How could I trucate data after pull in Java client.

[Hello Wood]

Hi, I using Prometheus to collect Spring Boot service metrics in Java. But I found a problem that data still exsit after pull, that made the instant data is not correct. 

Like at now there has one label like 'app_version{version=a} 100', then the metrics updated, and add a new label value b, the metrics come to 'app_version{version=a} 50' and 'app_version{version=b} 50'; Then, label a no longer update, and metrics come to 'app_version{version=b} 100'.

When I pull metrics form Spring Boot service, the metrics is 'app_version{version=a} 50' and 'app_version{version=b} 100'. But expect data should be 'app_version{version=b} 100' only. 

How could I fix this issue? Thanks.

[Stuart Clark]

I think possibly you aren't using labels in the way expected.

Labels are used to "slice & dice" the data, so for example to be able to
see which specific HTTP response code was returned from a web call, etc.

What is the value of the metric app_version supposed to signify?

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Stuart Clark

[Hello Wood]

Thanks very much.

I query data from anthor metrics system and handle it to prometheus format. Like my comment, the `app_version{version=a} ` is in changing, there will generate new label value and the old label value may not used anymore. But it still in query result.

[Brian Candler]

Each combination of metric name plus set of label names and values defines a new metric (timeseries).

If you change a label, then you're creating a new metric.  Not knowing the Java API, I'd suspect that you have to explicitly delete the old metric.