amazon ec2 - AWS ELB Latency issue

I have two c3.2xlarge EC2 machines with Ubuntu environment both in us-west-2a AZ. Both contains same code with mySQL database from AWS RDS (db.r3.2xlarge). Both instances are added to an ELB. Both has one cron scheduled that runs twice in a day.

ELB has been configured to raise the alarm once the threshold crosses 5.0. The CPU utilization of both the instances are by average 30 - 50. At peak hours hits 100% for a minute or two and then returns to normal. But ELB constantly raises alarm thrice a day. At this time, both instances has

CPU     - ~50%
Memory  - total - 14979
          used  - ~6000

          free  - ~9000
RDS CPU - ~30%
          Connections - 200 to 300 /5,000

According to this https://aws.amazon.com/premiumsupport/knowledge-center/elb-latency-troubleshooting/ I could find nothing wrong with the instances. But still latency hits the peak and both instance fails to respond.

Till now, I am just removing one of the instance from the load balancer, restart the apache and then load it back and do the same for other instance. This does the job perfectly alright and the instances and ELB works good for next 6-10 hours. But this is not acceptable since, every day twice or thrice one has to take care of the server, needs it to restart.

I need to know, if there is anything wrong or any steps to be taken to resolve this problem.

Apache server-status contains too many such (~200/250 processes):

7-0 23176   1/2373/5118 C   30.95   3986    0   0.0 7.01    15.78   127.0.0.1   ip-xxx-xxx-xxx-xxx.us-west-2.comp   OPTIONS * HTTP/1.0