public void requestMemory(final long size) {
    memoryBlock.forceAllocateWithoutLimitation(size);
    if (memoryBlock.getUsedMemoryInBytes() >= memoryBlock.getTotalMemorySizeInBytes()) {
      synchronized (allowToCreateNewSeriesLock) {
        if (allowToCreateNewSeries
            && memoryBlock.getUsedMemoryInBytes() >= memoryBlock.getTotalMemorySizeInBytes()) {
          if (needLog) {
            logger.warn(
                "Current series memory {} is too large...", memoryBlock.getUsedMemoryInBytes());
          } else {
            logger.debug(
                "Current series memory {} is too large...", memoryBlock.getUsedMemoryInBytes());
          }
          allowToCreateNewSeries = false;
        }
      }
    }
  }
This class is used to record the global statistics of SchemaEngine in Memory mode.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/rescon/MemSchemaEngineStatistics.java