Okay.
Hello clunkers.
And welcome to this lecture.
This lecture is on elastic cash and this is the last database service we need to cover in this section
of the course before we move on to our summary.
And then we can move on and learn all about Route 53 and networking.
So what is elastic.
And we did cover this off in the database one to one lecture but basically it's a web service that makes
it easy to deploy operate and scale in-memory caching in the cloud and the service improves the performance
of Web applications by allowing you to retrieve information from fast managed in memory caches instead
of relying on slower disk space databases.
So what does that actually mean.
Well essentially if you go to let's say Amazon dot com and you've got you go into I don't know the technology
department and you see the 10 top most purchased items what essentially is happening there is the easy
two instances they aren't making those or those queries back to an Aurora database what they're actually
doing is they're making those queries back to Alaska cache an Alaska cache is storing those queries
in there and it helps take off some of the performance impact because you're not constantly querying
your main production database for the same queries.
So you're going to cache your most queried information in Alaska cache and Alaska cache as a supports
to open source caching engines.
So we've got mem cache D and we've got readies.
So what is the difference between them cache D and red.
So when should you use one over the other.
Well if you just want a really simple cache to offload your database then you definitely want to use
mem cache D.
It's able to scale horizontally and you get multi threaded performance.
If however you're going to need things like advanced data types if you're going to need ranking and
sorting Data's if you're going to need pub sub so publishing and subscribing capabilities if you need
multiple Availability Zones or persistence or you need the ability to do backup and restores then you're
going to use Redis.
So if you want multi AC backups and restores and it's more sort of advanced data types then you're going
to use red you just want something simple and easy to get started with.
Then you want mem cache D so go onto my exam tips just remember the main thing you need to really understand
going into the certified Solutions Architect associate exam is the use case for elastic cache.
So it's use to increase your database and web application performance and a common exam scenarios will
be hey your database is overloaded what two steps could you take to you know to make this database perform
better.
One is to add a reed replica and then point your reads to your read replicas and then the other is to
use elastic cash at the certified Solutions Architect associate level you're not really required to
know the difference between mem cash D and read us but you definitely need to know it going into the
certified Solutions Architect professional exam.
Just remember that red US is multi easy and you can do backups and restores all varieties so that is
it.
This lecture everyone if you have any questions please let me know.
If not feel free to move on to the next lecture where we're going to summarize everything we've learnt
in the databases section and then that is it for databases so if you got the time please join me in
the next lecture.
Thank you.