mBrace Performance Modelling - Data Gathering

Preparation

The measurements that are required, entail a collection of various metrics which are collected from a number of different sources.  In order to ensure that the relationships between the different measurements captured are maintained, all time clocks on the various application server and client components must be synchronised. The Network Time Protocol (NTP) can be used to effect such a synchronisation between servers and clients.  Should synchronisation not be practically possible, application components which cannot be synchronised should be explicitly and clearly identified, along with the time differences encountered (in 1 second increments).


Other preparation activities include the collection of information which will assist in the workload characterisation process.  This entails a list of the individual transactions which will be used by the application in a production environment.


Attention should be given to high impact transactions, namely transactions which have the following characteristics:

•    high response times

•    high server resource impact (transactions which effect data input)

•    high numbers of users executing specific transactions

•    high transaction execution rates with regards to specific times of the day


Capture engineers should also have an in-depth understanding of server component configurations (specific CPUs etc.) and geographic user distributions in the test and the production environments.