ClickHouse
increased memory usage in native v2 client
Issue description
Our system of ClickHouse inserters have been using the native v2.2.0 client with success for several weeks. After upgrading to v2.4.3 a few days ago, we noticed that the memory and CPU usage increased markedly. Memory usage was roughly 7-10x more, and CPU usage was 6-9x more on our k8 pods.
Example code
Our inserters collect in memory ~250k messages, morph them each into ClickHouse row batches and call client.WriteBatch() after checking to see if a lock table doesn't have any rows. The columns contain array(string), array(uint8) uint8, and string types. And some of the array(string) average about 500 elements.
Error log
didn't see any insert error logs
Configuration
OS:
pod images are built using golang:1.19
I think this is the OS:
cat /etc/*-release
...
Debian GNU/Linux 11
...
Interface: E.g. native, database/sql
native
Driver version: v.2.4.3
Go version: run go version in your console
1.19.4
ClickHouse Server version: 22.8.5.29
Doing quick benchmarks I can confirm much more CPU & memory (x4) appetite for a test that does ingestion as you do. This definitely requires more attention.
@jkaflik can you please share your benchmark so I can investigate this issue too?
@ernado benchmark I used to get mentioned results is: https://github.com/ClickHouse/clickhouse-go/blob/b7fbe1f4b3c36e43d135a02e340884cdc2f8a4c8/benchmark/v2/write-native/main.go
