Monitoring Archives - Igor Oseledko

Converting Geofency Data to Google Maps

Igor — Sat, 07 Feb 2026 17:25:10 +0000

Originally published February 8, 2023 @ 8:57 amGeofency is a time and location tracking app for iOS. I’ve been using it for many years to keep track of my whereabouts. At times, this information can come in quite handy. The app does not track your movements continuously. Instead, it uses Geofencing and iBeacon technology, which […]

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Analyzing atop Logs with atopsar

Igor — Fri, 21 Nov 2025 01:48:02 +0000

Originally published November 22, 2019 @ 5:38 pmI have discussed atop previously but concentrated primarily on how to run it and how to collect data. Now I’d like to spend some time talking about ways to analyze the data collected with atop. Included with the atop package is atopsar – a utility design to extract […]

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Verifying SNMP Connectivity on Multiple Hosts

Igor — Sun, 05 Oct 2025 22:50:36 +0000

Originally published October 7, 2019 @ 2:42 pmI needed to check if SNMP was accessible on whatever live servers that existed in a particular subnet. Here’s a quick script to do this. You will need to specify subnet information and the SNMP community string. The script will use nmap to find live hosts and will […]

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Selecting Time Ranges from Logs, Part 2

Igor — Fri, 03 Oct 2025 01:54:56 +0000

Originally published October 4, 2019 @ 3:14 pmA couple of years ago I wrote an article about selecting specific time ranges from log files. I proposed two options: either convert all timestamps to epoch format (a CPU-intensive process) or rely on regex (limited to specific date/time periods). Here’s a followup with a couple more methods. […]

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Server and Application Resiliency Testing

Igor — Mon, 08 Sep 2025 22:01:08 +0000

Originally published September 9, 2022 @ 1:15 pmYou are deploying a new application cluster and wonder how it will perform under less-than-ideal conditions: heavy system load, slow storage, network performance degradation. Application resiliency testing is integral to any application architecture but is often passed over because the process is considered overly complex and time-consuming. Here […]

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Analyzing Network Performance

Igor — Sun, 17 Aug 2025 01:46:05 +0000

Originally published August 18, 2019 @ 7:09 pmMuch of network performance analysis will be comparative in nature. Thus, seeing the output of multiple commands side by side can be quite useful. Bash has a useful little utility called pr and we’ll make use of it. Side-by-side traceroutes Step 1: create hostlist.txt and populate it with […]

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Raising Dead Services

Igor — Fri, 08 Aug 2025 03:23:11 +0000

Originally published August 8, 2019 @ 2:22 pmI suppose you may say all of this can be just as easily be done via systemd service config files. Well, yes and no. Yes, it can be done. And, no, not as easily. Not even close. Because systemd sucks by design. But this is a subject for […]

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Working with ffmpeg on Multi-Core Systems

Igor — Fri, 01 Aug 2025 02:33:39 +0000

Originally published August 1, 2019 @ 9:25 pmWhile ffmpeg has multithreading capability, getting the best performance on multi-core systems calls for something more than just playing with the -threads option. I’ve seen suggestions to set the -threads option to 1.5 the number of cores, which doesn’t make any sense. The most common choice for this […]

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Late Night Rant: College Admissions Scandal

Igor — Tue, 08 Apr 2025 17:55:19 +0000

Originally published April 9, 2019 @ 9:43 pmThis is America: you’re either a duper or a dupee. I’m a duper. You guys are the dupees. — Frank Reynolds (Danny DeVito), It’s Always Sunny in Philadelphia How will the 2019 college admissions scandal work out? Likely to the best interest of most everyone directly involved. Individuals […]

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Measure DNS Server Performance

Igor — Thu, 09 Jan 2025 15:57:51 +0000

Originally published January 10, 2019 @ 6:35 pmThis is not an entirely proper way to benchmark a DNS server, but, in a pinch, it should give you some idea of its responsiveness and stability. The commands below require dig (provided by the bind-utils package), and shuf (provided by the coreutils package). Pretty standard stuff you […]

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