[client-v2] `DB::Exception: <Unreadable error message>` while error returned from Cloud instance

[chernser]

Description

Exception doesn't contain message from a server: Code: 164. DB::Exception: <Unreadable error message> (transport error: 500)

Log

2025-06-10 19:16:01.278 - com.clickhouse.client.internal.apache.hc.client5.http.impl.classic.MainClientExec: ex-0000000007 connection can be kept alive for 10 SECONDS
2025-06-10 19:16:01.279 - com.clickhouse.client.api.Client: Trying to read error message: bytes available 0 
2025-06-10 19:16:01.279 - com.clickhouse.client.internal.apache.hc.client5.http.impl.classic.InternalHttpClient: InternalConnectionEndpoint-3c6022b releasing valid endpoint
2025-06-10 19:16:01.279 - com.clickhouse.client.internal.apache.hc.client5.http.impl.io.BasicHttpClientConnectionManager: ep-0000000002 Connection can be kept alive for 10 SECONDS
2025-06-10 19:16:01.279 - com.clickhouse.client.api.Client: read nothing
2025-06-10 19:16:01.279 - com.clickhouse.client.api.Client: message is empty
2025-06-10 19:16:01.281 - com.clickhouse.jdbc.internal.ExceptionUtils: Exception Message: null, Debug message: null
2025-06-10 19:16:01.372 - SQL Error [22000]: Code: 164. DB::Exception: <Unreadable error message> (transport error: 500)
org.jkiss.dbeaver.model.sql.DBSQLException: SQL Error [22000]: Code: 164. DB::Exception: <Unreadable error message> (transport error: 500)

Pay attention to the

2025-06-10 19:16:01.279 - com.clickhouse.client.internal.apache.hc.client5.http.impl.classic.InternalHttpClient: InternalConnectionEndpoint-3c6022b releasing valid endpoint

It means that response doesn't contain any body. This handled in org.apache.hc.client5.http.impl.classic.MainClientExec#execute :

// check for entity, release connection if possible
final HttpEntity entity = response.getEntity();
if (entity == null || !entity.isStreaming()) {
    // connection not needed and (assumed to be) in re-usable state
    execRuntime.releaseEndpoint();
    return new CloseableHttpResponse(response, null);
}
return new CloseableHttpResponse(response, execRuntime);

Environment

• Client version: 0.8.6
• [X] Cloud

[mshustov]

@chernser Are you able to reproduce the problem with a local or Cloud instance? are you able to reproduce with curl?

[chernser]

@mshustov I was able to reproduce with cloud instance only. I have not tried curl but in the debug mode I see that no response is coming.

[mshustov]

@chernser caused by https://github.com/ClickHouse/clickhouse-java/issues/2287?

[WenLiXue]

I encountered the same issue: I can't connect using the ClickHouse driver, but it works successfully with the legacy version. Besides, I originally intended to use DataGrip for the connection. Have you resolved this problem? my ClickHouse version is 21.7.4.18.

[chernser]

Good day, @WenLiXue ! This should be resolved in 0.9.3 and 0.9.4.

Please verify and if fails - please create an issue with how to reproduce.

Thanks!

[WenLiXue]

Hi there!

Thank you for your quick response! I’d like to confirm: could you clarify which software/tool version you’re referring to (0.9.3 and 0.9.4)? Is it the ClickHouse driver version for DataGrip or another related component?

Also, I’m still facing an issue when connecting via clickhouse-client on port 8123. Here are the details:

• My ClickHouse server and client versions are both 21.7.4.18 (official build).
• Command used: clickhouse-client -h 127.0.0.1 --port 8123 -u xxxx --password xxxx
• Error message: Code: 209. DB::NetException: Timeout exceeded while reading from socket (127.0.0.1:8123)

Notably, I can connect successfully with the legacy driver in DataGrip, but the standard ClickHouse driver and direct clickhouse-client connection on port 8123 both fail. Could this timeout issue be related to the version you mentioned?

Looking forward to your guidance! Thanks again!

[chernser]

@WenLiXue I did mean a JDBC driver version.

Timeout should not be so critical here. I think there is something else. Please create an issue so we can investigate.

Thanks!

[GuillaumePressiat]

I can confirm that the error message issue we encountered with version 0.9.2 jdbc driver (on dBeaver 25.2) has been resolved in version 0.9.4.