Welcome back to the Checkmk channel and in this episode, we're taking a look at parents and network topology.
|[0:00:16]||Today's subjects are the parents and a network topology. And I'll show you how you can use them to prevent unnecessary notifications.|
|[0:00:24]||Once again we'll be using our test system for this video. So once again we're back in our small distributed setup. We have a total of 10 hosts. Let's quickly go to Monitor and All hosts.|
|[0:00:38]||So we have four database servers. We have two Checkmk servers. We got a web server and three switches. Now let's go to Monitor and then Network topology.And here we have this cloud-like diagram.|
|[0:00:56]||Each of our Checkmk sites are depicted by this purple node. And then all the nodes around it, these are the hosts that are being monitored by that site.|
|[0:01:10]||All the green notes, these are hosts which are up, which currently don't have a problem. Then there is this red host which is down. But other than that, this whole thing doesn't tell me a lot. So now let's create a more interesting topology and talk about why we will do this.|
|[0:01:31]||Besides our database servers or web server and Checkmk servers, we also have three switches. And now let's assume that these four database servers are only accessible via switch1. Then what would happen if that switch were to go down?|
|[0:01:49]||Well, then our four database servers would no longer be accessible for a monitoring system and would also get the status 'Down'. And that will result in a lot of notifications, not only for the switch but also for the database servers.|
|[0:02:06]||It would be more useful to receive a notification regarding the issue of the switch, including the information that the database servers downstream are no longer accessible for the monitoring system. And for this, there is a status in Checkmk called unreachable.|
|[0:02:21]||And if that's the case, then you will normally not receive any notifications regarding the database servers because you already received one for the switch.|
|[0:02:30]||And it could be the case that the database server is working perfectly fine and even accessible for the users just not for the monitoring system. And to make this work, we need to configure in Checkmk, that the database servers are being accessed over the switch. And for that, there is a property called Parents. So, now let's go ahead and edit one of our hosts.|
|[0:02:56]||As always go to Setup and then Hosts and then to the Munich folder, Servers, and let's edit db-2-server.|
|[0:03:11]||Now there is this property called Parents. Let's check the box and now we can select the parent host and we'll pick 'switch1'. Now let's simply save and then activate our changes. And if we now head back to our Network topology, Monitor and then Network topology, you see that it's still the same diagram.|
|[0:03:44]||And in order to see the children we have to increase the number of hops. So now you see that db-server-2 is connected to switch 1. And the direction of the lines indicates in which direction the data is flowing.|
|[0:04:03]||You see here, it goes from db-server-2 to switch1 and then to the monitoring site. And now Checkmk knows that in order to reach a database server it needs to go through this switch. So when a switch would go down, it knows that it should not be able to reach the database server. And now let's do the same for all other database servers. Let's head back to the host configuration.|
|[0:04:35]||First, we will remove the parent from db-server-2. Save. And now instead of setting the parent explicitly on all servers we can also go back to Munich here and then edit the folder Servers. So now let's set the Parents on the folder level, switch1, again Save & activate the changes.|
|[0:05:16]||And now let's go back to our Network topology. Increase the number of hops again. And now you see that every single host in that folder is connected to switch1. Whenever we add a new host to that folder, it will automatically or Checkmk will automatically know that it's only accessible over switch 1.|
|[0:05:48]||And next thing we should do is try if this actually works. And how can we do that? Well, switch1 has to go down so then we can see what would happen. But because this is a test system, I cannot simply turn off the switch. We have to do a little trick.|
|[0:06:11]||If we right click on the host and then go to details of host and then edit the host property so click on the host name, then Hosts configuration. Instead of turning off the switch we will simply change the IP address a little. Activate changes.|
|[0:06:44]||Now our host or Checkmk should assume that our host is down. Increase the number of hops, now you see switch 1 is down. You also see that db-server-1 is now unreachable. It was previously down but now Checkmk assumes that it's down, likely because of the fact that switch 1 is down.|
|[0:07:10]||You might ask yourself why the other three database servers did not go to the unreachable state. Normally in a real system they probably would but because this is a test system and Checkmk is still able to ping these hosts, they will remain up.|
|[0:07:27]||So that means if Checkmk is still able to reach the host even though that the parent is down. They will remain up and Checkmk will keep monitoring them as usual.|
|[0:07:42]||But what if you have a system with redundant switches? If the hosts were accessible over more than one switch, well, then as long as one of the switches is functional, then the host behind it should still be accessible.|
|[0:07:56]||And in that case, you won't have a tree structure but a meshed structure and you can also configure this in Checkmk. So once again let's go to the host configuration. Setup --> Hosts. And let's go back to the folder we were editing.|
|[0:08:12]||And you might have seen this already before, here at the Parents you can select multiple parents. So let's add one, let's add switch2. Once again, save and activate. Now let's head back to the Network topology. Increase the number of hops.|
|[0:08:42]||And you see that it became a bit more cluttered and that's because all these servers are now connected to both switch1 and to switch2. So switch2 and switch1 are connected to the site and all other servers are connected to these switches.|
|[0:09:00]||And you'll also see that now db-server-1 is no longer unreachable but down. Because Checkmk sees that it should be accessible over switch1 and switch2 and one of them is functional, so it knows that the problem lies with the host itself with db-server-1 and not with the switch.|
|[0:09:25]||As you can see you have the ability in Checkmk to map your network topology primarily to avoid unnecessary alerts. And when we talk about network topology in Checkmk then we mean the topology from the point of view of the monitoring system.|
|[0:09:40]||So how Checkmk reaches the hosts and not your network topology in general. And if you have a distributed setup, then every site has its own topology and that's because the monitoring takes place locally from the site.|
|[0:09:56]||If you configure your network topology and Checkmk correctly, you can avoid a lot of unnecessary alerts. And this is absolutely recommended, especially if you have a few sites with a large amount of hosts that are only accessible over a few routers or switches.|
|[0:10:14]||So that was it again for this episode about network topology. I hope it was helpful to you. If so, subscribe to our channel and like the video. See you next time.|
Ep. 1: Installing Checkmk 2.0 and monitoring your first host
In this video, Baris explains how to take get started with Checkmk and start monitoring your first host within a few minutes.
Ep. 2: The Checkmk 2.0 user interface
In this video, Baris take you through the new user interface in Checkmk 2.0. He explains the various components of the User interface such as the new navigation menus, the Sidebar, main dashboard, tactical overview, how to switch between the Checkmk interface themes and much more
Ep. 3: Using SNMP to monitor network devices in Checkmk 2.0
In this episode, Baris explains how to monitor network devices with Checkmk. SNMP is a protocol that many switches, routers, printers, UPSs, hardware sensors and other devices have implemented with the purpose of being able to monitor them easily.
Ep. 4: Monitoring Windows in Checkmk
In this video of our Getting started with Checkmk series, Baris explains how to install a Checkmk agent on a Windows host system and add that into your monitoring environment.
Ep. 5: Using metrics and graphs in Checkmk 2.0
In the 5th episode of the Getting started with Checkmk series, Baris explains using various metrics that you can monitor in Checkmk such as CPU utilization, CPU load etc. You can also see graph visualizations for these metrics or create and customize your own as per your requirements.
Ep. 6: Updating Checkmk 2.0 and using multiple instances
In this video, Baris explains how to update your Checkmk instance. It is very easy and can be done within minutes. You can run multiple Checkmk instances with different versions on the same system. This gives you the flexibility to test the new version before using it in production.
Ep. 7 (part 1): Working with rules and setting thresholds in Checkmk
In the following three-part videos series, Baris explains rule-based monitoring with Checkmk. In the first part, he shows you how you can work with rules and set threshold values. Rule-based configuration is one of the key features for Checkmk which helps you to scale your monitoring easily within minutes.
Ep. 7 (part 2): Smart rules with Host Tags in Checkmk
In the second part of this video, Baris explains using Smart rules with host tags in Checkmk. In the first part, he shows you how you can work with rules and set threshold values. These are features that you can use to build your rules even more intelligently and to better organize your monitoring.
Ep. 7 (part 3): Managing Hosts in Folder in Checkmk
In this final part of our episode on Rule-based monitoring in Checkmk, Baris demonstrates how to manage hosts in folders in Checkmk. This helps you to apply your monitoring configurations at scale and organize your hosts according to your needs.
Ep. 8: Working with Host and Service Groups in Checkmk
In this Baris demonstrates how to create host and service groups in Checkmk, so you can perform actions on an entire group instead of configuring each of them individually.
Ep. 9: Using the Quicksearch function in Checkmk
In this episode of the Checkmk tutorials, Baris shows how you can use the Quicksearch function in Checkmk. You can use it to easily find and manage certain hosts or services. He also explains some examples of filters to you. In Checkmk 2.0 you can use the same syntax in the Seach function found in the monitor menu to get identical results.
Ep. 10: Detecting configuration errors with the Analyze Configuration feature
With the Analyze Configuration feature, you can check if there are any configuration errors in your installation. Checkmk controls a number of possible security risks or potential performance restrictions and indicates if there are any problems.
Ep. 11: View creation and customization in Checkmk
In this video, Baris demonstrates how to customize headers, columns, and more in Views in Checkmk for yourself or other users. He also explains how to create custom views and add desired information to these views.
Ep. 12: Acknowledging problems in Checkmk
In this video, Baris explains how you can acknowledge problems in Checkmk. This function helps you to qualify the states of hosts and services. This allows you to keep track of messages in the main dashboard and, for example, you can add comments to problems.
Ep. 13: Scheduling downtimes in Checkmk
In the episode of our Getting started with Checkmk series, Baris explains how you can manage the maintenance times of your systems in Checkmk. Such scheduled downtimes prevent your monitoring from sending false alarms when a host or service goes to WARN or CRIT during maintenance work. You can also inform the users concerned about the maintenance via Checkmk.
Ep. 14: Distributed monitoring with Checkmk
In this video, Baris explains how you can connect several Checkmk instances to a monitoring system and then manage it.
Ep. 15: MKPs and Plugins in Checkmk
In the 15th episode of our Getting started with Checkmk tutorial series, Baris explains what are Checkmk Extension Packages (MKPs) and how easy it is to integrate them into your Checkmk monitoring environment. MKPs are the preferred format when you make your own extensions as it makes it easy to share with other users or deploy in distributed environments.
Ep. 16: Working with 'Bulk Actions' in Checkmk
In this episode of our Checkmk tutorials series, Baris explains how you can save a lot of time with bulk actions. With this feature you can perform various tasks such as deleting, renaming, service discovery etc. on a large number of hosts simultaneously.
Ep. 18: Creating and customizing dashboards in Checkmk
In this video of our Getting started with Checkmk series, Mathias explains how you can create and customize dashboards in Checkmk 2.0, so you can get insights into your monitoring according to your requirements. Find out more in this video.
Ep. 19: Monitoring websites and their certificates with Checkmk
In this episode, Bastian demonstrates how to monitor a website and its certificate with Checkmk. You can also monitor specific web pages with Checkmk by using the several options that will suit your use case. Learn more in this video.
Ep. 20: Configuring dashboard elements in Checkmk
Learn how to add data visualization elements of the various metrics into your Checkmk Dashboard. In this video, Mathias explains how you can configure these elements and create a dashboard as per your requirements.
Ep. 21: Setting up notifications in Checkmk
Learn how to set up notifications in Checkmk and assign relevant contacts and contact groups to be notified for various events. Later in this video, our presenter Bastian also demonstrates how you can set up rule-based notifications according to different conditions for hosts and services.
Ep. 22: Monitoring logfiles with Checkmk
Monitor your logfiles with Checkmk using its Logwatch plugin. It is very useful when you want to monitor your logfiles regardless of whether you are using a UNIX/Linux or a windows based system. Learn more in this video.
Ep. 24: 3 Rules for efficient network monitoring
In this video, Bastian demonstrates 3 rules that will help you to efficiently monitor your network interfaces. With Checkmk 2.0, with just three rules, you can set up an efficient network monitoring that will not only monitor all of your network interfaces but also simultaneously provide a detailed overview of all of your ports.
Ep. 25: New UX and security improvements in Checkmk 2.1
Checkmk 2.1 come with many UX improvements such as pre-built dashboards for Linux and Windows, faster core performance and much more. Security features such as two-factor authentication etc. were also added in this new version. Watch this video to learn how to use these new features and enhancements in Checkmk.
Ep. 28: Working with InfluxDB integration in Checkmk
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Ep. 29: New agent architecture in Checkmk 2.1
With Checkmk 2.1, the agent architecture was modified to enable performance improvements and add new features such as TLS encryption, data compression, and the reversal of direction of communication from the agent. This will enable push mode and pull mode.
Ep. 30: Clustering the Checkmk appliance
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Ep. 32: Working with the Agent bakery in Checkmk
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Ep 33: Monitoring Docker containers with Checkmk
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Ep 34: Introduction to Checkmk Ansible collection
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Ep 35: Monitoring SQL databases with Checkmk
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Ep. 36: Introduction to different types of checks for monitoring with Checkmk
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Ep. 43: Working with Hardware/Software inventory in Checkmk
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