The system is not fully utilized when importing data from clickhouse-client. #42372
Description
Describe the situation
See #42363
CREATE TABLE passwords
(
`hash` FixedString(20) CODEC(ZSTD(6)),
`count` UInt32 CODEC(ZSTD(6))
)
ENGINE = MergeTree
ORDER BY hash
clickhouse-client --progress --query "INSERT INTO passwords WITH splitByChar(':', line) AS columns SELECT unhex(columns[1]), replaceOne(columns[2], '\r', '') FROM input('line String') FORMAT LineAsString" < pwned-passwords-sha1-ordered-by-hash-v8.txt
clickhouse-client is using only 20..30% CPU and clickhouse-server is using 300..400% CPU, but I have a much higher number of CPUs.
To solve this problem, clickhouse-server can respect max_insert_threads by accepting more blocks of data from the client while processing previous blocks of data.