all these components in one. The v3 design allows us to scale ingest, query, and compaction separately, which is something that kept coming up in larger scale use cases.
