[BUG] metric wait_time form default-metrics.toml does not add labels in prometheus metrics

[romankspb]

Description

In default-metrics.toml defined metric with labels

          [[metric]]
          context = "wait_time"
          labels = [ "inst_id", "wait_class", "con_id" ]
          metricsdesc = { time_waited_sec_total="counter metric from system_wait_class view in Oracle." }
          metricstype = { time_waited_sec_total = "counter" }
          fieldtoappend= "wait_class"
          request = '''
          select
            inst_id,
            wait_class,
            round(time_waited/100,3) time_waited_sec_total,
            con_id
          from gv$system_wait_class
          where wait_class <> 'Idle'
          group by inst_id, wait_class, con_id, round(time_waited/100,3)

but exporter creates metrics without labels inst_id, wait_class, con_id as described in documentation

$ k -n oracle-db-observability-exporter exec -it deploy/oracle-db-observability-exporter -- curl http://oracle-db-observability-exporter.oracle-db-observability-exporter.svc.cluster.local:9161/metrics | grep wait_time | grep PALM | grep -v \#
oracledb_wait_time_administrative{database="PALMIRA"} 3231.3
oracledb_wait_time_application{database="PALMIRA"} 39697.56
oracledb_wait_time_cluster{database="PALMIRA"} 7.05280253e+06
oracledb_wait_time_commit{database="PALMIRA"} 570079.2
oracledb_wait_time_concurrency{database="PALMIRA"} 402058.46
oracledb_wait_time_configuration{database="PALMIRA"} 6.18485476e+06
oracledb_wait_time_network{database="PALMIRA"} 28088.17
oracledb_wait_time_other{database="PALMIRA"} 1.80085476e+06
oracledb_wait_time_scheduler{database="PALMIRA"} 205.93
oracledb_wait_time_system_io{database="PALMIRA"} 2.4603302e+06
oracledb_wait_time_user_io{database="PALMIRA"} 1.916006641e+07

Environment

• OS: Official docker image
• Oracle Database version: 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.26.0.0.0
• Exporter version: 2.0.4

Screenshots / Logs

[anders-swanson]

Thanks for reporting this, I'll check it out 👍

[anders-swanson]

This is a bug around how FieldToAppend is handled. I don't really like that we have FieldToAppend in the default metrics, because it explodes the cardinality of metrics (rather than just using a label, like wait_class), but I'll see what I can do to fix it.

[anders-swanson]

OK, think I have a fix in #351, seeing labels in fieldtoappend metrics now. Thanks again for reporting this bug!