The original TSM engine is still used by InfluxDB v2 OSS. The InfluxDB Cloud platform uses a variation of TSM that's tailored for a distributed SaaS rather tha

The original TSM engine is still used by InfluxDB v2 OSS. The InfluxDB Cloud platform uses a variation of TSM that's tailored for a distributed SaaS rather than stand-alone nodes (this was originally intended to be used in InfluxDB v2 OSS as well, but alpha-testing showed that the old engine performed better there so it ultimately was reverted for the beta release). So IOx is really the first major new storage engine in InfluxDB.