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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Monitoring’ Category

Some uptime monitoring tools that are still free and understand more than http/https

Posted by jpluimers on 2022/01/19

Since uptimerobot has slowly moving free features, part of my family uses it to monitor uptime of their personal stuff, and I don’t want to pay for the free monitoring I do on Embarcadero infrastructure (I know that they have been phasing out older useful sites for ages, but even their main sites were down for 2 days about a year ago).

Yes, I know the competitiveness of [Wayback] Website monitoring – Wikipedia, and I’m glad Uptimerobot has been there for a relatively long time, but alas: for personal use…

The list of of the pricing pages of each site, containing a one line summary blurb if it was available:

Via [Wayback] 16 Best Online Services to Monitor Sites Uptime

Related: [Wayback] EmbarcaderoMonitoring: www http


Posted in *nix, Delphi, Development, Monitoring, Power User, Software Development | Leave a Comment »

Binding #Uptimerobot monitoring to your own subdomain:

Posted by jpluimers on 2021/01/01

Below a few screenshots on how to bind your own subdomain to a set of uptimerobot monitors.

This case is about [, which I setup because of the not so well way that Embarcadero maintained their web facing infrastructure in the past.

The steps for that are really simple, assuming you already have an uptimerobot account and some monitor set-up. If you don’t: check out the first video (thanks onewebstreet!) linked below the fold, as it is a step-by-step introduction.

Steps for your own subdomain

If you like video more than a list of steps, check out the second video (thanks Kyle!) below the fold.

  1. Ensure you have a DNS CNAME record that points your subdomain (in my case to

    Note that [] by itself will not display any dashboard, as it requires a CNAME to be involved that is registered in the Uptime robot Custom Domain list.

  2. Login to Uptime robot, which brings you to
  3. Click on settings, which brings you to
  4. Observe the “Disable RSS” (or “Enable RSS” if you have not yet enabled it) and the “this link” (which in my case points to this RSS feed [WayBack])
  5. Clicking on “show them” will get you something like this:
  6. Clicking on the pencil icon then will get you where you can set the “Custom Domain”, which notes

    Custom Domain

    (make sure you create a CNAME DNS record for your domain to And, it can take up to 30 mins for the custom domain to be activated.)

  7. Wait a while and check your CNAME for a valid Uptime robot status dashboard.


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Posted in *nix, LifeHacker, Monitoring, Power User, Uptimerobot | Leave a Comment »

Uptimerobot: TCP uptime only verifies the three-way TCP handshake

Posted by jpluimers on 2020/12/28

I like uptimerobot a lot (wrote about it earlier, and will write about it soon again), but there are two important things to keep in mind on how it does connection uptime verification:

  1. HTTP checks: [WayBack] Introducing “HTTP Method Selection” (HEAD/GET/POST/PUT/PATCH/DELETE) | Uptime Robot – Blog
    • HTTP requests by default are HEAD for plain HTTP monitors or GET for HTTP keyword monitors, but in the advanced settings, you have options to choose other methods as well: HEAD/GET/POST/PUT/PATCH/DELETE are supported, which means the only unsupported methods (see Hypertext Transfer Protocol: Request Methods – Wikipedia) are TRACE/OPTIONS/CONNECT.
  2. TCP checks: [WayBack] New Feature – Monitoring Ports | Uptime Robot – Blog

If you want to see a few specific TCP protocol tests in action, then check these:

I did not find a good site to test IMAP servers in a simple way like the above sites. If anyone has one: please share it in a comment below.

I did find a post with public FTP servers (they are becoming rare): [WayBack] Is there a Public FTP server to test upload and download? – Stack Overflow


Posted in *nix, Monitoring, Power User, Uptimerobot | Leave a Comment »

Great tool: the Toptal Colorblind Web Page Filter

Posted by jpluimers on 2020/08/06

Colorblind Web Page Filter

Colorblind Web Page Filter

A great tool I found out about a while ago [] Toptal Color Blind Filter.

It shows the original web page and the rendering for various types of color blindness:

  • protan -> Protanopia: red/green color blindness; anomalous red cones
  • deutan -> Deutanopia: red/green color blindness; anomalous green cones
  • tritan -> Tritanopia: blue/yellow color blindness; anomalous blue cones
  • grey -> Greyscale/achromatopsia: quick check for all forms of colorblindness

Because of a comment at [WayBack] Forums… – JWP – Google+, I used Toptal to notify Uptime robot that their status pages are hard for color blind people: [WayBackJeroen Pluimers on Twitter: “Some color blind people indicated to me that @uptimerobot status pages are hard for them to read. Examples are for @EmbarcaderoTech as they have subdomains being offline often: …”, so lets look at how people with various types of color blindness see :

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Posted in *nix, Color (science), Color (software development), Development, Monitoring, Power User, science, Software Development, Uptimerobot, Usability, User Experience (ux), Web Development | Leave a Comment »

Duh moment: when is querying your DNS infrastructure and it appears to be uptimerobot

Posted by jpluimers on 2020/07/28

From the hindsight department [WayBack] Nice when someone in Dallas using is querying your DNS infrastructure for many permutations of domains…… – Jeroen Wiert Pluimers – Google+.

Wolfgang Rupprecht gave me some hints on the cause, as the IP address Google Search used to be of a gaming server: [WayBack] TwotailsTikat’s Profile – Member List – Minecraft Forum

After a good night sleep,

# nslookup name =

In retrospect: perfectly normal behaviour for monitoring machine “snip”.

Log by


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Posted in *nix, DNS, Internet, Monitoring, Power User, Uptimerobot | Leave a Comment »

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