These settings configure the ClickHouse server and are autogenerated from ClickHouse source.
max_io_thread_pool_free_size
If the number of idle threads in the IO Thread pool exceeds max_io_thread_pool_free_size, ClickHouse will release resources occupied by idling threads and decrease the pool size. Threads can be created again if necessary.
max_io_thread_pool_size
ClickHouse uses threads from the IO Thread pool to do some IO operations (e.g. to interact with S3). max_io_thread_pool_size limits the maximum number of threads in the pool. Last modified on July 23, 2026
