Okay.
Hello bloggers and welcome to this lecture.
And so we are going to summarize everything that we've learnt in the high availability architecture.
You've done really really really well to get through this section of the course.
It is one of the most challenging the only one that's more challenging is the surplus one which is coming
up.
So what do we learn in this section of course where we learn there's three different types of load balances
if you remember the car's example so we have our application load balancers there layer seven aware
and they're pretty much what you typically would want to use in production because they can make intelligent
rooting decisions and then have our network load balancers so just remember the Tesla Roadster.
This is where you need extreme performance or perhaps a static IP address network load balances not
application layer 7 aware that they only go up to layer for.
We then have our classic load balances these are basically where you want to keep costs under control.
You don't need intelligent rooting and you just want to keep your costs down.
So we have the three different types of load balances remember what they are and their use cases going
into the exam.
Now in the lab when we were rebooting our ideas for instance it caused our site to go down and we got
a 5 0 4 error and this mean that the Gateway has timed out so our whole web application is not working
and it could either be our web servers or our database servers in our lab.
It was our database server that stopped working.
So just remember that a 5 0 4 error means that the gateways timed out you need to figure out what's
going on with the application is this the web server layer the application layer if you've got one or
database server layer.
Moving on we learned about with classic load balances if you need the APB for off your end users you
need to look for the X forwarded for header we then also learn that instances are monitored by Elastic
Load balances are always reported as either in service or out of service and you can put health checks
which check the instances health by talking to it.
So we did that with the healthy dot reached CML file and then low balances always have their own DNS
names you were never given an IP address and by that I'm just talking about application load balancers
as well as classic load balances you can get a static IP address for network load balancer I would recommend
that you go and read the Elastic Load balancers F.A. Q I see in the Slide 4 classic load balancers I'd
read the FAA Q For all load balancers you're going to get about 10 questions on your exam concerning
load balances and a lot of them are just going to be scenario based questions as to which one you should
choose you might get a question about Gateway timeouts if you've got a 5 0 4 error and you might get
some questions on you know using a classic load balancer how you get a public IP address do you remember
it's using the x forwarded for header and then if you want a deep dive on application load balances
I appreciate we just went over it in a very sort of high level and we definitely have a deep dive course
on the cloud platform showing you how to create super intelligent rooting decisions but then went on
to learn about advance load balance a theory so we looked at Sticky sessions which enable your users
to stick to the same easy to instance and this can be really useful if you're storing information locally
to that instance.
We also looked an exam scenario where essentially we weren't getting connections to another easy to
instance and the way to enable that was to disable sticky sessions so sticky sessions can come up in
either sort of scenario.
We then looked across our in load balancing this enables you to load balance your traffic across multiple
Availability Zones and we looked at a scenario where essentially we're having issues where you know
traffic wasn't being routed to a particular instance in another availability zone and that was because
we didn't enable cross zone load balancing and then we looked at Path patterns and this allows you to
direct traffic to different easy to instances based on the U.R.L. contained in the request and we looked
at my view our outcome was going to our Web servers or my U.R.L. dot com was forward slash images was
going to our media based servers which were in a separate availability zone and then we looked at cloud
formation club formation is a way of completely scripting your cloud environment and then we also looked
at quick start which is a bunch of cloud formation templates already built by AWP solutions architects
allowing you to create complex environments very very quickly and then finally we looked at Elastic
Beanstalk with Elastic Beanstalk you can quickly deploy and manage applications in the adobe US cloud
without having to worry about the infrastructure that runs those applications you Simply upload your
application an elastic beanstalk automatically handles the details of capacity provisioning load balancing
scaling and application health monitoring and using an example elastic being really is aimed at developers
who just want to get their stuff into the adobe US cloud quickly they don't want to have to go and learn
something like cloud formation pulp formation is a way more powerful than Elastic Beanstalk but again
it takes an awful lot to learn it if you do want to learn information.
Of course we have an advanced cloud formation course on the a cloud guru so that is it for this section
of the course in the next section of the course we're going to look at applications on AWB as it's mostly
going to be theory.
We're not really going to go into a lot of labs on that because you don't need to you just need to understand
the theory in order for you to pass your exam and then we're going to go onto the funnest part of the
course which is service and then we're done.
So you almost at the end of the course.
Just two more sections to go.
Do you have any questions please let me know if not feel free to move on to the next lecture.
Thank you.