获取redis实例中最大的top-N key

需求：获取redis实例中最大的top-N key

说明：由于redis 4.x才引入了memory usage keyname的语法。3.x不支持！

db_ip=5.5.5.101
db_port=6379
password=abc123
cursor=0
cnt=100
new_cursor=0

function get_key()
{
redis-cli -h $db_ip -p $db_port -a $password scan $1 count $cnt > scan_tmp_result
new_cursor=`sed -n '1p' scan_tmp_result`
sed -n '2,$p' scan_tmp_result > scan_result
}

function get_keysize()
{
cat $1 |while read line
do
key_size=`redis-cli -h $db_ip -p $db_port -a $password memory usage $line`
echo $line $key_size >> key_sizes.txt
done
}

get_key $cursor
get_keysize scan_result

while [ $cursor -ne $new_cursor ]
do
get_key $new_cursor
get_keysize scan_result
done

cat key_sizes.txt | sort -nrk2 | sed -n "1,$1p"
rm -rf scan_tmp_result
rm -rf scan_result
rm -rf key_sizes.txt

 测试：

[redis@lxd-vm1 ~]$ sh get_bigkeys_top.sh 5
test2 12325
test 1589
c_9999 49
c_9998 49
c_9997 49