In such a case, adding a module that reports current utilization along with the OK/WARNING/CRITICAL state to Nagios seems much easier than using active checks for the same job. As with submitting host check results, it is worth mentioning that Nagios will take some time to process passive check results as they are polled periodically from the external commands pipe. The __HOST__ is a special service name, which represents the host check in Nagios. The line should look like: Define the standard checks that you will perform on every client with NRPE. Here is the output when the RemoteAccess service was started: Checking if a service is stopped using SNMP is not very straight forward, checking a process is the best solution here, please refer to the Process Checks KB article. The files and information on this site are the property of their respective owner(s). 2. The host status code should be 0 for an UP state, 1 for DOWN and 2 for an UNREACHABLE state. Nagios comes with a wide range of built-in scripts for monitoring services. Start Nagios Daemon Using nagios -d Typically you would execute "service nagios start" to start the Nagios daemon, which really calls the /etc/rc.d/init.d/nagios script. Add the file to the standard Nagios Core location, /usr/local/nagios/libexec. However, in a big environment it is very likely to need some custom checks for specific uses, for instance: Checking on a certain task result, monitoring an in-house developed application, among others. Just cd (or not) into the plugins directory (this directory location varies, depending on how you've installed it, but check /usr/local/nagios, or /usr/lib/nagios). hello.. For example, you can use the 'check_http' plugin to verify that a web server is running, is returning the right text, or has an up-to-date SSL certificate. Nagios Plugins Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. Be aware that the service module is cAsE SeNsative, you can overcome this with the match= argument. The plugin returns a CRITICAL state if the service is not started. These plugin states directly translate to service states. Yeah, it's totally brute-force, but it works for me. Passive checks require all the logic related to what should be reported and when it should be checked to be put in an external application. This setting is done on all MySQL servers. (1 + 2 + + 2048), Also note that your debug file will grow quickly and then rotate itself. It allows the implementation of plugins, developed by the community, or even allows us to configure our own monitoring scripts. I've deployed a new instance of Nagios on a fresh install of CentOS 7 via the EPEL repository. Periodically when these checks are processed, notifications or alerts are sent depending on the information in check result. # Plugin commands (service and host check commands) # Arguments are likely to change between different . When Nagios plans and receives results from active checks, it takes the actual network topology into consideration and performs a translation of the states based on this. There would be many cases when the failures will happen randomly and they are temporary; hence Nagios uses states to check the current status of a host or service. More information on the NSCA addon can be found here. In order to use them, the host needs to be configured to accept passive checks results. Each server runs one or more common services. For example, to set up a very similar service, all we need to do is to use the same parameters as those for the hosts: In this case, Nagios will never perform any active checks on its own and will only rely on the results that are passed to it. Nagios can check whether the server is online by running ping on the IP/name of the server as well as it can be set up to provide warnings in case the round trip time (RTT) to the server increases. i'm very new on that kind of progamming what does this line ", " means i really want to lear some but i need help please helpme. These types of checks are called Active Checks. Find the plugin you want to run (if you're not sure, compare what you see in your plugins directory on your Linux box with the plugins located here: http://exchange.nagios.org/directory/Plugins, or try running "./plugin-name -h" to get the help info about the plugin). See the HTML : 45 It looks like that with the default install, theres no configuration set up to tell Icinga where to look for the check_http executable. host_name Server01 Follow these steps to install the plugin: Download the plugin. check_http plugin is used to verify the status of HTTP server (or HTTPS) that is running on a remote host. These checks help ensure that the dependency logic is as accurate as possible. External applications can submit passive service check results to Nagios by writing a PROCESS_SERVICE_CHECK_RESULT external command to the external command file. This tutorial was tested using Nagios Core 4.3.4 on Debian 9.2if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-box-3','ezslot_3',106,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-box-3-0'); Even though Nagios Exchange has thousands of available plugins to freely download, sometimes the status needed to be checked is very specific for your scenario. Nagios server in this example is hosted on 192.168..150 and an example client is hosted on IP 192.168..200 Exit Codes To identify the status of a monitored service, Nagios runs a check plugin on it. If you would like to use the whole or any part of this article, you need to cite this web page at Xmodulo.com as the original source. Learn more. So I decided to use the second method. But if the monitoring application is not running or some other issue prevents it from reporting, Nagios can use active checks to keep the service status upto-date. # Defaults to 0, put to 1 for systemd. Check WMI Plus allows you to check multiple services, here is an example that checks for two services that are running. Add additional tags that should be sent in the HTTP header. Check HTTP Check whether Apache HTTP is running on a remote server using check_http. sudo usermod -aG docker kifarunix. As this tutorial is based on Debian 9, I will show as an example how to install it, but you can find instructions for any distribution. The example contains partial output. For example, if you are bringing down your HTTP server everyday sometime between midnight and 1:59 a.m, you can specify the above "247-except-night-12-2" timeperiod in your service definition for the check_period and notification_period as shown below for your particular service definition. The files and information on this site are the property of their respective owner(s). this is more along the lines of what i meant. The basic workings of service checks are described here Services are checked by the Nagios daemon: On-demand checks are performed as part of the predictive service dependency check logic. To identify the status of a monitored service, Nagios runs a check plugin on it. It shows what is performed by Nagios in both cases and what needs to be done by the check command or an external application for passive checks. How to tell which packages are held back due to phased updates. . . We can also do it at a contact level, by disabling notifications . Examples: CPU load, RAID status An snmp system is generally considered to have 3 components: Agents Agents expose management information on a device. nagiostats provides statistics of which only the part `Services Ok/Warn/Unk/Crit: 8 / 0 / 0 / 0` are interesting to us, so we are using grep to extract this line. With a little tweaking, Nagios can help monitor this application port as well. So in this blog post is all about how I used Hiera to manage the Dev,Test, Prod Stratos environments. To check whether a specific webpage is available, use the -u option as shown below. 5 check_http examples In this way, NSCA communication sent over the Internet is more secure. The object needs to have the passive_checks_enabled option set to 1 for Nagios to accept passive check results over the command pipe. In this example we are going to define a service and assign it to localhost, because this check is on Nagios itself. The external application writes the results of the check to the. Yup, just like any other linux flag, the "-" with whatever flags you use will load the flag. /usr/local/nagios/libexec/check_ping -H 192.168.1.2 -w 100.0,90% -c 200.0,60% .use: Get your subscription here. Why is there a voltage on my HDMI and coaxial cables? You can check tomcat server, or apache server, or glassfish, or any server that is running on a different port by speficying the port number as shown below. If youve installed Nagios from source, check_httpd command will be located in the /usr/local/nagios/libexec directory. These state changes result in different state types (HARD or SOFT), which can trigger event handlers to be run and notifications to be sent out. The following file can be modified to do the job. How can I make Status Information for Nagios services easier to read? You can define service execution dependencies that prevent Nagios from checking the status of a service depending on the state of one or more other services. When it comes to checking MySQL, it should be kept in mind that MySQL, by default, listens on only the loopback interface 127.0.0.1. A major difference between hosts and services is that service checks differentiate between soft and hard states. It allows to configure alerts and has different states for them. This plugin uses systemctl is-active command, please check you have systemd. You have entered an incorrect email address! Nagios check_udp_ports returning critical: result to scheduled check, runs fine manually, Nagios - check procs and --metric=elapsed on the same service. The same queue that is used for storing results from active checks is also used to store the results from passive checks. Enable and restart the nrpe service: [user@mon]# systemctl enable nrpe [user@mon]# systemctl restart nrpe. Nagios server in this example is hosted on 192.168..150 and an example client is hosted on IP 192.168..200 Exit Codes To identify the status of a monitored service, Nagios runs a check nagios.cfg. Learn more about Stack Overflow the company, and our products. It is possible to monitor machine metrics, such as disk usage, CPU use, and so on. Server Fault is a question and answer site for system and network administrators. $ check_http -H 192.168.1.50 HTTP OK HTTP/1.1 200 OK - 332 bytes in 0.004 seconds |time=0.004144s;;;0.000000 size=332B;;;0 2. In other cases, passive checks are the way to go. Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. command line output while running with -S is check_http: Invalid option SSL is not available, Next post: UNIX / Linux whatis Command Examples, Previous post: UNIX / Linux split Command Examples, Home | Linux 101 Hacks Table of Contents | Contact | Email | RSS | Copyright 20092022 Ramesh Natarajan All rights reserved | Terms of Service, host name of the server where HTTP (or HTTPS) daemon is running, Port number where HTTP server runs. Unlike active checks, Nagios will not take network topology into consideration by default. They have a lot of advantages and some disadvantages. Active checks reach out from the Nagios host and test if a service is doing what it's expected to do. Check whether Apache HTTPS is running on a remote server using check_http. On-demand service checks are also run in parallel if needed. The application can also periodically let Nagios know if it succeeded in using the database without problems. More information on how this works can be found here. Active checks are initiated by Nagios process and then run on a regular scheduled basis. Previous parts of this book often mentioned Nagios performing checks on various software and machines.