Connection Issue: ClickHouse Go Driver vs. CLI

[theboringhumane]

Observed

1. Connecting with the clickhouse-go driver to ClickHouse Cloud (Azure & GCP) fails with a connection reset by peer error.
2. Self-hosted ClickHouse deployments work perfectly fine with the Go driver.
3. The official ClickHouse CLI (clickhouse-client) is able to connect to both cloud and self-hosted environments without any issues.

Expected behaviour

• The Go driver should connect successfully to ClickHouse Cloud deployments (similar to both self-hosted and the CLI client).

Code example

package main

import (
	"database/sql"
	"fmt"
	"log"

	_ "github.com/ClickHouse/clickhouse-go/v2"
)

func main() {
	connStr := "clickhouse://<user>:<password>@<cloud-host>:9440/<database>?secure=true"
	db, err := sql.Open("clickhouse", connStr)
	if err != nil {
		log.Fatalf("sql.Open error: %v", err)
	}
	defer db.Close()

	if err := db.Ping(); err != nil {
		log.Fatalf("Ping error: %v", err)
	}

	var one int
	if err := db.QueryRow("SELECT 1").Scan(&one); err != nil {
		log.Fatalf("QueryRow error: %v", err)
	}
	fmt.Println("Result:", one)
}

Error log

[clickhouse][4.152.12.124:9440][id=4][handshake] ->  0.0.0
[clickhouse-std][opener] [connect] error connecting to xxxxxx.eastus2.azure.clickhouse.cloud:9440 on connection 4: read: read tcp xxx.168.68.110:53028->x.xxx.xx.124:9440: read: connection reset by peer

Details

Environment

• [x] clickhouse-go version: v2.40.3
• [x] Interface: ClickHouse API / database/sql compatible driver: database/sql
• [x] Go version: 1.24.0
• [x] Operating system: MacOS/Linux
• [ ] ClickHouse version:
• [x] Is it a ClickHouse Cloud? Yes (Azure & GCP)
• [ ] ClickHouse Server non-default settings, if any:
• [ ] CREATE TABLE statements for tables involved:
• [ ] Sample data for all these tables, use [clickhouse-obfuscator](https://github.com/ClickHouse/ClickHouse/blob/master/programs/obfuscator/Obfuscator.cpp#L42-L80) if necessary

[kavirajk]

Hi @theboringhumane thanks for the issue. I'm failing to reproduce the issue with the example code you attached on "running" cloud service.

Tried it in Azure (east-us2 region) and able to connect by just changing the connection string in your example (printing the Result: 1 just fine).

Also I'm able to reproduce the exact error when connecting to service that is stopped (or "idle").

go run main.go
2025/09/29 11:12:04 Ping error: read tcp 192.168.2.20:37948->x.x.x.x:9440: read: connection reset by peer
exit status 1

Can you make sure if your service is up and running?