Add tier dimension to segment/max bytes metric

Author: jtuglu1

server/src/main/java/org/apache/druid/server/metrics/HistoricalMetricsMonitor.java

@@ -57,7 +57,12 @@ public HistoricalMetricsMonitor(
   @Override
   public boolean doMonitor(ServiceEmitter emitter)
   {
-    emitter.emit(new ServiceMetricEvent.Builder().setMetric("segment/max", serverConfig.getMaxSize()));
+    emitter.emit(
+        new ServiceMetricEvent.Builder()
+            .setDimension("tier", serverConfig.getTier())
+            .setDimension("priority", String.valueOf(serverConfig.getPriority()))
+            .setMetric("segment/max", serverConfig.getMaxSize())
+    );
 
     final Object2LongOpenHashMap<String> pendingDeleteSizes = new Object2LongOpenHashMap<>();
 

server/src/test/java/org/apache/druid/server/metrics/HistoricalMetricsMonitorTest.java

@@ -70,6 +70,8 @@ public void testSimple()
     final int priority = 111;
     final String tier = "tier";
 
+    EasyMock.expect(druidServerConfig.getTier()).andReturn(tier).once();
+    EasyMock.expect(druidServerConfig.getPriority()).andReturn(priority).once();
     EasyMock.expect(druidServerConfig.getMaxSize()).andReturn(maxSize).once();
     EasyMock.expect(segmentLoadDropMgr.getSegmentsToDelete()).andReturn(ImmutableList.of(dataSegment)).once();
     EasyMock.expect(druidServerConfig.getTier()).andReturn(tier).once();
@@ -92,7 +94,7 @@ public void testSimple()
     monitor.doMonitor(serviceEmitter);
     EasyMock.verify(druidServerConfig, segmentManager, segmentLoadDropMgr);
 
-    serviceEmitter.verifyValue("segment/max", maxSize);
+    serviceEmitter.verifyValue("segment/max", Map.of("tier", tier, "priority", String.valueOf(priority)), maxSize);
     serviceEmitter.verifyValue(
         "segment/pendingDelete",
         Map.of("tier", tier, "dataSource", dataSource, "priority", String.valueOf(priority)),