Common issues

You may be experiencing one of the issues below.

Production-optimized QuestDB configuration

If you can’t initially see your data through a select SQL query straight away, this is normal: by default the database will only commit data it receives though the line protocol periodically to maximize throughput.

For dev/testing you may want to tune the following database configuration parameters as so:

# server.conf

The default QuestDB configuration is more applicable for a production environment.

For these and more configuration parameters refer to database configuration documentation.

Infrequent Flushing

You may not see data appear in a timely manner because you’re not calling questdb.ingress.Sender.flush() often enough.

The questdb.ingress.Sender class only provides auto-flushing based on a buffer size and not on a timer.

Inspecting and debugging errors

Both the questdb.ingress.Sender and questdb.ingress.Buffer types support __len__ and __str__ methods to inspect the buffer that is about to be flushed.

Note that the ILP protocol does not send errors back to the client.

On error, the QuestDB server will disconnect and any error messages will be present in the server logs.

Asking for help

The best way to get help is through Slack.