Elon Musk jet tracker banned from Twitter

Hypocrite Elon Musk has finally banned all Jet tracker accounts on Twitter, despite claiming that he supports freedom of expressions. Of course, the hypocrite only supports expression about things he agree with.

In any case, Jet tracker has moved to Maston. Here https://mastodon.social/@elonjet

Original article here: https://techcrunch.com/2022/12/14/elon-jet-the-twitter-account-tracking-elon-musks-flights-was-permanently-suspended/


Supply chain attacks on open source

Watch out if you are using libraries and code from public repositories. Supply chain attacks are (have been) on the rise.

The latest one is on Rust.



How To set limit on systemd services

This is a cookbook style on how to set a limit (ulimit style) on your custom services that is managed by systemd.


Why would you want to do something like this?

You might be running on a small server (or instance if you are using cloud services) and want to prevent your application from affecting other services sharing that server (think of noisy neighbor problem).

Generally, Linux kernel scheduler does a good job of fairly sharing system resources, but that is assuming you have a well behaved application.

Sometime you want to pack applications tightly and don’t mind less performant applications.

In summary, there are lots of reasons why you might want to tune the resources allocated to your applications.

Luckily, if you are using systemd as the controller, you can take advantage of its capabilities.


There are some caveats. You need to be using a fairly recent kernel and Linux distrob, either Ubuntu/Debian or recent CentOS/RedHat/Fedora.


I am going to show you how to get cloudquery run under systemd on an Ubuntu 20.04 LTS. The reason that I want to do this is because cloudquery will use as much memory as it can and trigger Linux OOM killer.


There are 3 files needed:

  • /etc/default/cloudquery
    • This file contains definition for CQ_SERVICE_ACCOUNT_KEY_JSON, the value of which is the json content of your service account key file.
    • Example:
      • CQ_SERVICE_ACCOUNT_KEY_JSON='{ “type”: “service_account”, “project_id”: “foobar”, “private_key_id”: “1a23b456cd134”, “private_key”: “—–BEGIN PRIVATE KEY—–\n…..vA8r\n—–END PRIVATE KEY—–\n”, “client_email”: “[email protected]”, “client_id”: “1234567890”, “auth_uri”: “https://accounts.google.com/o/oauth2/auth”, “token_uri”: “https://oauth2.googleapis.com/token”, “auth_provider_x509_cert_url”: “https://www.googleapis.com/oauth2/v1/certs”, “client_x509_cert_url”: “https://www.googleapis.com/robot/v1/metadata/x509/foobar-sa%40foobar.iam.gserviceaccount.com” }’

  • /lib/systemd/system/cloudquery_limit.slice
    • [Unit]
      Description=Slice that limits memory for all my services

      # MemoryHigh works only in “unified” cgroups mode, NOT in “hybrid” mode
      # Must add ‘systemd.unified_cgroup_hierarchy=1’ to GRUB_CMDLINE_LINUX_DEFAULT
      # in /etc/default/grub
      # MemoryMax works in “hybrid” cgroups mode, too

  • /etc/systemd/system/cloudquery.service
    • [Unit]
      Description=Cloud Query

      ExecStart=/usr/local/bin/cloudquery –config /data/cq/config.hcl fetch
      ExecReload=/bin/kill -HUP $MAINPID


Once you have all 3 files in place and edited the values to match your particular system, you need to tell systemd to check its directory for the new service, by running

systemctl daemon-reload

Once you have done that, you can check to see if systemd see your new service, by running

systemctl list-unit-files|grep query

Smoke Test

Test to see if everything works by starting your service.

systemctl start cloudquery

Check (and debug) the status of your new service via

systemctl status cloudquery

and journalctl -xe

Thanks to the posts from https://unix.stackexchange.com/questions/436791/limit-total-memory-usage-for-multiple-instances-of-systemd-service for pointing me in the right direction.

Meetup – Introduction to Quantum Computing

Sillicon Valley – Santa Clara, CA Meetup


This is a simple first event in public interest to attract talents in Silicon Valley and globally to understand what is in store for with Quantum Computing as it evolves over next few years to become the next technology to change Computing , Communications & Sensing that start trickling onto main stream Digital, Operations and Knowledge transformation.

As a humble beginning like to introduce Quantum Logic and compare with Digital Logic to garner to see how one can leverage the cloud hosted free offerings from IBM, Google, Amazon and others to get informal education and see how this pans out as open technology for startups and hobbyist to innovate and use DIY way to build their skills for future opportunities.

This will be a 18 week effort every Monday evening 6.30PM PDT / 9.30 PM EST / 7.00 AM IST for 1:30 hrs:mts. Ist and last week ie. 1st & 18th Monday will be Opening and closing events. So don’t miss the actions to become qualified to handle Quantum Technology.

The easiest way to do will be have Subject introduction and follow up with interactions to set goals for one quarter and see how it shapes up. Doing this weekly for few weeks should help us consolidate and plan the course of actions.