我附带了一个脚本来检查名称节点的状态。当我手动运行时，namenode的状态会写入一个文件，当我再次运行时，第二次尝试输出会在旧文件中添加新行。但我已经在cron中计划每15分钟运行一次。但是cron作业覆盖了旧数据，我只能看到上次运行的状态。如何通过cron添加新行？

# !/bin/bash

NOW=$(date +"%m-%d-%Y")
fname=active.$NOW.log
[ ! -f  $fname ] && > /opt/hd/sh/bin/$fname

if [[ $(hdfs haadmin -ns ATcluster -getServiceState nn1) = *active* ]];
then
  echo "`date +"%Y-%m-%d %H:%M:%S"` active NN1" >> /opt/hd/sh/bin/$fname
elif [[ $(hdfs haadmin -ns ATcluster -getServiceState nn2) = *active* ]];
then
  echo "`date +"%Y-%m-%d %H:%M:%S"` active NN2" >> /opt/hd/sh/bin/$fname
else
  echo "`date +"%Y-%m-%d %H:%M:%S"` stopped state" >> /opt/hd/sh/bin/failed.$NOW.log
fi

输出：

cat active.01-1
cat: active.01-1: No such file or directory
[root@hadmat01 bin]# cat active.01-11-2018.log
2018-01-11 06:00:04 active NN1 --> it should write nw output like below through cron job
[root@hadmat01 bin]# cat failed.01-11-2018.log
20180111 00:00:05 stopped state
20180111 00:15:05 stopped state
20180111 00:30:05 stopped state
20180111 00:45:05 stopped state