What to measure about performance

People usually think about performance wrong, resulting in asking wrong questions like can your server handle 10K connections or 2000000 users?.

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What is important to remember: Performance is a multidimensional characteristics. its impossible to make a picture of the system performance using only 1 metric.

When you asked about how good some stream of something is performing, you should think about:

• Throughput, Bandwidth
• Latency
• Response time
• Footprint

The relation between throughput and latency is described by Little’s law.