Amazon ElastiCache vs. Azure SQL Database vs. django-mysql vs. memcached Comparison Chart

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You can think of it as a short-term memory for your applications. memcached allows you to take memory from parts of your system where you have more than you need and make it accessible to areas where you have less than you need. The first scenario illustrates the classic deployment strategy, however you'll find that it's both wasteful in the sense that the total cache size is a fraction of the actual capacity of your web farm, but also in the amount of effort required to keep the cache consistent across all of those nodes. With memcached, you can see that all of the servers are looking into the same virtual pool of memory. Also, as the demand for your application grows to the point where you need to have more servers, it generally also grows in terms of the data that must be regularly accessed. A deployment strategy where these two aspects of your system scale together just makes sense.