Merge pull request #1679 from apache/real_fix_wal

restore scheduleWithFixedDelay in wal manager to accelerate insertion

server/src/assembly/resources/conf/iotdb-engine.properties

@@ -53,7 +53,7 @@ flush_wal_threshold=10000
 # The cycle when insert ahead log is periodically forced to be written to disk(in milliseconds)
 # If force_wal_period_in_ms = 0 it means force insert ahead log to be written to disk after each refreshment
 # Set this parameter to 0 may slow down the ingestion on slow disk.
-force_wal_period_in_ms=10
+force_wal_period_in_ms=100
 
 ####################
 ### Directory Configuration

server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java

@@ -159,7 +159,7 @@ public class IoTDBConfig {
    * The cycle when write ahead log is periodically forced to be written to disk(in milliseconds) If
    * set this parameter to 0 it means call outputStream.force(true) after every each insert
    */
-  private long forceWalPeriodInMs = 10;
+  private long forceWalPeriodInMs = 100;
 
   /**
    * Size of log buffer in each log node(in byte). If WAL is enabled and the size of a insert plan

server/src/main/java/org/apache/iotdb/db/writelog/manager/MultiFileLogNodeManager.java

@@ -46,23 +46,23 @@ public class MultiFileLogNodeManager implements WriteLogNodeManager, IService {
   private ScheduledExecutorService executorService;
   private IoTDBConfig config = IoTDBDescriptor.getInstance().getConfig();
 
-  private final void forceTask(){
-        if (IoTDBDescriptor.getInstance().getConfig().isReadOnly()) {
-          logger.warn("system mode is read-only, the force flush WAL task is stopped");
-          return;
-        }
-        if (Thread.interrupted()) {
-          logger.info("WAL force thread exits.");
-          return;
-        }
-
-        for (WriteLogNode node : nodeMap.values()) {
-          try {
-            node.forceSync();
-          } catch (IOException e) {
-            logger.error("Cannot force {}, because ", node, e);
-          }
-        }
+  private final void forceTask() {
+    if (IoTDBDescriptor.getInstance().getConfig().isReadOnly()) {
+      logger.warn("system mode is read-only, the force flush WAL task is stopped");
+      return;
+    }
+    if (Thread.interrupted()) {
+      logger.info("WAL force thread exits.");
+      return;
+    }
+
+    for (WriteLogNode node : nodeMap.values()) {
+      try {
+        node.forceSync();
+      } catch (IOException e) {
+        logger.error("Cannot force {}, because ", node, e);
+      }
+    }
   }
 
   private MultiFileLogNodeManager() {
@@ -117,7 +117,7 @@ public class MultiFileLogNodeManager implements WriteLogNodeManager, IService {
       }
       if (config.getForceWalPeriodInMs() > 0) {
         executorService = Executors.newSingleThreadScheduledExecutor();
-        executorService.scheduleAtFixedRate(this::forceTask, config.getForceWalPeriodInMs(),
+        executorService.scheduleWithFixedDelay(this::forceTask, config.getForceWalPeriodInMs(),
             config.getForceWalPeriodInMs(), TimeUnit.MILLISECONDS);
       }
     } catch (Exception e) {