Backport to branch(3) : Reset data chunk id counter for import process

data-loader/core/src/main/java/com/scalar/db/dataloader/core/dataimport/processor/CsvImportProcessor.java

@@ -39,7 +39,7 @@
  */
 public class CsvImportProcessor extends ImportProcessor {
   private static final DataLoaderObjectMapper OBJECT_MAPPER = new DataLoaderObjectMapper();
-  private static final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
+  private final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
 
   /**
    * Creates a new CsvImportProcessor with the specified parameters.

data-loader/core/src/main/java/com/scalar/db/dataloader/core/dataimport/processor/JsonImportProcessor.java

@@ -43,7 +43,7 @@
 public class JsonImportProcessor extends ImportProcessor {
 
   private static final DataLoaderObjectMapper OBJECT_MAPPER = new DataLoaderObjectMapper();
-  private static final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
+  private final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
 
   public JsonImportProcessor(ImportProcessorParams params) {
     super(params);

data-loader/core/src/main/java/com/scalar/db/dataloader/core/dataimport/processor/JsonLinesImportProcessor.java

@@ -37,7 +37,7 @@
 public class JsonLinesImportProcessor extends ImportProcessor {
 
   private static final DataLoaderObjectMapper OBJECT_MAPPER = new DataLoaderObjectMapper();
-  private static final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
+  private final AtomicInteger dataChunkIdCounter = new AtomicInteger(0);
 
   /**
    * Creates a new JsonLinesImportProcessor with the specified parameters.