Is It a Recommended/Best Practice to Use Email as a Component in Two Factor Authentication?

Problem scenario
You want to implement a secure protocol for authentication. You want there to be a password and a second factor of authentication. Can an email (being in possession of an inbox) be a factor in MFA?

Answer
Maybe.

No, according to NIST:
https://pages.nist.gov/800-63-FAQ/

But many companies do use email as a factor in multi-factor authentication.

(This is about setting up email in general. It does not pertain to a specific vendor's implementation of email.)

How Do You Get Hotel Refrigerators to Not Freeze Your Food?

Problem scenario
You go to hotels with mini-refrigerators. What appears to be a small fridge is actually a freezer from a pragmatic perspective. Your food (e.g., apples or fruit) get destroyed when they are frozen. You want a fridge, but everything seems to freeze your food. What should you do?

Solution
Turn the temperature down. If you open the fridge and do not see a thermostat, temperature gauge changing device, close the fridge. Look on top of the fridge on its exterior near the back of the fridge. If the fridge is recessed inside a cabinet, you may need to pull the fridge out. On Tatung fridges (e.g., TR-4RD), the temperature setting device is on the top in the very back of the fridge. Here is an example:

The arrow should point to 1.8 to possibly 3. Any lower than 1.8 may not be cold enough. Any colder than 3 may be too cold for "most" people (for the most Tatung minifridges). A setting of 6 or 7 can freeze your food.

How Do You Troubleshoot OOM Errors with Restarting Pods in Kubernetes?

Problem scenario
You find out-of-memory (aka OOM) errors in Kubernetes. The node seems healthy. The pods keep restarting. What should you do?

Possible Solution #1
Are you using a burstable quality of service (aka QoS) with the pods? There may be a non-pod-specific reason and the burstable Pods are being starved of resources. The node may be getting requests for other pods with a superior quality of service. If you change the other Pods' QoS or the QoS for the Pods being restarted, that may help.

Possible Solution #2
Is the node actually not healthy? If the memory is having a hardware problem, you may think the node is fine, but there is a small chance that the node is in fact not healthy.

Possible Solution #3
Can the restart rate of the pod be changed? It may be set to a high frequency. This could be a contributing factor to the restarts themselves.

How Do You Troubleshoot “ERROR: Hadoop common not found” when Running Hadoop?

Problem Scenario
You run an HDFS command, but you get this message: "ERROR: Hadoop common not found"

What should you do?

Solution
As the hduser or user that runs hdfs, log in. Run "echo $HADOOP_HOME"

That directory should have a libexec directory with a file called hadoop-config.sh.

Run this: ls -lh $HADOOP_HOME/libexec

One way to create it is this: 1) find a hadoop-config.sh file (e.g., with a "sudo find / -name hdfs-config.sh" command). 2) run this command sudo ln -s /path/to/hdfs-config.sh $HADOOP_HOME/libexec/hadoop-config.sh

Be mindful of the "hadoop-config.sh" and "hdfs-config.sh" difference; it is subtle.

(This is the for open source version and not a specific vendor's implementation of Hadoop.)

In I.T., what is a Schema?

Question
In computing, what is the definition of a schema?

Answer / schema disambiguation
Outside of the I.T. realm, Merriam-Webster's Dictionary (11th Edition, on page 1110) defines schema as "a diagrammatic presentation; broadly: a structured framework or plan: outline." This definition must have influenced the appropriation of the word to refer to concepts in I.T..

For Kubernetes
"Schemas are the set of JSON files for various Kubernetes versions, extracted from the OpenAPI definitions." (Taken from https://medium.com/trendyol-tech/how-can-we-accomplish-our-kubernetes-schemas-validation-against-our-clusters-e521af390322 .) Schemas can be downloaded from GitHub (e.g., in the form of a .tar.gz file) and uncompressed on to a server or pod.

For relational databases
In relational databases a schema defines relationships and the inner configurations of the database such as foreign key constraints between tables (per this posting https://stackoverflow.com/questions/29155012/referencing-the-foreign-key-of-another-schema).

A schema can be thought of a blueprint inside the database (per
https://techmonitor.ai/what-is/what-is-schema-4944519).

As there are many different types of relational databases, each one tends to have a different type of schema. For example, there are details about Oracle, PostgreSQL and SQL Server schemas that vary from product to product. Schemas can be specific to users, tables or other objects.

In some contexts, different types of schemas become important such as logical or physical schemas; to read about the differences of these types of schemas, see this https://stackoverflow.com/questions/22067378/what-is-the-difference-between-logical-schema-and-physical-schema/22069941#22069941

To learn about a user's schema in Oracle, see this: https://docs.oracle.com/cd/B19306_01/server.102/b14220/schema.htm

In SQL databases the DROP SCHEMA command (note that "DROP" is a DDL, not a DML, command) will remove the schema and the objects related to that schema.

To view the schema that governs a table in MySQL, use the "DESCRIBE" command like this (but replace "foo" with the database name and "bar" with the table name):

DESCRIBE foo.bar

(This was adapted from https://www.tutorialspoint.com/how-do-i-show-the-schema-of-a-table-in-a-mysql-database .)

For XML

An XML schema will define the elements of one or more XML files. Here is an example:


 <?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="note">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="to" type="xs:string"/>
      <xs:element name="from" type="xs:string"/>
      <xs:element name="heading" type="xs:string"/>
      <xs:element name="body" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

</xs:schema>

It was taken from https://www.w3schools.com/xml/schema_intro.asp

Another definition (with a very similar example) can be found here: https://techterms.com/definition/schema

XSD stands for XML Schema Definition. A pom.xml file for Maven may refer to an .xsd file. To see an XML, click here.

For Terraform
See this internal posting.

For Pulumi
See this internal posting.

What Musical Instruments Did the Signers of the Declaration of Independence Create?

Question
Some of the signers of the Declaration of Independence invented new musical instruments. Who were they and what did they invent?

Answer
Francis Hopkinson invented the Bellarmonic that involved steel bells (https://loc.gov/item/ihas.200035713). Ben Franklin invented the armonica (https://pubmed.ncbi.nlm.nih.gov/11855437/). To listen, click on this: https://www.youtube.com/watch?v=eEKlRUvk9zc

Digital Upgrades to Keep Your Business from Falling behind

Digital Upgrades to Keep Your Business From Falling Behind

Businesspop.net shares a post today intent on helping small businesses get ahead in the digital age.

As a small business owner, you have a lot on your plate. You have to keep your profits in the black, make sure that your customers are happy, and ensure your employees have the tools they need to be effective. Fortunately, these things are made easier through digital innovation. Here are a few bits of technology that are easy to integrate.

Business Process Management

We’ll get the most confusing out of the way first: business process management (BPM). Business process management is simply the act of installing software and improving your business operations by streamlining. This way, you reduce time by automating aspects of certain tasks. Business process management can be thought of as a framework instead of a specific program, and, no matter what you choose, you’ll want to keep an eye on its effectiveness and make tweaks to improve efficiency and performance. A quick note here is to make sure that any technology you add to your business will be fully supported. You can do this by calling tech support to see if you get a live human or the digital runaround.

SMS Communications

Text messaging is one of the best ways to reach your customers and, in fact, customers tend to prefer text and email over any other type of communication. This doesn’t mean you have to text your customers individually, and there are many apps and programs you can use to send monthly marketing communications and even personalize promotions. A few of these include Twilio and Mobile Text Alerts. Wholesale SMS marketing company HORISEN explains that there are many benefits of switching to an SMS platform, including low-cost, global reach, and having a direct link to your customers.

Digital Marketing

In addition to SMS, there are many other digital marketing platforms that can help you improve your operations. This includes things like social media, influencer, video, and display marketing and advertising. 99 Designs offers more information on these and six other important digital marketing avenues that all small businesses should consider.

Data Visualization

Data visualization is taking complex information and squishing it down into an easy-to-read format. Charts, graphs, and infographics are great examples of visualized data. You can use this in your small business to easily relay information and insight to your customers, employees, and even shareholders. These snapshots help your audience to determine which data is worth diving deeper into and which they’d rather leave at face value. This can save time and money and help everyone make better decisions.

In our digitally-advanced world, technological tools are available for businesses of all sizes. Don’t let the competition speed ahead of you on the information superhighway. Spend the time now implementing even simple upgrades, and you may very quickly see a return on your investment in time, efficiency, and profitability.

Visit the Continual Integration blog often for more tech topics.

Image via Pexels

Disclosure

This article was brought to you by Businesspop.net.

How Do You Troubleshoot the Error Message “usermod: group ‘wheel’ does not exist”

Problem scenario
You run "sudo usermod -aG wheel jdoe" but you get "usermod: group 'wheel' does not exist." What should you do?

Possible solution #1
Run this:

sudo usermod -aG admin jdoe

Some Linux distributions such as Ubuntu* use "admin" instead of "wheel"

You may want to read this for further information.

How Do You Troubleshoot /etc/sudoers Changes Not Working?

Problem scenario
You modified the /etc/sudoers file. The changes do not seem to have taken effect. What should you do?

Solution
99% of the time you do not need to log out or log back in. You should not need to open another terminal. For the stanza that you added, did you append it to the bottom? The problem may be that the stanza you added was in the middle of the file. If you are new to editing the /etc/sudoers file, try putting the stanza at the bottom. The changes should take effect instantaneously.