fix issues

Author: mrproliu

docs/en/changes/changes.md

@@ -13,7 +13,7 @@
     source tar from the website and publish them to your private maven repository.
 * [Breaking Change] Remove H2 as storage option permanently. BanyanDB 0.8(OAP 10.2 required) is easy, stable and 
   production-ready. Don't need H2 as default storage anymore.
-* Support `labelCount` function in the OAL engine.
+* Support `labelAvg` function in the OAL engine.
 * Added `maxLabelCount` parameter in the `labelCount` function of OAL to limit the number of labels can be counted.
 
 #### OAP Server

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/metrics/LabelAvgMetrics.java

@@ -68,7 +68,7 @@ public LabelAvgMetrics() {
     }
 
     @Entrance
-    public final void combine(@Arg String label, @Arg long count, @DefaultValue("1024") int maxLabelCount) {
+    public final void combine(@Arg String label, @Arg long count, @DefaultValue("50") int maxLabelCount) {
         this.isCalculated = false;
         this.maxLabelCount = maxLabelCount;
         this.summation.valueAccumulation(label, count, maxLabelCount);

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/metrics/LabelCountMetrics.java

@@ -58,7 +58,7 @@ public LabelCountMetrics() {
     }
 
     @Entrance
-    public final void combine(@Arg String label, @ConstOne long count, @DefaultValue("1024") int maxLabelCount) {
+    public final void combine(@Arg String label, @ConstOne long count, @DefaultValue("50") int maxLabelCount) {
         this.isCalculated = false;
         this.maxLabelCount = maxLabelCount;
         this.dataset.valueAccumulation(label, count, maxLabelCount);