[fix][metrics] fixed ProxyStats to use common.stats.JvmMetrics

[heesung-sohn]

Motivation

We have the following error from websocket service when running different GCs other than G1GC. This is because websocket uses its own org.apache.pulsar.websocket.stats.JvmMetrics class, which always looks up G1GC stats, regardless of the runtime GC. I think we can replace this duplicated org.apache.pulsar.websocket.stats.JvmMetrics with the common one org.apache.pulsar.common.stats.JvmMetrics, which supports different GC metrics.

2022-05-20T10:54:29,322-0700 [pulsar-websocket-57-2] ERROR org.apache.pulsar.websocket.stats.JvmMetrics - Failed to collect GC stats: java.lang:type=GarbageCollector,name=G1 Young Generation

Modifications

• Removed org.apache.pulsar.websocket.stats.JvmMetrics
• Replaced org.apache.pulsar.websocket.stats.JvmMetrics dependency with org.apache.pulsar.common.stats.JvmMetrics in ProxyStats.

Behavior changes

Before

### when running websocket on G1GC
curl http://localhost:8080/admin/v2/proxy-stats/metrics/
[{"metrics":{
"jvm_gc_old_count":0,
"jvm_gc_old_pause":0,
"jvm_gc_young_count":0,
"jvm_gc_young_pause":0,
"jvm_heap_used":52622168,
"jvm_max_direct_memory":4294967296,
"jvm_max_memory":2147483648,
"jvm_thread_cnt":24,
"jvm_total_memory":2147483648},
"dimensions":{"system":"jvm"}}]


### when running websocket on ZGC
websocket.stats.JvmMetrics constantly fails to collect G1GC metrics and throws the error.

2022-05-20T15:26:00,499-0700 [pulsar-websocket-2-1] ERROR org.apache.pulsar.websocket.stats.JvmMetrics - Failed to collect GC stats: java.lang:type=GarbageCollector,name=G1 Young Generation
...

curl http://localhost:8080/admin/v2/proxy-stats/metrics/
[{"metrics":{
"jvm_gc_old_count":0,
"jvm_gc_old_pause":0,
"jvm_gc_young_count":0,
"jvm_gc_young_pause":0,
"jvm_heap_used":117440512,
"jvm_max_direct_memory":4294967296,
"jvm_max_memory":2147483648,
"jvm_thread_cnt":24,
"jvm_total_memory":2147483648},
"dimensions":{"system":"jvm"}}]

After

### when running websocket on G1GC

curl http://localhost:8080/admin/v2/proxy-stats/metrics/
[{"metrics":{
"jvm_direct_memory_used":0,
"jvm_gc_old_count":0,
"jvm_gc_old_pause":0,
"jvm_gc_young_count":0,
"jvm_gc_young_pause":0,
"jvm_heap_used":58425032,
"jvm_max_direct_memory":4294967296,
"jvm_max_memory":2147483648,
"jvm_thread_cnt":28,
"jvm_total_memory":2147483648,
"prx_default_pool_allocated":0,
"prx_default_pool_used":0},
"dimensions":{"metric":"jvm_metrics"}}]

### when running websocket on ZGC
curl http://localhost:8080/admin/v2/proxy-stats/metrics/
[{"metrics":{
"jvm_ZGC Cycles_gc_count":0,
"jvm_ZGC Cycles_gc_pause":0,
"jvm_ZGC Pauses_gc_count":0,
"jvm_ZGC Pauses_gc_pause":0,
"jvm_direct_memory_used":0,
"jvm_full_gc_count":1,
"jvm_full_gc_pause":0,
"jvm_heap_used":117440512,
"jvm_max_direct_memory":4294967296,
"jvm_max_memory":2147483648,
"jvm_thread_cnt":24,
"jvm_total_memory":2147483648,
"prx_default_pool_allocated":0,
"prx_default_pool_used":0},
"dimensions":{"metric":"jvm_metrics"}}]

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (yes / no / don't know)
• The default values of configurations: (yes / no)
• The wire protocol: (yes / no)
• The rest endpoints: (yes / no)
• The admin cli options: (yes / no)
• Anything that affects deployment: (yes / no / don't know)

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[tjiuming]

LGTM

[tuteng]

This exception was thrown in version 2.10, so consider releasing it to version 2.10.x, add label cherry-picked/branch-2.10 and release/2.10.2

[codelipenghui]

@tuteng I have removed the cherry-picked/branch-2.10 label. We are using this label to check if the PR has been cherry-picked. After cherry-picked, we will add this label.