a very fast test data generator for bigdata
gcc -Wall -o testdata testdata.c
./testdata NUM_OF_LINES > OUTPUT.json
for sample:
[root@instance-1 ~]# ./testdata 1000000 > data.json
[root@instance-1 ~]# ls -lha data.json
-rw-r--r--. 1 root root 76M Apr 19 08:53 data.json
100x faster than perl, or generating data from /dev/urandom