Should you turn a Blind Eye to known activity?

The concept of a RAG status when monitoring systems and performance is well understood. As the analyst responsible for the system, you set a threshold against a performance metric; be it CPU utilisation, memory, file system, or anything else that seems particularly interesting or pertinent to you. You then sit back and wait for the . . . → Read More: Should you turn a Blind Eye to known activity?

Queuing Theory with Excel - extra

Only a few days ago, I blithly said

The Excel formula of 1/(Poisson(,,false)*exp()/() + Poisson(,,true)*exp() - Poisson(,,false)*exp())

Is equal to

Now you have the "tricky" value, all other values in the M/M/c queuing theory are MUCH easier to calculate.

It has been suggested to me, that it might help if I made this . . . → Read More: Queuing Theory with Excel - extra

Queuing Theory with Excel pt2

The previous blog post showed the formulas that are used in M/M/c queuing models, and finished by showing that we need an Excel formula for if we are going to use Excel to help us.

The previous blog entry also introduced us to = the number of servers, and = the average utilisation

Excel does . . . → Read More: Queuing Theory with Excel pt2

Queuing Theory with Excel pt1

Capacity Planning makes extensive use of Queuing theory to predict future response times of a system when the workload increases.  There are many tools available that will automatically calculate the queues and can do multi-variate planning. However, if you have a really simple system and no money to buy a dedicated toolset, what can you . . . → Read More: Queuing Theory with Excel pt1

Does the 'Cloud' negate the need for Capacity Management?

Capacity planning is the thing that stands out as the biggest advantage of the Microsoft cloud model. The Windows Azure platform takes that out of the equation for us, unlike the other cloud providers. Jonathan Malek Chief Architect and Director of Research, Associated Press

The above quotation is taken from a Microsoft case study . . . → Read More: Does the 'Cloud' negate the need for Capacity Management?

How big should your Capacity team be?

It sounds like the start of a particularly poor joke, but IS there an optimum size for a Capacity Planning team?

This might come down to the heart of the issue for many Capacity experts. Do you want your team to be 100% occupied, or do you want them to be 80% (for the sake . . . → Read More: How big should your Capacity team be?

Can Tools ever replace Analysts?

Over the years, the quality of tools available to the Capacity Manager have improved immensely. Little's Law may have been written before the advent of mass computing, but its application is crucial to predicting computing capacity. One of the earlier applications of the Law was to predict queuing on telephone exchanges. Whilst I am too . . . → Read More: Can Tools ever replace Analysts?

Better than average?

How busy is a system?

If one could measure a system at the most detailed level, then a system would either be busy doing "something" or it would be idle doing "nothing". Curiously enough, moving from this fact to the reporting of system utilisation is beyond some of the people that I have met over . . . → Read More: Better than average?

Should you ever replace a planning assumption?

In the planning cycle, you start off with a load of assumptions.

Then observations are made of existing systems, and you might be tempted to say that your assumptions were wrong... but are they?

Does experience of system A automatically mean that the assumption for system B is wrong?

Alternatively, you might have made an . . . → Read More: Should you ever replace a planning assumption?

Take That “Flood” the system… is this “Progress”?

Last Friday saw the release of tickets for the “Progress” tour by Take That. In every previous release of tickets for every previous major event, be it sporting or music, the ticket websites and phone lines have failed to cope with the Demand.

Last Friday was no different.

I tweeted (@jamescollings) at 7:40am that morning . . . → Read More: Take That “Flood” the system… is this “Progress”?