Sohan's Blog

Things I'm Learning

All Talk No Show: Software Architecture

We have a problem with software architecture. Let’s face it. Find the architecture diagrams of the products you’re working on and answer these questions:

  1. Did you find it?
  2. Does everyone in your team know where to find it?
  3. Is it up-to-date?
  4. Can you see how this system scales, handles failover, monitors performance, or how it’s secured?
  5. Can you see how it evolved over time?
  6. Can you train a new team-member using this diagram?

This is the first micro-post of a series of such as I aim to build a compelling case for fundamentally changing software architecture diagrams.

Play at Work

paper plane

Image source: Kalvis

“I am a mango”.

First, mangoes are in-season, and I still remember the juicy sweetness of the mango I had just the night before. So, when the coach asked each of us to be a fruit, I didn’t think twice. One of my coworkers was a kiwi, another one apple, and so on. The idea was to group us by color, then by size. This got us, twenty people in the class, moving and engaged. It was part of a two-day design thinking course. The coaches used the fruit game to bring some energy into the room as well as to pave the way for the next exercise - grouping a bunch of ideas by cost and the level of innovation.

I find that professional trainers bring play at work, especially for sessions that span hours or days. However, on a typical day to day business, I don’t see much play activity at work. Hoping to bring in some play activities to my work going forward. Here are some ideas for play activities based on what I saw so far:

Paper planes: Having small groups build paper planes and the winner has the most number of planes crossing a line.

Catch and throw: A ball or a ball-like object changing hands and the person catching must find someone that didn’t catch it already.

Portrait: Everyone draws a portrait of another person looking at their face without looking at the paper.

Quiz: An online quiz that maintains a leaderboard throughout a session.

Exercise: Getting everyone out of their seats to do a quick one-minute exercise.

Internal Trainings

design_thinking

Design Thinking course, Cisco Calgary Office, AB, 2019

One benefit of working at Cisco is access to the many learning and development resources. Our learning and development org arranges hundreds of courses throughout the year. Moreover, we have a reimbursement program for external courses, conferences, books, and subscriptions to online learning programs and publications.

In the past 6 years, I have immensely benefitted from these resources. Here’s a list of the learning resources I’ve used.

  1. Safari books online, aka O’Reilly learning: In the past 3 years, have taken 3 online trainings and 7 books on this platform so far.
  2. Design thinking, 2019: A two-day course taught by consultants about how to apply the principles of design thinking to communicate and derive solutions to complex problems.
  3. Mindfulness, 2019: A 5-week program taught by consultants, with one hour per week, where I learned about staying mindful and effective at work amid all the chaos that surrounds it.
  4. Tufte one-day course, 2019: Attended a course taught by Edward Tufte on data visualization and learned about the principles that make compelling data visualization.
  5. SANS incident response, 2018: A packed week-long program where I learned to think like a hacker by learning about and then hacking some interesting vulnerabilities in systems.
  6. Cisco R00tcamp, 2017: A packed week-long program where I learned hands-on pen-testing techniques to build more secure software.
  7. Cisco threat-hunting, 2017: A daylong course to find root case that triggered a security threat using integrated Cisco tools, including the product I build with our team.
  8. RailsConf, 2015: It was a big opportunity to meet the community and bring some of their practices in-house. For example, we started using BugSnag after learning about it in the conference.

Polyglot YYC 2019: My First Unconference

polyglot_yyc Source: Polyglot YYC

This weekend I went to Polyglot YYC 2019. It’s a gathering of tech people from around Calgary. The event was open to all possible topics, hence the name Polyglot. It was the first unconference style meetup I went to and this post is a summary of my day.

About the attendees, I don’t have the official count, but I imagine there were close to a hundred people. Quite a few people represented the sponsor companies. The sponsors advertised for hiring new employees, mostly software engineers. On the other hand, I met a few people who joined this venue to talk to prospective employers. Some of the attendees were enrolled in a coding bootcamp to switch careers. I was quite happy to see the community praising their enthusiasm towards the bootcampers. Moreover, I met a few regular tech meetup people after a long time. I used to go to all tech meetups I could find in town before having kids, and I felt great to be among the self-motivated crowd after a long break.

About the event, I was fascinated by how the unconference took its shape. At check-in time, everyone got a couple of forms to write down topics of interest, either as a host or a participant. Everyone could vote for five such topics. I didn’t prepare beforehand. So, I put up a topic that I’m presently curios about, “Writing for Developers”. A handful of people voted for me, but it didn’t make the cut. I found some ideas better than mine and was happy that those got voted to the top. In hindsight, I should’ve proposed the topic of “Why Are You Not Innovating?”. I did an internal presentation on this topic at Cisco and it was generally praised by my colleagues.

My other observation is, between technical and soft-skill related topics, I liked the soft-skill ones better. For example, I found the topics on hiring, choosing a technical vs. managerial career path to be more interesting than the topics such as GraphQL and ReactJS. A few years ago, I’d just choose the technical topics without thinking twice. This is also a pattern in my recent blog posts or reading list.

In the hiring session, I saw a positive attitude towards hiring remotes and treating them as equals. This is a major mindset shift among the community.

In the individual contributor vs. management career path session, the attendee list included both kinds as well as people that had transitioned in either direction. The one take home message I got from this session was, when confused with career choice, individual contributors and managers should take the step to switch roles. And if things don’t work out, it’s totally possible to revert later.

I’m looking forward to the 2020 edition of this event and may even prepare to come up with a good idea for the unconference. If you can, please join us for the next round.

Micro Design Critic: Microsoft Word vs. Apple Pages

MsWordVsApplePages Showing a Screenshot of Microsoft Word for Mac and Apple Pages

This is what you get by default when you open a blank document on both editors. I love that Apple Pages puts a deep focus on the content. If you haven’t used it, I’d recommend trying it out. I know Microsoft Word has a known face, so you’re likely used to all the distractions that sorrounds the content. But, if you can, give Apple Pages a try.

Exception Handling Anti-patterns

confusing road sign

Source: Henry Burrows

Whenever faced with a production issue, I find exceptions to be an extremely useful information source. A careful look at an exeption has often led to quick discovery of the source of a trouble. On the flip side, I have also faced a lot of chaotic debugging sessions because of poor exception handling. Here, I present the common anti-patterns that I recommend fixing while reviewing pull-requests. Most programmers are already familiar with the mechanics of exception handling. Yet, I see these anti-patterns everyday.

I primarily see these anti-patterns to be control-flow or logging related as shown below:

Control-flow Anti-patterns

Unhandled. When an exception is unhandled, if often results in a clueless user experience for the end user as well as the developer.

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def notify
  post.email! #May fail due to configuration, network, or authentication
end

Catch-all. With catch-all errors, it’s often difficult to quickly detect the original problem. For the same reason, the end users don’t get specific and actionable error messages.

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def create
  post.save! #May fail due to database issues
rescue => error
  # handle
end

If-else Exceptions. Exceptions mean something unexpected took place. If-else is used for logical known code paths. For example, when accepting an API request, invalid input data is often a known logical path. Using exceptions for it will trigger false alarms.

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def create
  post = Post.new(params)
  post.save!
rescue ValidationError => error
  log_exception(error)
end

Wrapped Exception. A new exception is raised hiding the original exception. In such cases, if the exception is handled by the caller, critical context information is lost since the orignal stacktrace is no longer available.

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def create
  post.save! #May fail due to database issues
rescue SaveError => error
  raise CustomSaveError.new('Failed to save the post')
end

Useless Custom Exception. Introducing a new exception type when a pre-defined exception suits just fine.

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def create(text:)
  if text == nil
    #Could just use pre-defined ArgumentError
    raise EmptyTextException.new("Text can't be empty")   end
  #...
end

Leaky Handler. Handling an error without cleaning system resources such as file handles, open network connections, can cause cascading system outage.

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def create
  #Will leak this file handle if read succeeds, but write fails
  file = File.open('/some/new.txt', 'w')
  file.write('some text')
rescue FileNotFoundError, FileSaveError => error
  log.warn('...')
  raise error
end

Logging Anti-Patterns

Silent Handler. Makes it very difficult to debug problems.

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def create
  post.save! #May fail due to database issues
rescue
end

Debug-only Handler. Similar to silent handler since most production apps run in non-debug log level.

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def create
  post.save! #May fail due to database issues
rescue SaveError => error
  log.debug "failed to save post #{error.message} #{error.backtrace.join}"
end

Custom Message-only Handler. Some exception handlers only log a custom message leaving the details of the exceptions. As a result, critical information is lost that can be very useful for debugging.

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def create
  post.save! #May fail due to database issues
rescue SaveError
  log.warn "failed to save post"
end

Message-only Handler. Without Stacktrace, it gets very difficult to trace the root of a problem since often times exception handlers wrap a few lines of code.

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def create
  email = User.find(params[:id]).email
  post = Post.find(params[:id])
  comment = post.comments.create!(name: user.name)
rescue NotFoundError => error # Could happen in line 2 or 4
  log.warn "failed to save post #{error.message}"
end

Sneaky Handler. Some exception handlers return nil or a value. The caller can’t distinguish between a successful vs. exception case and fails in subsequent steps.

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def create
  post.save! #May fail due to database issues
rescue SaveError => error
  log.warn "failed to save post #{error.message} #{error.backtrace.join}"
  return null
end

There are times when you intentionally have to use some of these anti-patterns. But those are rare. It’s critical for the developers to think about the information that’d help in swiftly debugging a production problem. As such, developers must avoid the noise and provide all context information for errors to help diagnose potential system problems.

Happy coding.

“Ah, How Good It Is to Be Among People Who Are Reading.”

Rainer Maria Rilke

All creators take a deep interest in the creations of others. All filmmakers watch a lot of movies, all good writers are also the most prolific readers, all artists can talk at length about the smallest pieces of art they have seen.

We, software developers, if we want to claim ourselves as the artists of this craft, we must be prolific readers of code. There’s been no better time as today. We have immediate access to millions of lines of carefully written code out there in the internet. Just like artists of any craft, I’ve had so much fun spending time with my fellow developers that read code for the pure joy of learning something new.

Just had so much fun reading this ruby code today from the Ruby on Rails project:

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class Array
  # Wraps the array in an +ArrayInquirer+ object, which gives a friendlier way
  # to check its string-like contents.
  #
  #   pets = [:cat, :dog].inquiry
  #
  #   pets.cat?     # => true
  #   pets.ferret?  # => false
  #
  #   pets.any?(:cat, :ferret)  # => true
  #   pets.any?(:ferret, :alligator)  # => false
  def inquiry
    ActiveSupport::ArrayInquirer.new(self)
  end
end

The beautify of this rich API is an art. I love it. You may have different opinions. But I hope you find your love of art in code. There’s plenty of art in code out there for everyone to enjoy.

How Am I Developing the People I Support as a People Leader?

After being a people leader at work for the past six years, I’m now going through a phase of introspection. Essentially, I’m trying to understand my own philosophy about people leadership so that I can clearly communicate it to the people that I support.

My most important realization is, people leadership is all about developing people. What I mean by this is, for everyone I’m supporting, I must carefully build a plan that provides them with the opportunities to stay motivated so that they can thrive. With this goal, once I wrote down my understanding of what motivates each of the people I support, it was quite eye opening to see the differences among people. Going through this process, I also realized how unprepared I was in terms of providing them with a clear career path to achieve their best.

If you’re interested, I’ve shared a template of the people development document here.

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Name: ___
Date:___
Current role: ___
Motivation: ___
Upcoming opportunity in the next three months:___
Upcoming opportunity in the next year:___

I consider this to be a living document as people often develop new interests and the opportunities at work change with time. But keeping a clear log of each individual’s career is a great way to establish and manage expectations. You can build this with the the individuals directly and update it when you meet for one-on-one feedbacks. As a lead, when you collaboratively build this, you empower them and build a trusting relationship as you both see how the motivations align with the work.

From the past 13 years of my time in the industry, working for 5 different companies, personally I’ve always felt a little under-informed about how my leaders planned a career development for me. Through my introspection of being a people leader, I realized I didn’t honestly appreciate the need for such clarity among the people I supported. So, I wanted to change it. And found the written document to be a simple yet surprisingly powerful tool to fill this void.

Now, if you’re a people leader, I’d recommend doing this exercise with your people. You’ll be pleasantly surprised by the outcome.

If you aren’t a people leader, you can write it down for yourself and ask your leader to collaborate on it. This way, when you have a one-on-one, you both will have the same reference document to focus on.

Ruby on Rails: Database Migration and Downtime

Recently, we had a production outage for a few minutes due a database migration on one of our Ruby on Rails apps. The deployment went fine through a few stages, but the problem only showed up at the last and the largest stage. This is exactly what happened during the deploy process.

  1. New code was deployed. Restart was pending, so the server was still running old code.
  2. Migrations ran.
  3. One migration removed a column that was used in the old code, but no longer used in the new code.
  4. The next migration was a data migration that inserted one row / user to a table. This was a very slow migration, taking 5+ minutes.
  5. The old code failed because it tried to use a column in the database that was no longer there. To make things worse, the column was referenced at all page loads within the app.
  6. The long running migration didn’t finish because it ran into a timeout.
  7. The servers weren’t restarted because the migration had failed. So, the new code wasn’t served at all.
  8. There was no automatic database rollback to restore the system into a good state with the old code.

The team was able to resolve the issues within the next 5 minutes, but it was the worst system outage we’ve seen in years. For anyone dealing with a large Ruby on Rails app, you can use the following safeguards to avoid such problems:

  1. Do not remove a column from the database while the current code is still using it. Do it at a later release.
  2. When a deployment fails at the migration step, ensure you have a rollback policy so that the system can be automatically restored to a known good state.
  3. Consider data migrations to be a performance problem and always test the migrations with relaistic load before production release.
  4. If possible, run your data migrations seprately from schema migrations so that you don’t incur deployment delays for optional new data.

What I Learned From Grad School About Innovation?

Rainy Window Src: Claudia Dea

Most problems are solved inefficiently. Innovation follows when a problem is researched first.

I spent a fair amount of time in grad school. First, sixteen months on my MSc, and then another forty eight months on my PhD program. Also, I worked as a pro software engineer for 20 hours/week during my MSc days and then full-time during the PhD days. It was quite an undertaking, but I survived and now claiming my bragging rights :-)

This post is about a general problem-solving approach that I internalized as the most valuable lesson from my grad school days. I hope you find it useful. I’ll try and explain the concept using a personal story. Here you go.

Recently, I was discussing plans for the near future with my wife, Shahana. She’s an engineer. In the past, Shahana worked in the telecom industry as a network planner for a few years. Then, she decided to take an extended maternity leave to stay with our two little kids, Shopoth and Shera. Now, honestly, she’s had enough and seriously contemplating a return to work. Except, she’s unsure about what career to choose that she’d really enjoy.

Given this vague problem of finding a new career, she felt lost for a while. As a true supportive husband, I decided to be her man and gave her an earful!

Silly jokes apart, we decided to set the context first by asking and answering the following questions:

  1. Why is she looking for a new career?
  2. Why not remain in the old career?
  3. What new career options exist?
  4. Where are the opportunities?
  5. Who knows more about those?
  6. How does she get a job in the preferred area?

After spending a few days of research, she developed a very clear understanding of the problem and the initial vagueness of the situation was mostly wiped clean resulting in a few clear constraints. From a job portal, Shahana then listed available job requirements from a number of open positions matching her criteria. After consolidation of the requirements, the gap was clear. It was obvious that she’d need to develop essential new skills to qualify for the jobs. As she acquires the new skills, she already knows the evaluation. If this doesn’t work, she can repeat the same process to either improve her chances or choose an alternate career path entirely.

This was a direct application of the problem-solving framework that I learned from grad school. Here’s a nerdy version of the framework:

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  Given a problem
    1. Ask the Wh questions -> list constraints
    2. Research -> list existing solutions
    3. Is the problem already solved? -> If yes, stop
    4. Innovate, fill in the gaps.
    5. Evaluate

In real life, most problems are deceptive. We think we already know the best solution based on our past experience and go straight to #4 leaving all other parts out. Even if going straight to #4 is actually a wise move, it only becomes an innovation with a tiny impact, as it doesn’t become available at step 3 for others to leverage.

A large number of problems can be solved at step 3, by leveraging a solution or a mix of multiple solutions that already exist. Even when problems get past step 3, it’s highly likely that the gap is smaller than the extent of the whole problem. So, an innovation can focus only on solving the gap, which offers speed and intelligent reuse.

This post is so prosaic already. But if you’re still with me, I’ll make it even more textbook like by giving you a couple of practice problems. Go ahead and apply my 5-step problem solving approach:

  1. Jane is a musician, a prodigy so to speak. She’s been invited to talk about music as a therapy. She’s not good at speaking, but this is a big opportunity. What does she do?
  2. Mike is a young startup CEO. He’s very good at business and technology. He needs a lawyer to take care of the legal matters. How does he hire the best lawyer possible?