how to reduce wait time in perl - perl

Question

I have script that queries a database a variable number of times per second.
For example, to achieve 36,000 queries per hour we input 600 queries per minute into our script. 600 x 60 = 36,000
This is the output we get you can see the delay between each query
{1} [2019-11-06 21:38:01.313]
{1} [2019-11-06 21:38:01.413]
{1} [2019-11-06 21:38:01.513]
{1} [2019-11-06 21:38:01.613]
{1} [2019-11-06 21:38:01.713]
{1} [2019-11-06 21:38:01.813]
My problem is we are missing out on that 0.0100 because we have a wait time inplace.
rates per minute = varies we can change this to a max of 960 queries per min but we would want fourmla that is flexible for 0-960.
my $wait_time = (1 / $rpm) * 60 * 1(connection); (max of 4 connections) wait time increases based on number of connections
Does anyone know how to reduce the wait time in between queries ?
thanks
This is the code line
my $wait_time = (1 / $rpm) * 60 * 1;
So when i enter in 600 queries per min
This code line calcuates the wait time based on number of connection we have
my $wait_time = (1 / 600) * 60 * 1;
1/600 * 60 * 1 = WAIT: 0.1

Answer 1

Well, your processing of the query needs time. A fragile solution, if i interpret your problem right, is to measure the time the current processing takes and substract that from the next sleep time. Of course that would break if the processing time equals or exceeds the sleep time.
A clean solution would be to have a dedicated main loop that does nothing but sleeping and firing off queries in separate threads.

Answer 2

I'm not sure if this will help because I have a very hard time understanding your question. I think you are concerned that you aren't making queries at the rate you desire.
It could be because you think of the wait time as being static. It's not the wait time that's static —that's dependent on how long the previous query took— it's the interval that's static.
use Time::HiRes qw( time sleep ); # Add support for fractional times.
my $interval = (1 / $qpm) * 60 * 1; # In (fractional) seconds.
my $next_run = time;
while (1) {
my $wait = $next_run - time;
sleep($wait) if $wait > 0;
$next_run += $interval;
... do work ...
}