KUDU INSERT SLOWLY

[sky]

Hi all,
    I do kudu insert sql  through the impala shell, it is very 
slowly.Approximately 4 minutes two thousand insert sqls. Is there any way to 
speed up kudu insert speed?
    Command：
        ./impala-shell.sh -f a.sql
    a.sql:
        insert into table t1 values("a1","b");
        insert into table t1 valuse("a2","b");
        ......