proflehman.com live at AWS

The proflehman.com website is officially migrated to AWS!

All data files, about 9 GB, were backed up from IONIS via FTP. Most of that space came from archived family reunion photos (2012, 2014, and 2016) I’d been hosting on the site.

After confirming that both proflehman.com and basingerlehman.com were transferred to AWS, I submitted the online request to cancel my IONIS contract (required a quick phone call for verification). I had been a customer since 2007 and had no issues with IONIS (formerly 1and1.com), but I wasn’t using their resources and wanted to gain experience with AWS.

In AWS Route 53, I created a hosted zone for proflehman.com and updated the name servers. I also added an entry for www.proflehman.com. Using DNS Checker , I could see propagation begin within 5–10 minutes.

I used ChatGPT to guide me through the migration steps, which was very helpful for understanding the process. I also used the bncert-tool to quickly request and install a free Let’s Encrypt SSL certificate for my WordPress site (It’s running on a Bitnami pre-configured WordPress stack in AWS Lightsail.).

While I’m using Route 53 for DNS, AWS Lightsail appears to offer free DNS for associated domains, unlike Route 53’s $0.50/month hosted zone fee. I haven’t set up DNS for basingerlehman.com yet and am still deciding how to handle it.

Now time to update the WordPress design and maybe start posting more often.

DNS propagation map

Finally … shutting down 1and1.com account

Well, in an effort to “declutter”, I am finally getting around to shutting down the IONIS (formerly 1and1.com account).

  1. It looks like I fixed the image issue by downloading the images and adding them to the media library.
  2. I backed up all files stored at IONIS via FTP. I had images and some conference documents stored.
  3. I saved another copy of my old WordPress site using HTTrack website copier. Note: had to specify that images should be saved, set the minimum link level to check, and turn off the check robo .txt file (whatever that is).
  4. I had to get access to WordPress on AWS again by updating the admin password in the database.
  5. I first transferred basingerlehman.com to AWS Route 53. I had to open the domain at IONIS and get an authorization code. Process took about five days (lost track). Had to validate my email address with ICANN.
  6. So, today I just started the transfer of proflehman.com to AWS Route 53. Will need to fix DNS and need to look at DNS options. AWS Route 53 charges for DNS, not sure it is worth the extra cost.

Stay tuned …

Migrating to AWS …

light sail logo

Finally working on migrating my ProfLehman.com blog to a different server. This post is on the new site hosted at AWS using their Lightsail server. I used the smallest micro server instance with 512 MB of memory and 20 GB of storage which is $3.50 per month (2022). I used the pre-built WordPress image which meant the server was running in a just a few minutes.

Steps …

  • Created the Lightsail server instance
  • Backed-up and downloaded old site using UpdraftPlus WordPress plugin. I used the free version.
  • Uploaded back-up files and restored on new site
  • Logged into mysql to fix WordPress user password that was lost as my original user account was lost in the transfer 🙂
  • Changed the server instance to use a static IP address

So … remaining issues … my images still have a reference back to the old web host. I think this can be changed either by editing the post in WordPress or by going into the database.

My next step is to transfer and link my ProfLehman.com domain name.

Is there anybody out there? … moving the blog.

Is there anybody out there still reading this blog? I doubt it, but that is OK. A new post every two years does not attract a following.

A lot has happened since I started this blog back in August of 2007 including the widespread availability of cloud-based servers.

I have been running a test server on Amazon web serves since May 2019 to see what the cost would be. $9.47 a month or $113.64 a year. Amazon certainly has one of the widest sets of cloud computing services, but seems to be overkill for my personal web site.

It currently costs $131.88 to host this site with IONIS (formerly 1and1.com) which includes two domain registrations for proflehman.com and www.basingerlehman.com.

I am going to try to move this blog to Digital Ocean using their smallest droplet server which is currently $5.00 per month. Digital Ocean does not offer domain name registration, so will need to sort out how to register my domain names. For $60 a year plus the cost of registering my domains I should be able to host my web site on Digital Ocean.

Of course this will require me to install and management my own server, but should provide more flexibility and should learn much along the way. I plan to update this blog throughout the process.

Drop me a line in the comments section if you are still reading this blog or have used a cloud server to host your own website/blog.

-Prof. Lehman

Advent of Code Update 2017

The Advent of Code has continued for 2016, and 2017.  I worked through the 2017 problems and was able to complete most problems on the day they were released.  My schedule was a bit busy Christmas Eve, so complete both December 24 and 25th problems on Christmas day (fun!).  I also went back and completed all of the problems from 2015 and 2016.  I have been using Java for most of the problems.  The completed tree for 2015 is shown.  You can still complete any of the problems from previous years.

Advent of Code 2015

Microsoft Excel 2013 maximum number of rows and columns

In Microsoft Excel 2013 the maximum number of rows is 1,048, 576 and the number of columns is 16,384.  These may seem like strange numbers.  Why not 1,000,000 rows? and 10,000 columns? The answer lies in how computers store numbers using binary (or base 2) which only uses the symbols 1 and 0.

The number of 1’s and 0’s (known as bits) that are allocated for storage limit the range of values.  The number of values that can be represented is equal to 2^(number of bits).  In Excel 2013, 20 bits are used for the number of rows, thus there are 2^20 or 1,048, 576 rows.  For the number of columns, 14 bits are used, thus there are 2^14 or 16,384 columns.  Columns are labeled using letters.  This is essentially a base 26 scheme where A = 1 and Z = 26.  The last column is XFD (ie. 16,384).

The last cell in Excel 2013 is XFD1048576.

Excel Limits Showing Max row and column