With COVID-19 live data easily being available, this dashboard was relatively easy to put together using BigQuery and Data studio. I was most curious about correlation between countries which have more senior citizens and its death rate. More or less, there seems to be some correlation, but there are many other factors playing a role in a country's ability to bend the curve.
Large distributed systems run into a problem which smaller systems donâ€™t usually have to worry about. â€œ Brewers CAP Theorem â€ [ Ref 1 ] [ Ref 2 ] [ Ref 3 ] defines this problem in a very simple way. It states, that though its desirable to have Consistency, High-Availability and Partition-tolerance in every system, unfortunately no system can achieve all three at the same time . C onsistent : A fully Consistent system is one where the system can guarantee that once you store a state (lets say â€œx=yâ€) in the system, it will report the same state in every subsequent operation until the state is explicitly changed by something outside the system. [ Example 1 ] A single MySQL database instance is automatically fully consistent since there is only one node keeping the state. [ Example 2 ] If two MySQL servers are involved, and if the system is designed in such a way that all keys starting â€œaâ€ to â€œmâ€ is kept on server 1, and keys â€œnâ€ to â€œzâ€ are kept on server
Introduction Loadbalancing may mean many different things to different people but its all about distributing load. For me its an architecture of how some network services can be scaled by adding multiple servers performing the same tasks. If you had a popular website with static content, and if your server couldn't keep up with the request, all you had to do was setup multiple web servers and use round-robin DNS entries to divide the load into multiple servers. For dynamic web applications like search engines this plays a significant role because the number of users per node can support is much lower. Over time, as applications grew more complex and as web companies found customers outside US they found out the hardware that the only way to optimize network performance was by going local. Loadbalancing POP (points of presence) around the world provide a snappy user experience which has been important and drawing more customers. While, static content on web servers can easily be rep