HDDS-15065. Reduce Ratis snapshot gap to fix SCM flush delay.

Author: priyeshkaratha

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/ScmConfigKeys.java

@@ -584,15 +584,6 @@ public final class ScmConfigKeys {
   public static final long OZONE_SCM_HA_RATIS_SNAPSHOT_THRESHOLD_DEFAULT =
           1000L;
 
-  /**
-   * the config will transfer value to ratis config
-   * raft.server.snapshot.creation.gap, used by ratis to take snapshot
-   * when manual trigger using api.
-   */
-  public static final String OZONE_SCM_HA_RATIS_SNAPSHOT_GAP
-      = "ozone.scm.ha.ratis.server.snapshot.creation.gap";
-  public static final long OZONE_SCM_HA_RATIS_SNAPSHOT_GAP_DEFAULT =
-      1024L;
   public static final String OZONE_SCM_HA_RATIS_SNAPSHOT_DIR =
           "ozone.scm.ha.ratis.snapshot.dir";
 

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -4168,12 +4168,6 @@
       topology cluster tree from SCM.
     </description>
   </property>
-  <property>
-    <name>ozone.scm.ha.ratis.server.snapshot.creation.gap</name>
-    <value>1024</value>
-    <tag>SCM, OZONE</tag>
-    <description>Raft snapshot gap index after which snapshot can be taken.</description>
-  </property>
   <property>
     <name>ozone.scm.ha.dbtransactionbuffer.flush.interval</name>
     <value>60s</value>

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/ha/RatisUtil.java

@@ -54,6 +54,8 @@
  */
 public final class RatisUtil {
 
+  public static final long SCM_RAFT_SNAPSHOT_GAP = 1L;
+
   private RatisUtil() {
   }
 
@@ -231,9 +233,7 @@ private static void setRaftSnapshotProperties(
     Snapshot.setAutoTriggerThreshold(properties,
         ozoneConf.getLong(ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_THRESHOLD,
                 ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_THRESHOLD_DEFAULT));
-    Snapshot.setCreationGap(properties,
-        ozoneConf.getLong(ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_GAP,
-            ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_GAP_DEFAULT));
+    Snapshot.setCreationGap(properties, SCM_RAFT_SNAPSHOT_GAP);
   }
 
   public static void checkRatisException(IOException e, String port,

hadoop-ozone/integration-test-recon/src/test/java/org/apache/hadoop/ozone/recon/AbstractTestStorageDistributionEndpoint.java

@@ -21,7 +21,6 @@
 import static org.apache.hadoop.hdds.HddsConfigKeys.HDDS_HEARTBEAT_INTERVAL;
 import static org.apache.hadoop.hdds.HddsConfigKeys.HDDS_SCM_WAIT_TIME_AFTER_SAFE_MODE_EXIT;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_HA_DBTRANSACTIONBUFFER_FLUSH_INTERVAL;
-import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_GAP;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_HEARTBEAT_PROCESS_INTERVAL;
 import static org.apache.hadoop.ozone.OzoneConfigKeys.OZONE_BLOCK_DELETING_SERVICE_INTERVAL;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_DIR_DELETING_SERVICE_INTERVAL;
@@ -146,7 +145,6 @@ protected static void initializeCluster(int numDatanodes) throws Exception {
     conf.setTimeDuration(OZONE_DIR_DELETING_SERVICE_INTERVAL, 100, TimeUnit.MILLISECONDS);
     conf.setTimeDuration(OZONE_BLOCK_DELETING_SERVICE_INTERVAL, 100, TimeUnit.MILLISECONDS);
     conf.setTimeDuration(OZONE_SCM_HEARTBEAT_PROCESS_INTERVAL, 100, TimeUnit.MILLISECONDS);
-    conf.setLong(OZONE_SCM_HA_RATIS_SNAPSHOT_GAP, 1L);
     conf.setTimeDuration(HDDS_HEARTBEAT_INTERVAL, 50, TimeUnit.MILLISECONDS);
     conf.setTimeDuration(HDDS_CONTAINER_REPORT_INTERVAL, 200, TimeUnit.MILLISECONDS);
     conf.setTimeDuration(OZONE_SCM_HA_DBTRANSACTIONBUFFER_FLUSH_INTERVAL, 500, TimeUnit.MILLISECONDS);

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/hdds/scm/TestDatanodeSCMNodesReconfiguration.java

@@ -74,7 +74,6 @@ public void init() throws Exception {
     conf.set(ScmConfigKeys.OZONE_SCM_PIPELINE_CREATION_INTERVAL, "10s");
     conf.set(ScmConfigKeys.OZONE_SCM_HA_DBTRANSACTIONBUFFER_FLUSH_INTERVAL,
         "5s");
-    conf.set(ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_GAP, "1");
     conf.setTimeDuration(OZONE_SCM_HEARTBEAT_PROCESS_INTERVAL, 100,
         MILLISECONDS);
     conf.setTimeDuration(HDDS_HEARTBEAT_INTERVAL, 1, SECONDS);

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/hdds/scm/TestStorageContainerManagerHA.java

@@ -53,7 +53,6 @@ public void init() throws Exception {
     conf.set(ScmConfigKeys.OZONE_SCM_PIPELINE_CREATION_INTERVAL, "10s");
     conf.set(ScmConfigKeys.OZONE_SCM_HA_DBTRANSACTIONBUFFER_FLUSH_INTERVAL,
         "5s");
-    conf.set(ScmConfigKeys.OZONE_SCM_HA_RATIS_SNAPSHOT_GAP, "1");
     cluster = MiniOzoneCluster.newHABuilder(conf)
         .setOMServiceId("om-service-test1")
         .setSCMServiceId("scm-service-test1")