For instance, a model for the file could be: The idea of having that generic file is so that you can check the same on every client. +1 and if that seems like too much trouble you could always look at the Nagios config files to see what command and parameters need to be run. Please refer tohttp://tldp.org/LDP/abs/html/untyped.html, hi! These plugin states directly translate to service states. This way, the other applications on your Nagios server can report the status of the hosts. It is called NSCA (Nagios Service Check Acceptor). Having managed large Nagios installations for many years, assigning services to hostgroups is an anti pattern and can make things complicated fast if your environment gets big. ##### # # NAGIOS.CFG - Sample Main Config File for Nagios # # Read the documentation for more information on this configuration # file. The following line is commented out to make MySQL listens on all interfaces. Please note that this article is published by Xmodulo.com under a Creative Commons Attribution-ShareAlike 3.0 Unported License. On a finishing note, Nagios can monitor many other sectors of a network. The plugin returns a CRITICAL state if the service is not started. Method 2. I've deployed a new instance of Nagios on a fresh install of CentOS 7 via the EPEL repository. 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Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. if one of my checked systems goes down, and therefore fails a PING check, I do NOT need to be notified that a file system is unavailable, or that SSH is down, too. The check_init_service plugin does not support checking multiple services. The host or the services will be tested again and again till the time the status is permanent. So the Nagios Core version is 3.5.1. This should enable MySQL to listen on all interfaces, as well as accept incoming connections from user nagios at any host. rev2023.3.3.43278. The daemon will listen for connections from remote clients, perform some basic validation on the results being submitted, and then write the check results directly into the external command file (as described above). When max_check_attempts is executed and status of the host or service is still not OK, then hard state is used. Use Hiera. great! If youve installed Nagios from source, check_httpd command will be located in the /usr/local/nagios/libexec directory. Is there a proper earth ground point in this switch box? How to use it? In such cases, only reports regarding hard state changes are propagated across Nagios servers. First, the servers are defined in Nagios. On the client host that you want to use to connect to remote Docker daemon, generate SSH keys from your user account; ssh-keygen. Consider the following script (check_warnings.sh): Based on the information provided by the nagiostats tool, I assume everything is ok if there are five or less services in Warning state.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-medrectangle-4','ezslot_1',108,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-medrectangle-4-0');if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-medrectangle-4','ezslot_2',108,'0','1'])};__ez_fad_position('div-gpt-ad-howtoforge_com-medrectangle-4-0_1');.medrectangle-4-multi-108{border:none!important;display:block!important;float:none!important;line-height:0;margin-bottom:7px!important;margin-left:auto!important;margin-right:auto!important;margin-top:7px!important;max-width:100%!important;min-height:250px;padding:0;text-align:center!important}. When the service check has completed, the child process will inform the main Nagios process (its parent) of the check results. ##### # Sample object config file for Nagios # # Read the documentation for more information on this configuration file. This is where the location of Nagios log file, status.dat file, lock file and host and services state update interval is defined. In order to be able to submit passive check results, we need to configure Nagios to allow the sending of passive check results, and set the host objects to accept them. A command to submit passive checks is PROCESS_SERVICE_CHECK_RESULT (visit http://www.nagios.org/developerinfo/externalcommands/commandinfo.php?command_id=114). Unlike with active host checks, Nagios does not (by default) attempt to determine whether or host is DOWN or UNREACHABLE with passive checks. The performance of on-demand service checks can be significantly improved by implementing the use of cached checks, which allow Nagios to forgo executing a service check if it determines a relatively recent check result will do instead. On-demand checks are performed as part of the predictive service dependency check logic. Passive checks are initiated and performed by external applications/processes, Passive check results are submitted to Nagios for processing, Asynchronous in nature and cannot be monitored effectively by polling their status on a regularly scheduled basis, Located behind a firewall and cannot be checked actively from the monitoring host. For example . So I decided to use the second method. There are several different use cases covered in this KB article: The sections below provide examples of how to perform these checks using different methods. thanks! More information on how this works can be found here. This command accepts the host name, status code, and the textual output from a check. The above definitions add a host called ubuntu_host and defines the services which will run on this host. 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. In Nagios, 2 types of checks are performed on hosts and services . NPCA includes a service module that can check if a service is running. An external application checks the status on hosts/services and writes the result to External Command File. The script should then post results to the Nagios daemon. 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. To figure this out I set nagios into debug mode with the configuration like this. Another example is where an application already processes information such as network bandwidth utilization. The following file can be modified to do the job. can nagios adjust its check time based on the status info? 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. The next time Nagios reads the external command file it will place the results of all passive checks into a queue for later processing. If a service is set up with a max_check_attempts directive of 5, then the same number of passive check results would need to be passed in order for Nagios to treat the new status as a hard state change. i.e: Check whether a document is older than x seconds. @sunardo I just ran into this exact same thing. No paper. You might also want to give the 'capture' plugin a try. will hold the return value of commands between $( ). Another difference is that active checks require much less effort to be set up when compared to passive checks. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? Services that are checked can be in one of four different states: Service checks are performed by plugins, which can return a state of OK, WARNING, UNKNOWN, or CRITICAL. Nevertheless, in response to your comment, I don't think there's an error in that, as Bash variables are untyped. Kaydolmak ve ilere teklif vermek cretsizdir. On-demand as needed for predictive service dependency checks. Service status codes are the same as those for active checks0 for OK, 1 for WARNING, 2 for CRITICAL, and 3 for an UNKNOWN state. The following diagram shows how both active and passive checks are performed by Nagios. Once the host and services are configured on Nagios, checks are used to see if the hosts and services are working as they are supposed to or not. In order to allow remote hosts to send passive check results to the monitoring host, I've developed the NSCA addon. Also, MySQL would not let just any host to connect to it. How can we prove that the supernatural or paranormal doesn't exist? You can tell Nagios to translate DOWN/UNREACHABLE passive check result states to their "proper" state by using the translate_passive_host_checks variable. How to Install Nagios? These checks are useful when you cannot monitor hosts/services on a regular basis. For this reason, the only way to perform such a check is to schedule them from the systemfor example, using the cron daemon (visit http://man.linuxquestions.org/index.php?query=cron). It essentially does the same thing as a debug level of 2048, but can be used on a per-plugin basis. In addition, it is run on the Linux operating system, precisely for the purpose of monitoring devices that are executed on Windows, Unix and Linux operating systems.Its main task is to constantly check key server resources, applications, networks and tasks. Nagios, the Nagios logo, and Nagios graphics are the servicemarks, trademarks, or registered trademarks owned by Nagios Enterprises. does the HTML display xx welcome xx? Line 1 ##### 2 # Sample object config file for Nagios : 3 # 4 # Read the documentation for more information on this configuration file. An external application checks the status of a host or service. When you restart the Nagios, this host will start getting monitored by Nagios and the specified services will run. sudo usermod -aG docker kifarunix. Nagios Enterprises makes no claims or warranties as to the fitness of any file or information on this website, for any purpose whatsoever. can anyone help me out for this problem:-, Check-Website-Response This mechanism includes password protection, along with encryption, to prevent injection of false results in to Nagios. The following is a sample script that will accept the host name, status code, and output from a check and will submit these to Nagios: As an example of the use of this script, the command that is sent to Nagios for host01, status code 2 (UNREACHABLE) and output router 192.168.1.2 down would be as follows: When submitting results, it is worth noting that Nagios might take some time to process them, depending on the intervals between Nagios checks of the external command pipe. No software installation. Nagios will still handle all notifications, event handlers, and dependencies between hosts and services. Difficulties with estimation of epsilon-delta limit proof, The difference between the phonemes /p/ and /b/ in Japanese. How can I make Status Information for Nagios services easier to read? To do this: Navigate to Configuration > Command > New. The default FQDN used for testing is www.google.com, but it can be changed as needed. In cases where the checks require the deployment of long-running processes or monitoring information constantly, this should be done as a passive service. Check WMI Plus allows you to check multiple services, here is an example that checks for two services that are running. 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. Nagios also supports a way to monitor hosts and services passively instead of actively. Once again, we are dealing with open source software, and Nagios purpose is aimed at monitoring computer systems. Securely download your document with other editable templates, any time, with PDFfiller. Set enable_notifications=0 in nagios.cfg. You never know how many (if any) traps or alerts you'll receive in a given time frame, so it's not feasible to just monitor their status every few minutes. . Or you can create a custom variable to store the port number , with your example: This is very important in situations where a host behind a router is reported to be down because the router is actually down. Nonetheless, they can be tuned to match the requirements. Nagios also offers a tool for sending passive check results for hosts and services over a network. Add additional tags that should be sent in the HTTP header. In such cases, Nagios decides when a check is to be performed, runs the check and stores the result. The following figure shows soft states and hard states. For Nagios to perform active checks when there is no up-to-date result from passive checks, you need to set the check_freshness directive to 1 and set freshness_threshold to the time period after which a check should be performed. When services change state too frequently they are considered to be "flapping". It is vital to make sure only legitimate networks have access to the database. By default you do not need to change any of the lines in this file and . For example, a plugin which returns a WARNING state will cause a service to have a WARNING state. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Thanks for contributing an answer to Server Fault! Hi, thanks for your comment. Checking a service using SNMP is not very straight forward, checking a process is the best solution here, please refer to the Process Checks KB article. Connect and share knowledge within a single location that is structured and easy to search. Nagios can monitor different mail server components like SMTP, POP, IMAP and mailq. Furthermore , Nagios can also check whether TCP port 80 (web server) is reachable e.g., the server is online but Apache/IIS is not responding. The results are passed to Nagios in the same way as they are passed for hosts. mark separates the command from the arguments in the check_command entry. Nagios can monitor DNS service by asking the DNS server to either resolve a specific fully qualified domain name (FQDN), or by asking the server to use the dig tool. Like every Nagios plugin, you will want to check from the command line before adding it to the configuration files. Each of these options opens the Manage Service Template screen.The New option will have no pre-selected directive values, Copy lets you create a new template based on an existing templates properties, and Modify enables the editing of an . How to handle a hobby that makes income in US. 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. When it comes in as a passive check, no state translation is done and Nagios stores the host and all child nodes being down. The check logic inside Nagios process starts the Active check. Next, update the remote Docker daemon DNS details on your hosts file if there is no local DNS; sudo tee -a "192.168.59.48 docker01.kifarunix.com docker01" >> /etc/hosts. Define the checks on /etc/nagios/nrpe_local.cfg. More information on the NSCA addon can be found here. just because i had already looked in the commands.cfg file to figure out which commands were running, but i wanted to know what flags were being set. The following is a script that runs the dd system command (visit http://man.linuxquestions.org/index.php?query=dd) to read an entire block device. Minimum number of days a SSL certiface must be valid. Nagios also offers a way of combining the benefits of both active and passive checks. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? A major difference between hosts and services is that service checks differentiate between soft and hard states. As an example of the use of this script, the command that is sent to Nagios for host01, service PING, status code 0 (OK) and output RTT=57 ms is as follows: A very common scenario for using passive checks is a check that takes a very long time to complete. Check WMI Plus includes a service module that can check if a service is stopped. Xmodulo 2021 About Write for Us Feed Powered by DigitalOcean, Creative Commons Attribution-ShareAlike 3.0 Unported License, Monitor whether MySQL is running by checking port, Monitor the availability of certain database. The figure shown below shows a passive check . By using this website, you agree with our Cookies Policy. Nagios can detect when services start flapping, and can suppress notifications until flapping stops and the service's state stabilizes. this is THE MOST comprehensive and straight forward turorial I've seen. Try to put full path in the command line. notifications_enabled 0 Here is another example to check CPU: nagios will indicate warning if the % cpu utilized by any process is greater than 70% and will indicate critical alert if the % cpu is greater that 80%
