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AndyHughes's avatar
AndyHughes
Regular Contributor
15 years ago

Fixed Load - what is this specifically?

Am I right in thinking that fixed load is the generator which attempt to keep the load at a fixed rate so for example 20 requests/sec. So depending on the interval the generator will 'top up' the level of requests to 20, each interval, however many are needed?
So in order to achieve an almost constant rate it would be best to reduce the interval to a minimum so that as soon as 20 dropped to 19 it was 'topped up' immediately because the interval is so small?

2 Replies

  • AndyHughes's avatar
    AndyHughes
    Regular Contributor
    15 years ago
    Based on some testing I have done, I don't think this is the case. In another of my posts I was getting 'out of memory' errors using a fixed load of 4 but with an interval of 10ms. Based on how I understood this to work, that would equate to an absolute maximum of 400 requests per second (100 blocks of 4 requests), but when I did a similar test at a load of 100 with a 100ms interval (which equates to a maximum of 1000 requests per second) there was no problem.

    I think its linked to the number of requests 'running' in the soapUI runner. This climbs hugely as you reduce the interval. What does this represent? I thought the load was supposed to be 'fixed'????? There should only ever be running, the number that you have selected as the load level???? Or am I missing something?
  • AndyHughes's avatar
    AndyHughes
    Regular Contributor
    15 years ago
    Ah. I believe I have realised the error of my ways. The requests are always singular and committed per interval until the number running reaches your target load, at which point the load stops and is maintained at that level. So reducing the interval ramps up the load. LOADUI does however, still die after a few hundred concurrent requests are running. But with no indication of excess RAM or CPU being used.