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Hey guys and welcome back. So now what I want to briefly talk to you about is the concept

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of being able to predict future resource needs. Now to begin, one of the first tools

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I want to talk to you about is something called collectD. Now what this is, is ultimately

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a daemon. And this daemon has the purpose of collecting system statistics. Now the way

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collectD actually does this is that it uses something called plugins. And these plugins

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actually determine what collectD will actually collect. Now one thing to note about the collectD

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is that there are some limitations here. This is not an all purpose tool. For example, the purpose

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is really limited to collecting. And I would tell if I could spell that correctly. Collecting data.

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That means that it's not going to display the data for you any nice graphical form or anything

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like that or analyze the data. Instead collectD is just going to like I say collect that data and

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you can then feed that data if you so wish into another program. Now collectD typically is not

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installed by default on most Linux systems. So we do actually have to run through the installation.

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So what I will say here on my Zubuntu machine, I can just use the app package manager and install

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collectD. Just type in my passwords and hit Y and enter. Okay, perfect. So now that we have collectD

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installed, let me just clear the screen. One of the things that we want to be aware of for the

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purposes of the examination is where we can actually configure the collectD daemon. Now we

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are going to be able to do this by modifying a file in a particular location. So let me show you what

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this location is. As if I go into the etsy directory and then go into collectD. If I do an ls, we should

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now see this collectD.conf file. Okay, so try to remember that path etsy collectD collectD.conf.

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If I go in and modify this, let's say nano for example and hit enter. This is the main configuration

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file. Now within here, we can do many cool things. We can actually determine how often we should be

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able to collect particular data. Say for example here, we can see we have this value here interval

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10. This means that every 10 seconds, we will have a new query collecting more data. Now this is the

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default value. If we want to happen to change this, we would uncomment this configuration by removing

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the what is now called the hashtag and we can see the color changed. If we could change this

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interval to maybe say every five seconds or every 15 seconds, however you choose. But for now, I'm

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actually not too bothered with this. So I'll just comment this out. So it's inactive and we'll still

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have the default of 10. Now if we scroll on down, another really important thing to notice is this

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plugin section right here. This is going to allow us to specify which features we actually want to

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collect information on. Now if you happen to scroll down, you'll notice that most of these plugins

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are commented out. The ones which are actually on by default are the battery, the CPU, the disk,

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entropy, interfaces, memory so on so forth. But the vast majority like I say are commented out. But

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if we wanted to decide that hey, we actually want to collect information on our network, we could go

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to the plugin network and we could just remove the hashtag to uncomment out this configuration.

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And this would allow us to activate this configuration. Say for example, I could just save this up and

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notice I should have pointed this out. This is a global configuration file within the Etsy directory.

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Therefore, I'm going to have to use super user privileges. So I would say sudo nano collectd.conf

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and scroll on down. Now I could remove and save the changes. And in order for these changes to

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take effect, we would actually have to reload the service. I could say sudo system ctl restart

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collectd.service. If I hit enter, that should now reload the service and the new configurations,

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i.e. the changes we have just made will take effect. We can actually use collectd to monitor our

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network statistics. So really for the purposes of the examination, understand what collectd does

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and what it does not do and really try to remember the location of the configuration file and understand

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that we have these concepts of plugins. And if we want to activate a particular plugin so that we

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can measure a particular resource such as a CPU or what is going on in our network, we can just

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simply uncomment that plugin so that it will be active after we reload the configuration file.

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Now another thing I want to just briefly touch upon is the subject of monitoring solutions.

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There are some solutions we have to have an awareness of, at least at a high level,

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for the purposes of the examination. But like I say, this is just a high level topic,

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meaning that you don't have to really concern yourself with how to configure these tools

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specifically, just more have an awareness of what they actually do. So the first monitoring solution

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I want to point out is one called Nagios or Nagios. I've heard it said both ways, I'm not quite sure

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the correct way. Now Nagios is ultimately a family of projects. So we could have a Nagios log server

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or a Nagios network analyzer or a Nagios incident manager, so on and so forth. Now the cool thing

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about Nagios is that it can provide a plugin to interact with collectd. We can actually use

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collectd-nagios and that can actually be used to query the collectd

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daemon for information. So the information that is collected by collectd, we can feed it into

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Nagios and use the Nagios network analyzer to analyze the network traffic or network statistics,

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should I say, that we have gathered using collectd. Now another solution we have is one called MRTG.

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This is the multi-router traffic grapher and this is really used to monitor network traffic loads.

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It basically reads information from your router and your logs and you can actually take this

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information and graph it. This can provide a nice visual interpretation of that information

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to make it much more digestible for you as a system administrator. Now another one we want to be

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aware of is one called cacti. This too, like MRTG, also focuses on network monitoring. Now this tool

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is basically a front-end interface for something called RRD tool. Now this stands for the round

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robin database tool. So simply put, information collected by the round robin database tool

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can be ingested by cacti and cacti will provide to you a nice easy interface so that you can

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display information or graph particular data received via this tool. Now the key thing to note

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about all of these types of tools is that we can take this information, monitor our data and we can

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use that information to observe and use for capacity planning. Say for example you happen to note

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on your graph you're having a very large and prolonged spike and maybe say network traffic.

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You might think hey but actually getting much more network use maybe it's now time to increase our

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bandwidth because if we keep following this trajectory of network use just getting higher and

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higher and higher suddenly we're going to get a bottleneck and the users are going to suffer

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and we definitely do not want that. So having this type of monitoring information allows us to plan

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ahead and we can see trends on the horizon as they're approaching. So really these tools all

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together is going to help you identify resource exhaustion and allow you to predict growth and

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even diagnose particular problems. If you happen to see a spike in some particular resource, CPU,

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maybe it is network traffic, you can then use that information to potentially identify a

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particular problem on your network. So the ability to collect data to be able to feed that data into

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a tool which can graph that data or analyze that data, this is obviously very valuable for anyone

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administering and managing the systems on our network. Now one thing to say about these tools

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just as a disclaimer is that there is no way you can get 100 accuracy with these tools. You might

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be able to graph a particular trend but there is no way for you to know that that trend is going to

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continue. Say for example you've got a nice graph which is showing a very steady rate of growth

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over a particular period of time. There is no way for you to know that suddenly you're going to

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encounter an abnormal spike. Okay so just be aware that these tools definitely have a use,

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they definitely provide valuable information but there are limitations to their abilities.

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Okay dogs, I hope this has been informative for you and I'd like to thank you for viewing.