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Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
Open source
Tag search
An issue occurs while searching for traces in Grafana Explore. The Service Name and Span Name drop down lists are empty, and there is a No options found
message.
HTTP requests to Tempo query frontend endpoint at /api/search/tag/service.name/values
would respond with an empty set.
Root cause
The introduction of a cap on the size of tags causes this issue.
Configuration parameter max_bytes_per_tag_values_query
causes the return of an empty result
when a query exceeds the configured value.
Solutions
There are two main solutions to this issue:
- Reduce the cardinality of tags pushed to Tempo. Reducing the number of unique tag values will reduce the size returned by a tag search query.
- Increase the
max_bytes_per_tag_values_query
parameter in the overrides block of your Tempo configuration to a value as high as 50MB.
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