adjust ChunkMetadata size in run time (#1045)

server/src/main/java/org/apache/iotdb/db/conf/adapter/IoTDBConfigDynamicAdapter.java

@@ -92,7 +92,7 @@ public class IoTDBConfigDynamicAdapter implements IDynamicAdapter {
   /**
    * Metadata size of per chunk, the default value is 1.5 KB.
    */
-  private static final long CHUNK_METADATA_SIZE_IN_BYTE = 1536L;
+  private static long CHUNK_METADATA_SIZE_IN_BYTE = 1536L;
 
   /**
    * Average queue length in memtable pool
@@ -265,6 +265,11 @@ public class IoTDBConfigDynamicAdapter implements IDynamicAdapter {
     return totalStorageGroup;
   }
 
+
+  public static void setChunkMetadataSizeInByte(long chunkMetadataSizeInByte) {
+    CHUNK_METADATA_SIZE_IN_BYTE = chunkMetadataSizeInByte;
+  }
+
   /**
    * Only for test
    */

server/src/main/java/org/apache/iotdb/db/engine/cache/ChunkCache.java

@@ -64,7 +64,7 @@ public class ChunkCache {
           long currentSize = RamUsageEstimator.shallowSizeOf(key) + RamUsageEstimator.sizeOf(value);
           averageSize = (averageSize * count) + currentSize / (++count);
           return currentSize;
-        } else if (count < 10000) {
+        } else if (count < 100000) {
           count++;
           return averageSize;
         } else {

server/src/main/java/org/apache/iotdb/db/engine/cache/ChunkMetadataCache.java

@@ -27,6 +27,7 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
 import org.apache.iotdb.db.conf.IoTDBConfig;
 import org.apache.iotdb.db.conf.IoTDBConstant;
 import org.apache.iotdb.db.conf.IoTDBDescriptor;
+import org.apache.iotdb.db.conf.adapter.IoTDBConfigDynamicAdapter;
 import org.apache.iotdb.db.engine.storagegroup.TsFileResource;
 import org.apache.iotdb.db.query.control.FileReaderManager;
 import org.apache.iotdb.db.utils.FileLoaderUtils;
@@ -60,19 +61,31 @@ public class ChunkMetadataCache {
   private AtomicLong cacheHitNum = new AtomicLong();
   private AtomicLong cacheRequestNum = new AtomicLong();
 
-  /**
-   * approximate estimation of chunkMetaData size
-   */
-  private long chunkMetaDataSize = 0;
 
   private ChunkMetadataCache(long memoryThreshold) {
     lruCache = new LRULinkedHashMap<String, List<ChunkMetadata>>(memoryThreshold, true) {
+      int count = 0;
+      long averageChunkMetadataSize = 0;
+
       @Override
       protected long calEntrySize(String key, List<ChunkMetadata> value) {
-        if (chunkMetaDataSize == 0 && !value.isEmpty()) {
-          chunkMetaDataSize = RamUsageEstimator.sizeOf(value.get(0));
+        if (value.isEmpty()) {
+          return key.getBytes().length + averageChunkMetadataSize * value.size();
+        }
+
+        if (count < 10) {
+          long currentSize = RamUsageEstimator.sizeOf(value.get(0));
+          averageChunkMetadataSize = ((averageChunkMetadataSize * count) + currentSize) / (++count);
+          IoTDBConfigDynamicAdapter.setChunkMetadataSizeInByte(averageChunkMetadataSize);
+          return key.getBytes().length + currentSize * value.size();
+        } else if (count < 100000) {
+          count++;
+          return key.getBytes().length + averageChunkMetadataSize * value.size();
+        } else {
+          averageChunkMetadataSize = RamUsageEstimator.sizeOf(value.get(0));
+          count = 1;
+          return key.getBytes().length + averageChunkMetadataSize * value.size();
         }
-        return value.size() * chunkMetaDataSize + key.length() * 2;
       }
     };
   }

server/src/main/java/org/apache/iotdb/db/engine/cache/TimeSeriesMetadataCache.java

@@ -66,7 +66,7 @@ public class TimeSeriesMetadataCache {
           long currentSize = RamUsageEstimator.shallowSizeOf(key) + RamUsageEstimator.sizeOf(value);
           averageSize = ((averageSize * count) + currentSize) / (++count);
           return currentSize;
-        } else if (count < 10000) {
+        } else if (count < 100000) {
           count++;
           return averageSize;
         } else {