(Tom here; I started the Cortex project on which Mimir is based and lead the team behind Mimir)
Thanos is an awesome piece of software, and the Thanos team have done a great job building an vibrant community. I'm a big fan - so much so we used Thanos' storage in Cortex.
Mimir builds on this and makes it even more scalable and performance (with a sharded compactor and query engine). Mimir is multitenant from day 1, whereas this is a relatively new thing in Thanos I believe. Mimir has a slightly different deployment model to Thanos, but honestly even this is converging.
Generally: choosing Thanos is always going to be a good choice, but IMO choosing Mimir is an even better one :-p
Thanos is an awesome piece of software, and the Thanos team have done a great job building an vibrant community. I'm a big fan - so much so we used Thanos' storage in Cortex.
Mimir builds on this and makes it even more scalable and performance (with a sharded compactor and query engine). Mimir is multitenant from day 1, whereas this is a relatively new thing in Thanos I believe. Mimir has a slightly different deployment model to Thanos, but honestly even this is converging.
Generally: choosing Thanos is always going to be a good choice, but IMO choosing Mimir is an even better one :-p