v.23.8Improvement
Change Default max_concurrent_queries from 100 to 1000
Change the default of max_concurrent_queries from 100 to 1000. It's ok to have many concurrent queries if they are not heavy, and mostly waiting for the network. Note: don't confuse concurrent queries and QPS: for example, ClickHouse server can do tens of thousands of QPS with less than 100 concurrent queries. #53285 (Alexey Milovidov).Why it matters
The change addresses the limitation on the number of concurrent queries by raising the default limit, which benefits workloads with many lightweight or mostly network-waiting queries. This allows ClickHouse to handle higher concurrency without being bottlenecked by the default setting, improving overall query throughput for users operating with numerous simultaneous queries.How to use it
This feature is enabled by default in the new version by setting themax_concurrent_queries parameter to 1000. Users can configure this setting in the server configuration file or at runtime if adjustments are needed.