Numbers To Know medium
What is the typical Round Trip Time (RTT) between two servers in the *same* datacenter?
- A approximately 5 ms
- B approximately 500 microseconds (0.5 ms)
- C approximately 10 microseconds
- D approximately 20 ms
Answer: B. approximately 500 microseconds (0.5 ms)
In a modern cloud datacenter (like an AWS Availability Zone), communication between two servers is incredibly optimized, typically resulting in a Round Trip Time (RTT) of about 0.5 milliseconds (500 $\mu$s). This speed allows for distributed systems to operate almost as if they were a single machine. For contrast, if those servers were in different regions (e.g., US-East and US-West), the physical distance would force the RTT up to 60-100ms. Understanding this 'intra-zone' constant is vital for building low-latency microservices that must frequently talk to each other to fulfill a single user request.
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