Problems starting Eclipse after updating JDK on OSX

I came across this problem when updating jdk via brew. Somehow brew removed openjdk-12 and replaced it with 14. Pesky.

After some checks, I figured the Eclipse 2020-06 executable was relying on a hardcoded openjdk path.

To rectify this, I’ve done the following:

  1. Determine the jvm available on osx by dropping to command line and running ‘/usr/libexec/jvm_home -V’

Below is a screen capture of the available openjdks on my OSX. (openjdk-12 was removed somehow). Remember the location of the openjdk directory you wish to use.

2. Edit the openjdk path in eclipse.ini. The path to eclipse.ini is as follows:

Note: I have mine in $HOME/eclipse/java-2020-06. Yours could be in the Applications directory (ie /Applications/Eclipse)

Run ‘nano eclipse’

3. To get this:

eclipse.ini pointing to missing openjdk-12 folder

4. Amend the folder name to the openjdk directory that you’ve determined in Step 1.

I’ve selected openjdk-14.0.2.jdk

5. Ready to start Eclipse by running the eclipse executable.

Adjust Time Machine backup frequency

I managed to get a oldish 3Tb Time Capsule off Carousell for experimenting. It was pretty alright for the first day until I got tired of the hourly loudish HDD spin up.

There must be a way to adjust the hourly backup frequency to every 6 hours. Given this is a oldish EOLed device, I also want to preserve its longevity – as much as i can.

To do so, determine the new backup frequency you want it to be, knowing the backup daemon reads in the backup frequency in seconds.

If you want to adjust to a 12 hour backup, the new number would be 60 seconds * 60 minutes * 12 hours = 43,200

For a 6 hour backup frequency, the new number would be 60 seconds * 60 minutes * 6 hours = 21,600

Next,

  1. Go to the macOS terminal app and do the following:
  2. Unload the backup daemon using “sudo launchctl unload /System/Library/LaunchDaemons/com.apple.backupd-help.plist
  3. Change frequency on the the following file /System/Library/LaunchDaemons/com.apple.backupd-helper.plist using “sudo nano /System/Library/LaunchDaemons/com.apple.backupd-helper.plist
  4. Look for the line that says “<key>Interval</key><integer>3600</integer>“, change the integer value to the newly calculated value above without the comma.
  5. It should read the following with a 12 hour backup frequency “<key>Interval</key><integer>43200</integer>
  6. Save the file with Ctrl-X.
  7. Then reload the plist using “sudo launchctl load /System/Library/LaunchDaemons/com.apple.backupd-help.plist

You will only hear the HDD storage startup only twice a day, and extend the HDD’s life!

PS – The above was verified to work on Mojave.

PPS – You will need to do this for every macOS device.

Another good reason for using macOS (Resetting router password)

I got stuck resetting a router’s administrative password. While I had the required Cisco cable (console to serial) and a Usb to Serial adapter, Windows 10 wasn’t too happy with the Usb to Serial adapter I had.

Windows 10 said the Usb to Serial adapter was too old and wanted me to “CONTACT THE DEVELOPER”. No kidding, that’s what was written on the Devices page.

Switching to the MBP, I connected the Usb end of the Usb – Serial cable and did a

screen /dev/tty.usbserial

And I got a response from the router immediately.

Local firewall for Windows and MacOS

I’ve been on the MacOS platform for over 8 years now and am quite pleased with Little Snitch. I’ve got to look for another one which works with Windows, now that I’m switching over to Windows 10 for work. These are some which I have found.

From what I’ve read, it appears NetLimiter 4 is the only one that allows you to allow/deny individual connection, like Little Snitch. I’ll be installing it to test out. The screenshots on the Netlimiter page makes me just want to head back to MacOS. 🙁

“The Blockchain hype has slowed : where has it gone and why?” – e27.co

https://e27.co/the-blockchain-hype-has-slowed-where-has-it-gone-and-why-20190906/

Hath the blockchain euphoria finally died a quiet death?

I’ve been saying this to 1. customers, 2. tech friends, 3. lesser tech friends, 4. non-tech friends. Not one believed me apart from the Vandy tech gang (where the real tech people are).

Hope the SG govt didn’t throw in good tax payers $ into this slow database.