Make kudu_sync_ops default to true, adjust the doc

kudu/README.md

@@ -34,12 +34,11 @@ Additional configurations:
 uses 4 tablets. A good rule of thumb is to use 5 per tablet server.
 * `kudu_table_num_replicas`: The number of replicas that each tablet will have. The default is 3. Should
 only be configured to use 1 instead, for single node tests.
-* `kudu_sync_ops`: If the client should buffer data before sending it. The default is false. Should
-always be set to true for the run phase.
+* `kudu_sync_ops`: If the client should wait after every write operation. The default is true.
 * `kudu_block_size`: The data block size used to configure columns. The default is 4096 bytes.
 
 Then, you can run the workload:
 
 ```
-bin/ycsb run kudu -P workloads/workloada -p kudu_sync_ops=true
+bin/ycsb run kudu -P workloads/workloada
 ```

kudu/src/main/java/com/yahoo/ycsb/db/KuduYCSBClient.java

@@ -84,13 +84,13 @@ public class KuduYCSBClient extends com.yahoo.ycsb.DB {
     initClient(debug, tableName, getProperties());
     this.session = client.newSession();
     if (getProperties().getProperty(SYNC_OPS_OPT) != null &&
-        getProperties().getProperty(SYNC_OPS_OPT).equals("true")) {
-      this.session.setFlushMode(KuduSession.FlushMode.AUTO_FLUSH_SYNC);
-    } else {
+        getProperties().getProperty(SYNC_OPS_OPT).equals("false")) {
       this.session.setFlushMode(KuduSession.FlushMode.AUTO_FLUSH_BACKGROUND);
+      this.session.setMutationBufferSpace(100);
+    } else {
+      this.session.setFlushMode(KuduSession.FlushMode.AUTO_FLUSH_SYNC);
     }
 
-    this.session.setMutationBufferSpace(100);
     try {
       this.table = client.openTable(tableName);
     } catch (Exception e) {