Cannot View JSON/Object('json') Log Data from ClickHouse Table in Grafana #1420
Description
What happened:
We are storing logs in ClickHouse using the experimental Object('json') (JSON) column type, with each row containing structured log data. While queries using count(*) on the table show the correct number of rows, querying or visualizing the actual log data in Grafana (using the official ClickHouse plugin) either displays blank/empty results or returns (0) for each row.
What We Tried:
Using queries like SELECT CAST(log_data AS String) FROM default.keycloak_logs LIMIT 10; results in empty rows or zeros, even when the count indicates >1 million rows exist.
Trying both dot notation (log_data.Timestamp) and bracket notation (log_data['Timestamp']) for extracting fields from the log_data JSON/Object column. Both approaches result in errors.
The log rows are present, and data can be extracted (with some difficulty) through the ClickHouse CLI or by specific JSON functions, but not through Grafana.
Background:
Our logs are ingested via Vector as JSON documents into a table with this schema:
sql
CREATE TABLE IF NOT EXISTS default.keycloak_logs (
log_data JSON
) ENGINE = MergeTree()
ORDER BY tuple();
All log fields are inside the log_data column, which uses the experimental JSON/Object type.
What you expected to happen:
To view the actual log data (either as JSON or as extracted fields) in Grafana Table/Logs panels, with support for querying/extracting values within the JSON/Object column.
Guidance for correct query syntax or plugin configuration to access Object('json')/JSON columns, or information on when full support is expected.
How to reproduce it (as minimally and precisely as possible):
Screenshots
Anything else we need to know?:
Environment:
- Grafana version: 11.0.0
- Plugin version: 4.11.0
- OS Grafana is installed on: Linux
- User OS & Browser:
- Others: