Combine multiple strings into one for calculation


We have pulsar as our messaging system and when even we create pulsar topic as say “disk_usage” we see 3 topics like " disk_usage-partition-0,disk_usage-partition-1 and disk_usage-partition-2.

Now i was trying to group sum for each of the above topic.
We have data like say:
disk_usage-partition-0 : 10
disk_usage-partition-1: 20
disk_usage-partition-2 : 30

But, in Prometheus/Grafana i want to display as disk_usage: 60.

Can anyone help on this.

Kushal Sen Laskar