I have worked with Druid and ClickHouse extensively in the past year. I do think rebalancing is a weak point for ClickHouse, although for our use case that wou

I have worked with Druid and ClickHouse extensively in the past year. I do think rebalancing is a weak point for ClickHouse, although for our use case that would not be so much of an issue, and it feels like it is on the roadmap for ClickHouse this year, but we will see. And if you are on Kubernetes, some of that headache may be handled for you with the ClickHouse Kubernetes operator. I will say, that Druid indexing comes at a heavy cost in hardware for ingestion. We find ClickHouse can easily ingest at least 3x the rate of Druid on the same hardware, and since Druid is asymmetric in design, you then have to get even more hardware to handle the queries. Even with the vectorized aggregation, ClickHouse is beating Druid for full table scans at least, especially high cardinality data. But the vectorized aggregation has some restrictions to get on the fast paths, so that may improve. as those are removed. Overall, I find ClickHouse much easier to work with and manage compared to Druid. ymmv