After upgrading SigNoz from 0.56.0 to 0.57.0, existing log-based value widgets on dashboards report 0, while recreating the identical widget shows correct numbers. Removing all where conditions makes the old widget work; re-adding them fixes it, which rules out the query itself.
Upgrading to SigNoz 0.57.0 broke log-based value widgets (report 0)
Root cause: stale metadata in ClickHouse. If your team ever switched from log attributes to resource attributes (e.g. for service.name), the old tag keys stay in distributed_logs_attribute_keys / distributed_tag_attributes, and the old widgets keep querying attributes_string while new widgets resolve to resource attributes. Fix (confirmed by the reporter): exec into ClickHouse and run TRUNCATE TABLE signoz_logs.logs_attribute_keys ON CLUSTER cluster and TRUNCATE TABLE signoz_logs.tag_attributes ON CLUSTER cluster. Note truncating the distributed_ variants does not delete the data. Then re-select the where conditions pointing at Type: Resource.
Source: https://github.com/SigNoz/signoz/issues/6304
Source: https://github.com/SigNoz/signoz/issues/6304