named logs are not rotated upon logroate configuration in Red Hat Enterprise Linux 6

Issue

• DNS queries are captured in a file /var/log/query.log.
• I planned to create a logrotate for 75MB and upto 2 backup files due to a limitation of storage size.
• I moved logrotate cron job into cron.hourly.
• DNS server's log rotate works, but it didn't happen hourly. It happened in smaller period like 20 minutes.

# ll -h /var/log/query.log*
-rw-r--r-- 1 named named 114M Mar 30 14:24 /var/log/query.log
-rw-r--r-- 1 named named 201M Mar 30 14:13 /var/log/query.log.0
-rw-r--r-- 1 named named 201M Mar 30 13:53 /var/log/query.log.1
-rw-r--r-- 1 named named 201M Mar 30 13:33 /var/log/query.log.2

• Why is it rotated upon the defined logrotate configuration?