Github user srdo commented on a diff in the pull request:
https://github.com/apache/storm/pull/2764#discussion_r208970103
--- Diff:
storm-server/src/main/java/org/apache/storm/daemon/nimbus/Nimbus.java ---
@@ -2807,16 +2897,15 @@ public void launchServer() throws Exception {
}
});
- StormMetricsRegistry.registerGauge("nimbus:num-supervisors",
() -> state.supervisors(null).size());
- StormMetricsRegistry.registerGauge("nimbus:fragmented-memory",
this::fragmentedMemory);
- StormMetricsRegistry.registerGauge("nimbus:fragmented-cpu",
this::fragmentedCpu);
- StormMetricsRegistry.registerGauge("nimbus:available-memory",
() -> nodeIdToResources.get().values()
+ //Be cautious using method reference instead of lambda.
subexpression preceding :: will be evaluated only upon evaluation
+ // Num supervisor, and fragmented resources have been included
in cluster summary
+
StormMetricsRegistry.registerGauge("nimbus:total-available-memory
(nonegative)", () -> nodeIdToResources.get().values()
.parallelStream()
- .mapToDouble(SupervisorResources::getAvailableMem)
+ .mapToDouble(supervisorResources ->
Math.max(supervisorResources.getAvailableMem(), 0))
.sum());
- StormMetricsRegistry.registerGauge("nimbus:available-cpu", ()
-> nodeIdToResources.get().values()
+ StormMetricsRegistry.registerGauge("nimbus:available-cpu
(nonnegative)", () -> nodeIdToResources.get().values()
--- End diff --
Thanks. Sorry I was unclear. What I meant what I don't know if we need to
worry about not changing the names of existing metrics (backward
compatibility). I'm not sure why we want to change the name to include
`(nonnegative)`, and if we want to include it, why not use the same syntax as
the rest of the name (words separated by `-`)?
---
