[NO ISSUE][OTH] Add I/O related helper methods

- user model changes: no
- storage format changes: no
- interface changes: no

Details:
Add I/O related helper methods

Change-Id: I15167705e1fad0a5331ecc736d6867eff845f417
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/17931
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Wail Alkowaileet <wael.y.k@gmail.com>
Reviewed-by: Wail Alkowaileet <wael.y.k@gmail.com>
Reviewed-by: Murtadha Hubail <mhubail@apache.org>
diff --git a/asterixdb/asterix-app/src/test/java/org/apache/asterix/api/common/LocalCloudUtil.java b/asterixdb/asterix-app/src/test/java/org/apache/asterix/api/common/LocalCloudUtil.java
index 773fa4e..9e3fdc4 100644
--- a/asterixdb/asterix-app/src/test/java/org/apache/asterix/api/common/LocalCloudUtil.java
+++ b/asterixdb/asterix-app/src/test/java/org/apache/asterix/api/common/LocalCloudUtil.java
@@ -50,8 +50,10 @@
     }
 
     public static void main(String[] args) {
+        String cleanStartString = System.getProperty("cleanup.start", "true");
+        boolean cleanStart = Boolean.parseBoolean(cleanStartString);
         // Change to 'true' if you want to delete "s3mock" folder on start
-        startS3CloudEnvironment(true);
+        startS3CloudEnvironment(cleanStart);
     }
 
     public static S3Mock startS3CloudEnvironment(boolean cleanStart) {
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/replication/AllDatasetsReplicationStrategy.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/replication/AllDatasetsReplicationStrategy.java
index c969777..84f0a39 100644
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/replication/AllDatasetsReplicationStrategy.java
+++ b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/replication/AllDatasetsReplicationStrategy.java
@@ -19,6 +19,7 @@
 package org.apache.asterix.common.replication;
 
 public class AllDatasetsReplicationStrategy implements IReplicationStrategy {
+    public static final IReplicationStrategy INSTANCE = new AllDatasetsReplicationStrategy();
 
     @Override
     public boolean isMatch(int datasetId) {
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/storage/StorageIOStats.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/storage/StorageIOStats.java
index da4578f..b58f63d 100644
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/storage/StorageIOStats.java
+++ b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/storage/StorageIOStats.java
@@ -47,4 +47,8 @@
     public int getPendingReplications() {
         return pendingReplications;
     }
+
+    public int getTotalPendingOperations() {
+        return pendingFlushes + pendingMerges + pendingReplications;
+    }
 }