Optimize metrics of minute dimensionality persistence, don't save metric of...

Optimize metrics of minute dimensionality persistence, don't save metric of being default value. (#8066)

Optimize metrics of minute dimensionality persistence.
- The value of metrics, which has declaration of the default value and current value equals the default value logically, the whole row wouldn't be pushed into database.
- Add self-observability `metrics_persistence_skipped` metric to measure the number of skipped metrics.
- SLA(percent function), Apdex, AvgLong(MAL mostly) metrics are mostly optimized because of this. Such as a full-failing error(0% successful rate) and unhealthy(apdex=0) are not costing the storage.
- Hour/Day dimensionalities metrics are not changed, as they cover long duration.
- Fix `max` function in OAL doesn't support negative long.

CHANGES.md

@@ -43,6 +43,9 @@ Release Notes.
 * Fix ElasticSearch implementation of `queryMetricsValues` and `readLabeledMetricsValues` doesn't fill default values
   when no available data in the ElasticSearch server.
 * Fix config yaml data type conversion bug when meets special character like !.
+* Optimize metrics of minute dimensionality persistence. The value of metrics, which has declaration of the default
+  value and current value equals the default value logically, the whole row wouldn't be pushed into database.
+* Fix `max` function in OAL doesn't support negative long.
 
 #### UI
 
@@ -62,9 +65,9 @@ Release Notes.
 #### Documentation
 
 * Enhance documents about the data report and query protocols.
-* Restructure documents about receivers and fetchers. 
-  1. Remove general receiver and fetcher docs
-  2. Add more specific menu with docs to help users to find documents easier.
+* Restructure documents about receivers and fetchers.
+    1. Remove general receiver and fetcher docs
+    2. Add more specific menu with docs to help users to find documents easier.
 
 All issues and pull requests are [here](https://github.com/apache/skywalking/milestone/101?closed=1)
 

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgFunction.java

@@ -213,4 +213,14 @@ public abstract class AvgFunction extends Metrics implements AcceptableValue<Lon
     public int hashCode() {
         return Objects.hash(entityId, getTimeBucket());
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/latest/LatestFunction.java

@@ -182,4 +182,14 @@ public abstract class LatestFunction extends Metrics implements AcceptableValue<
     public int hashCode() {
         return Objects.hash(entityId, getTimeBucket());
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/sum/SumFunction.java

@@ -183,4 +183,14 @@ public abstract class SumFunction extends Metrics implements AcceptableValue<Lon
     public int hashCode() {
         return Objects.hash(getEntityId(), getTimeBucket());
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -95,4 +95,14 @@ public abstract class ApdexMetrics extends Metrics implements IntValueHolder {
     public int getValue() {
         return value;
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -57,5 +57,15 @@ public abstract class CPMMetrics extends Metrics implements LongValueHolder {
     public void calculate() {
         this.value = total / getDurationInMinute();
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }
 

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

@@ -51,4 +51,14 @@ public abstract class CountMetrics extends Metrics implements LongValueHolder {
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -64,4 +64,15 @@ public abstract class DoubleAvgMetrics extends Metrics implements DoubleValueHol
     public final void calculate() {
         this.value = this.summation / this.count;
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        // Value in the query stage will ignore decimal places after a decimal point
+        return Double.valueOf(value).longValue() == 0;
+    }
 }

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

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.apache.skywalking.oap.server.core.analysis.metrics;
+
+/**
+ * HavingDefaultValue interface defines a capability for the metric implementations, which has the declaration of the
+ * default value.
+ *
+ * For the declared metrics, the OAP server would skip the persistence of minute dimensionality metrics to reduce
+ * resource costs for the database, when the value of the metric is the default.
+ */
+public interface HavingDefaultValue {
+    /**
+     * @return true if the implementation of this metric has the definition of default value.
+     */
+    default boolean haveDefault() {
+        return false;
+    }
+
+    /**
+     * @return true when the latest value equals the default value.
+     */
+    default boolean isDefaultValue() {
+        return false;
+    }
+}

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

@@ -64,4 +64,14 @@ public abstract class LongAvgMetrics extends Metrics implements LongValueHolder
     public final void calculate() {
         this.value = this.summation / this.count;
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -52,4 +52,15 @@ public abstract class MaxDoubleMetrics extends Metrics implements DoubleValueHol
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        // Value in the query stage will ignore decimal places after a decimal point
+        return Double.valueOf(value).longValue() == 0;
+    }
 }

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

@@ -25,9 +25,6 @@ import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.Metrics
 import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.SourceFrom;
 import org.apache.skywalking.oap.server.core.storage.annotation.Column;
 
-/**
- *
- **/
 @MetricsFunction(functionName = "max")
 public abstract class MaxLongMetrics extends Metrics implements LongValueHolder {
 
@@ -36,7 +33,7 @@ public abstract class MaxLongMetrics extends Metrics implements LongValueHolder
     @Getter
     @Setter
     @Column(columnName = VALUE, dataType = Column.ValueDataType.COMMON_VALUE)
-    private long value;
+    private long value = Long.MIN_VALUE;
 
     @Entrance
     public final void combine(@SourceFrom long count) {
@@ -55,4 +52,14 @@ public abstract class MaxLongMetrics extends Metrics implements LongValueHolder
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -33,7 +33,7 @@ import org.apache.skywalking.oap.server.core.storage.annotation.Column;
 @EqualsAndHashCode(of = {
     "timeBucket"
 })
-public abstract class Metrics extends StreamData implements StorageData {
+public abstract class Metrics extends StreamData implements StorageData, HavingDefaultValue {
 
     public static final String TIME_BUCKET = "time_bucket";
     public static final String ENTITY_ID = "entity_id";

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

@@ -52,4 +52,15 @@ public abstract class MinDoubleMetrics extends Metrics implements DoubleValueHol
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        // Value in the query stage will ignore decimal places after a decimal point
+        return Double.valueOf(value).longValue() == 0;
+    }
 }

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

@@ -52,4 +52,14 @@ public abstract class MinLongMetrics extends Metrics implements LongValueHolder
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -69,4 +69,14 @@ public abstract class PercentMetrics extends Metrics implements IntValueHolder {
     public int getValue() {
         return percentage;
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return percentage == 0;
+    }
 }

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

@@ -106,4 +106,14 @@ public abstract class PxxMetrics extends Metrics implements IntValueHolder {
             }
         }
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

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

@@ -73,4 +73,14 @@ public abstract class RateMetrics extends Metrics implements IntValueHolder {
     public int getValue() {
         return percentage;
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return percentage == 0;
+    }
 }

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

@@ -51,4 +51,14 @@ public abstract class SumMetrics extends Metrics implements LongValueHolder {
     @Override
     public void calculate() {
     }
+
+    @Override
+    public boolean haveDefault() {
+        return true;
+    }
+
+    @Override
+    public boolean isDefaultValue() {
+        return value == 0;
+    }
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentWorker.java

@@ -28,10 +28,6 @@ import java.util.Optional;
 import java.util.Properties;
 import java.util.stream.Collectors;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.skywalking.oap.server.library.datacarrier.DataCarrier;
-import org.apache.skywalking.oap.server.library.datacarrier.consumer.BulkConsumePool;
-import org.apache.skywalking.oap.server.library.datacarrier.consumer.ConsumerPoolFactory;
-import org.apache.skywalking.oap.server.library.datacarrier.consumer.IConsumer;
 import org.apache.skywalking.oap.server.core.UnexpectedException;
 import org.apache.skywalking.oap.server.core.analysis.data.MergableBufferedData;
 import org.apache.skywalking.oap.server.core.analysis.data.ReadWriteSafeCache;
@@ -41,6 +37,10 @@ import org.apache.skywalking.oap.server.core.storage.IMetricsDAO;
 import org.apache.skywalking.oap.server.core.storage.model.Model;
 import org.apache.skywalking.oap.server.core.worker.AbstractWorker;
 import org.apache.skywalking.oap.server.library.client.request.PrepareRequest;
+import org.apache.skywalking.oap.server.library.datacarrier.DataCarrier;
+import org.apache.skywalking.oap.server.library.datacarrier.consumer.BulkConsumePool;
+import org.apache.skywalking.oap.server.library.datacarrier.consumer.ConsumerPoolFactory;
+import org.apache.skywalking.oap.server.library.datacarrier.consumer.IConsumer;
 import org.apache.skywalking.oap.server.library.module.ModuleDefineHolder;
 import org.apache.skywalking.oap.server.telemetry.TelemetryModule;
 import org.apache.skywalking.oap.server.telemetry.api.CounterMetrics;
@@ -68,6 +68,7 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
     private final boolean supportUpdate;
     private long sessionTimeout;
     private CounterMetrics aggregationCounter;
+    private CounterMetrics skippedMetricsCounter;
     /**
      * The counter for the round of persistent.
      */
@@ -82,6 +83,11 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
      * @since 8.7.0 TTL settings from {@link org.apache.skywalking.oap.server.core.CoreModuleConfig#getMetricsDataTTL()}
      */
     private int metricsDataTTL;
+    /**
+     * @since 8.9.0 The persistence of minute dimensionality metrics will be skipped if the value of the metric is the
+     * default.
+     */
+    private boolean skipDefaultValueMetric;
 
     MetricsPersistentWorker(ModuleDefineHolder moduleDefineHolder, Model model, IMetricsDAO metricsDAO,
                             AbstractWorker<Metrics> nextAlarmWorker, AbstractWorker<ExportEvent> nextExportWorker,
@@ -100,6 +106,7 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
         this.persistentCounter = 0;
         this.persistentMod = 1;
         this.metricsDataTTL = metricsDataTTL;
+        this.skipDefaultValueMetric = true;
 
         String name = "METRICS_L2_AGGREGATION";
         int size = BulkConsumePool.Creator.recommendMaxSize() / 8;
@@ -124,6 +131,11 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
             new MetricsTag.Keys("metricName", "level", "dimensionality"),
             new MetricsTag.Values(model.getName(), "2", model.getDownsampling().getName())
         );
+        skippedMetricsCounter = metricsCreator.createCounter(
+            "metrics_persistence_skipped", "The number of metrics skipped in persistence due to be in default value",
+            new MetricsTag.Keys("metricName", "dimensionality"),
+            new MetricsTag.Values(model.getName(), model.getDownsampling().getName())
+        );
         SESSION_TIMEOUT_OFFSITE_COUNTER++;
     }
 
@@ -141,6 +153,12 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
              null, null, null,
              enableDatabaseSession, supportUpdate, storageSessionTimeout, metricsDataTTL
         );
+
+        // Skipping default value mechanism only works for minute dimensionality.
+        // Metrics in hour and day dimensionalities would not apply this as duration is too long,
+        // applying this could make precision of hour/day metrics to be lost easily.
+        this.skipDefaultValueMetric = false;
+
         // For a down-sampling metrics, we prolong the session timeout for 4 times, nearly 5 minutes.
         // And add offset according to worker creation sequence, to avoid context clear overlap,
         // eventually optimize load of IDs reading.
@@ -225,12 +243,22 @@ public class MetricsPersistentWorker extends PersistenceWorker<Metrics> {
                         continue;
                     }
                     cachedMetrics.calculate();
-                    prepareRequests.add(metricsDAO.prepareBatchUpdate(model, cachedMetrics));
+                    if (skipDefaultValueMetric && cachedMetrics.haveDefault() && cachedMetrics.isDefaultValue()) {
+                        // Skip metrics in default value
+                        skippedMetricsCounter.inc();
+                    } else {
+                        prepareRequests.add(metricsDAO.prepareBatchUpdate(model, cachedMetrics));
+                    }
                     nextWorker(cachedMetrics);
                     cachedMetrics.setLastUpdateTimestamp(timestamp);
                 } else {
                     metrics.calculate();
-                    prepareRequests.add(metricsDAO.prepareBatchInsert(model, metrics));
+                    if (skipDefaultValueMetric && metrics.haveDefault() && metrics.isDefaultValue()) {
+                        // Skip metrics in default value
+                        skippedMetricsCounter.inc();
+                    } else {
+                        prepareRequests.add(metricsDAO.prepareBatchInsert(model, metrics));
+                    }
                     nextWorker(metrics);
                     metrics.setLastUpdateTimestamp(timestamp);
                 }