‫Okay, so we are in CloudWatch Alarms,
‫so let's go and create an alarm.
‫So first of all, I'm going to create an EC2 instance
‫very quickly, and we're going to create
‫an alarm on top of the CPU utilization.
‫So we're going ahead and create an EC2 instance of t2 micro.
‫I will go quickly to preview and launch and then say,
‫yes, I have this.
‫So we don't need to keep it or anything like this,
‫we just want the instance to be launched.
‫And the idea is that we want to create an alarm that
‫will terminate the instance, if the CPU goes to 100%,
‫so let's create this alarm.
‫So we need to select a metric.
‫And so for this, we need to choose a metric.
‫So we need to go and find our EC2 instance.
‫So this is our instance ID, right here, and search for it.
‫And I'm maybe a little bit too quick, okay.
‫So let's wait for the instance to be launched.
‫I will go into EC2 per instance metric,
‫and then I will wait for it to be populating.
‫So it took about five minutes for some metrics to appear
‫in that cloud dashboard for my instance.
‫So now I can probably refresh this page and I will get the
‫chance to find the metrics I'm looking for.
‫So let me select a metric and then paste the instance
‫in perfect, I have it,
‫and I will go and find the CPU utilization of my instance.
‫So this is this metric right here.
‫Okay, well, select this metric.
‫As you can see, we have
‫the eight here and then we can choose a way to
‫compute this metric, so average, sum, maximum, and so on.
‫The period we want to evaluate this alarm on.
‫So five minutes is good because this metric gets populated
‫every five minutes, if we don't enable detailed monitoring.
‫Now we get some conditions in terms of the threshold.
‫So is it Static or is it an Anomaly detection?
‫Is it a greater than, equal than, and so on.
‫So I will say for example,
‫if you're a greater than 95%
‫for a long time, so for,
‫and here you can say, three out of three.
‫So that means that for 15 minutes, you're stuck at 95%,
‫then probably something is up with this machine.
‫And so in that case, I could choose a notification.
‫I could choose a Auto Scaling action.
‫I could choose an EC2 action, or in a systems manager
‫action, but I'm going to choose an EC2 action.
‫Okay, and it will say, hey, if you are in alarm, okay,
‫then just terminate this instance because maybe I know that
‫my application sometimes has a huge failure and the CPU
‫installation will be at a 95% or a 100%
‫for a very long time, And the only way to resolve this
‫is to just terminate the instance.
‫So I will choose this, and then click on next,
‫and say terminate,
‫EC2 on high CPU.
‫Click on next to verify everything, and we're good to go.
‫So now this alarm obviously does have insufficient data,
‫so we need to wait 15 minutes for it to be okay,
‫and it's not going to be triggered unless we make it so.
‫So, we could go into the EC2 instance and launch a way
‫to get the CPU very high for 15 minutes,
‫but this would be a very, very long,
‫or we can use the API call name,
‫Set alarm state, to really see what would happen if this
‫alarm went into the breach phase.
‫So let's have a look.
‫This is the history of the alarm, okay.
‫And what I'm going to do is that I'm going to set the alarm
‫to say, so I type AWS CloudWatch, set alarm states,
‫and we'll look at the API reference.
‫And so we need to do set alarm state the alarm name and the
‫state value and the state reason.
‫So we'll do, in here.
‫So AWS CloudWatch set alarm states,
‫and then we need to set multiple parameters.
‫So the alarm name is going to be this one,
‫then the alarm,
‫so the states value
‫is going to be alarm.
‫And the state reason, is going to be testing.
‫We press enter, and now this alarm,
‫if we refer to this page is now in the alarm state,
‫as you can see, it says in alarm.
‫And so the action is, when in alarm terminate the instance.
‫And so if you look at the history,
‫it says that the alarm updated from OK, to in alarm and
‫then an action was made and it's, successfully
‫executed the action to terminate my EC2 instance.
‫So if I go into my EC2 instances here, and I refresh,
‫as we can see is shutting down and is being terminated
‫because while there was an alarm that was triggered on top
‫of this EC2 instance,
‫and we did set up the alarm to do this specific action.
‫So that's it, I hope you liked it.
‫I hope this makes sense to you.
‫And I will see you in the next lecture.