Part Two: Configuring a Central Syslog Server By Urbana Der Ga’had In Part 1 of this article we installed and configured LogSentry to automate the monitoring of the system logs on our machine. That’s great if we’ve only got one or two systems, but what if we have a dozen *nix systems, or fifty, or […]

One particularly useful tool for systems administration is top. One thing you may not be aware of, is that you can output the information top provides to a file. You may also not know that you can run commands like this remotely via ssh. Here is a short script that demonstrates this: #!/bin/sh /usr/bin/ssh user@domain.com […]

We have a process that creates a log file, and we want to archive the log files every day. The easiest way to rotate these logs is to create a batch file that copies the log file to a filename that includes the date of the file as the file name. Now, we can’t really […]

We recently had to monitor a farm of Windows servers with Performance Monitor. True, we could add one counter at a time from the various servers… point, click, wait, pulldown, click, ok, click…. aaarghhh. Burning hot pokers in the brain working on these boxes. Now, it turns out that you can edit the log settings […]

One problem with monitoring servers over a WAN is that the WAN is often down during the night. Now, if the WAN is down hard, that is a separate issue. But, just because a host does not respond to a ping does not mean the WAN is really down, or that the server is down. […]

We introduced a ping monitoring program in this article. In this article, we will start documenting our script by going over the main routine: use Time::Local; use Mail::Sendmail; use Net::Ping::External qw(ping); $pmwrap=0; while (6 ne 9){ # Loop forever… I don’t mind. system(“cp new.dnsf dnsfc”); # Each pass through the servers, copy dnsf again to […]

In this article we introduced a ping monitoring perl script. We talked about the main routine in this article. Now, let’s go over the printtime() and ckserv() functions. The printtime function simply writes a timestamp to mon.txt: sub printtime{ open (PM,”>> mon.txt”); ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(time); $mon++; $year=$year+1900; print PM “\n”.$mon.”/”.$mday.”/”.$year.”-“.$hour.”:”.$min.”\n”; close PM; } The >> in the […]

A couple of modules that we use in our ping monitoring script are Mail::Sendmail and Net::Ping::External. To install these, use the CPAN shell to search for the available Sendmail mods: root@srv-1 root # perl -MCPAN -e shell Warning [/etc/inputrc line 28]: Re-binding char #27 from [F_ViEndInsert] to meta for [91 49 126] => BeginningOfLine. cpan […]

Pf and rf are the two final subroutines we need to discuss for our Ping Monitoring Over a WAN perl script. Both modules use the Net::Ping::External module, which we chose because it works on Windows and GNU/Linux (and because of this, probably works on most every platform that perl runs on). Here is the pf […]

One of our networks has just a few production Windows servers on it, and a whole bunch of Linux boxes. Being a Unix sysadmin by trade and inclination, this situation is mostly dreamy except for one thing: auditing the event logs on the Windows servers. We can’t just put our head in the sand and […]

Ps-watcher can run ps periodically and match patterns based on the output of ps. You can check for memory usage, number of processes, etc. Let’s grab the program and try to compile: [root@test psw]# ls ps-watcher-1.0.tar.gz [root@test psw]# tar -xzf *.gz [root@test psw]# cd ps* [root@test ps-watcher-1.0]# ls aclocal.m4 configure install-sh mkinstalldirs README touch.pl AUTHORS […]

One extremely annoying thing to get alerted about in the Windows application logs are the Perflib errors: The Open Procedure for service “pcAnywhere” in DLL “C:\Program Files\ Symantec\pcAnywhere\PcaPerfCtrs.dll” failed. Performance data for this service will not be available. Status code returned is data DWORD 0. or: The Open Procedure for service “ISAPISearch” in DLL “QPerf.dll” […]

I wondered how to monitor load on my GNU/Linux boxen. Sure, there are a lot of canned apps out there. But what if I wanted to use Perl? (IUD SIS, you must use Perl, cuz Perl’s the best… Readin’ from my Camel book like you wanted me… script the pain away…) Anyhoo… I wanna use […]

There is a service we wrote available at AreWeDown.com that will measure the network health of TCP connections. It does this by issuing two insert commands via a MySQL ODBC connection from a system service at 30 second intervals. The idea is that this can be loaded on XP workstations at client sites on the […]