Michael Schwartzkopff

A SNMP Agent for Pacemaker

The pacemaker program is the Cluster Resource Manager in Unix operation system cluster. It decides which resoure starts on what node in respect to the availability of nodes and the configuration constraints. Please see the pacemaker page for the description of the cluster software.

When you operate a cluster you want to know, what it's status is or get alerts if something happens. In short, enjoy all the benefits of a Network Monitoring System (NMS). The internet standard protocol for NMS to monitor devices and applications is the Simple Network Management Protocol (SNMP).

In this article I will describe, how you can set up a SNMP agent that publishes the state of your cluster nodes and resources. Every NMS (OpenNMS, Zabbix, nagios or the commercial alternatives) will be able to monitor the cluster properly.

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Monitoring Systems, SNMPv3 and the engineID

Sometimes encrypted SNMPv3 requests from Network Monitoring Systems (NMS) to devices just fail out of the blue. There is no reasonable explanation for the behaviour. In this article I will describe the problem, spectulate about the reason, and present a workaround (or solution, if you like). It works for me be I am not sure if I really found the real problem. At least it solves the problem which showes some real weired behaviour of the Zabbix server and the monitored device. But the problem not only occures in the Zabbix NMS but I also saw it in the CA's Spectrum system.

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OpenSSL Performance with a VIA Eden (padlock)

Encryption of Gigabit lines should not be a problem with recent CPUs. But how about low-cost embedded devices that do the encryption in silicon on the chip? To find out I bought an `Artigo A1200 <http://www.viaembedded.com/en/products/systems/1850/2/ARTiGO_A1200.html>`_ embedded system and installed Linux. As a first test I wantet to check the encryption speed with openssl. In this article I describe the installation and the results.

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Zertifikate überwachen mit Zabbix

Es ist sehr ärgerlich, wenn das Zertifikat einer Webseite abgelaufen ist. Große rote Warnlampen springen den Besucher der Seite an, sie sind verunsichert und können im schlimmsten Fall sogar die Seite meiden. Der Administrator versucht verzweifelt das Zertifikat zu erneuern, was er das letzte Mal von ca. zwei Jahren gemacht hat und natürlich nun, wenn er es braucht, vergessen hat. Das gleiche gilt natürlich auch für Mailserver, die TLS Verschlüsselung für SMTP oder IMAP anbieten.

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Postfix Deliverability Monitoring with Zabbix

Administrators operating a ``postfix`` mail server expect from a monitorng system not only an alert if the server is down. The monitoring system also should collect some important data to get an impression of the performance of the mail server. As a very simple approach I want to present a solution for the Zabbix system. It gathers the information about active and deferred mails from the postqueue command and the numbers of sent and bounced mails from the mai log file.

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Monitoring Certificates with Zabbix

There's nothing more embarrasing than running a public website with expired certificates. Huge red warning message pop-up all over the place, users are concerned and might even avoid your site. The admin frantically trying to find out how to renew the certificate, something they either never done before or forgot how to do it. The same applies to mail servers that offer TLS encryption for SMTP or IMAP.

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