Copr-cache metrics on TiDB have no data

[jackysp]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. make some queries to hit the cache.

2. checkout the metrics on Grafana.

2. What did you expect to see? (Required)

Some hit/miss data.

3. What did you see instead (Required)

No data as above.

4. What is your TiDB version? (Required)

v5.0.1

[ti-srebot]

Please edit this comment or add a new comment to complete the following information

Bug

1. Root Cause Analysis (RCA) (optional)

Wrong metrics formula.

2. Symptom (optional)

No data.

3. All Trigger Conditions (optional)

No.

4. Workaround (optional)

No.

5. Affected versions

[v4.0.0: v5.1.0]

6. Fixed versions

master

[ti-srebot]

( component or sig(label) severity(label) AffectedVersions ) fields are empty.
The values in ( AffectedVersions ) fields are incorrect.

[tiancaiamao]

Fixed before 4.0.16 ... not sure which one exactly.