A presentation at Hackajob by Nikita Lohia
Lost production and don’t know why? Track your code releases! Nikita Lohia Senior Engineer, Financial Times @NikitaLohia HOLDING SCREEN - click once at start for timings!
Lost production and don’t know why? Track your code releases! Nikita Lohia Senior Engineer, Financial Times @NikitaLohia HOLDING SCREEN - click once at start for timings! Thank you for joining us today. I am Nikita and I am a senior engineer at the FT. I want to talk about how we track code releases at the FT.
https://medium.com/ft-product-technology/making-the-case-for-cloud-only-92f382ff8dd9 The Financial Times is one of the world’s leading business and financial news organisations. As of 2020, we are a fully cloud hosted company. Mark Barnes, my colleague at the FT has written an excellent blog on our journey to Cloud-only.
The Problem When something goes wrong, the first question you want answered is - what changed? @NikitaLohia At the FT, we have around 500 microservices being managed by multiple different teams. These teams work in different timezones, releasing code at different times during the day. At any point in time, we want to be able to consistently and confidently answer the question - what changed recently and if that change causes a disruption how quickly can we fix it? This is not only important for the teams developing these services, but also important for our Operations team - watching over our entire estate 24/7. How can they associate an alert firing to a recent release? So we set ourselves a challenge - we need to track all code releases happening in our tech estate.
Our first attempt .. @NikitaLohia Our legacy Change Request API(CR API) Change and Release Management at the FT was not a new concept. Our legacy Change Request API, fondly called CRAPI (/ˈkræpɪ/) was tracking releases, both automated and manual, and storing them in a third party change management tool. There were a few reasons why it wasn’t a huge success and why it didn’t quite work anymore….
Our first attempt .. [redacted] @NikitaLohia Our legacy Change Request API(CR API) Legacy CR API was written in Java around 5 years ago, people who wrote it had long moved on. No-one in the team quite understood it anymore. It was not easy to use and very error prone. Users also needed to specify a start and an end date for the change, thus needing to call the API twice.
Our first attempt .. @NikitaLohia
The journey… Lets go through our journey from migrating from this legacy , rarely used CR API to a fully integrated, automated release log process and the lessons we learnt along the way.
Learn from the past To start off - we did some digging .. We spent some time talking to the handful of people who were using legacy CR API. We asked them what about it works and what does not, what can we use and what can we throw away..
Learn from the past ● Make it simple ● Make it useful ● Make it reliable ● Make it fast Or… “SURF” :) @NikitaLohia We summarised all of that feedback and consolidated that into these 4 targets. Since we love us some acronyms, why not .. lets call it SURF :)
Learn from the past ● Make it simple @NikitaLohia So - how did we address these goals? How did we simplify sending Change logs at the FT?
Learn from the past - Make it simple For our end users, we reduced the amount of work they need to do @NikitaLohia Legacy CR API depended on its users for a lot of information. We decided to make the service, now rebranded as Change API, do the work. Instead of requiring 10 different fields, we asked Change API users to only provide 3 mandatory values :
Learn from the past - Make it simple @NikitaLohia
Learn from the past - Make it simple @NikitaLohia Our legacy Change Request API(CR API) During our user research, not many users saw the benefit of logging the start and the end date for a release. Rightly so, since with microservices, most of the code releases only take a few minutes. When designing change API, we removed the need for the users to tell Change API the start date of the release. So instead of having to make two separate API calls…
Learn from the past - Make it simple @NikitaLohia they only need to call it once, after the change was done.
Learn from the past - Make it simple For ourselves, we decided to rewrite it in a language we understood @NikitaLohia Also, Since no-one in the team had a lot of experience with Java, we decided to rewrite it in JS to better support it.
Learn from the past ● Make it simple ● Make it fast @NikitaLohia How did we solve the problem of avoiding delays on team’s deployment pipelines?
Learn from the past - Make it fast We made API calls asynchronous @NikitaLohia We made Change API async. As long as the user was sending Change API the 3 mandatory fields and it was in a valid format, Change API would almost immediately send an “Accepted” response. An invalid client request would return a “bad request” instead. Rest of the release log processing happened asynchronously. As far as the user is concerned, the Change log request is completed within milliseconds, if that. By doing just these 2 things, we had already solved half of our problems.
Learn from the past ● Make it simple ● Make it fast ● Make it reliable @NikitaLohia How did we build trust in Change API ?
Learn from the past - Make it reliable Don’t throw server side errors @NikitaLohia Another important lesson we learnt was to ensure that server side errors do not cause a bad user experience. We decided to simply not throw any server side errors. There wasn’t anything a user could do about them anyway. They would just get annoyed at us for breaking their pipeline. We instead, silently log all the errors and let the request complete successfully. It was upto Change API to handle retries under the hood.
Learn from the past - Make it reliable Don’t change how user interacts with it @NikitaLohia Over time, we made a LOT of improvements and modifications to Change API - ALL without changing user interaction with it. This provided our users some much needed assurance that adding Change API to their deploy pipelines will not stop their deployment, even in case of an error.
Learn from the past ● Make it simple ● Make it fast ● Make it reliable ● Make it useful @NikitaLohia And finally - how did we highlight the benefit of Change API?
Learn from the past - Make it useful Real-time notifications [redacted] of relevant change logs [redacted] [redacted] [redacted] [redacted] @NikitaLohia Legacy CR API didn’t get a lot of adoption because our engineering teams did not see any benefit in it. We gave Change API users the ability to get notifications of their releases.. in real-time. All production releases would, by default, go to a single slack channel. A user could also provide a Slack channel of their choosing and Change API would dutifully send a release notification to it.
Learn from the past - Make it useful @NikitaLohia We went from having to manually inform people that a release is happening… Before Change API
Learn from the past - Make it useful [redacted] @NikitaLohia .. to an automated notification model, where Change API would send release logs automatically on Slack. It looks very bare bones now, but trust me , it gets better :) Change API MVP(Minimal Viable Product)
Walk before you run In other words, start small.
Walk before you run Choose your early adopters carefully @NikitaLohia Change and Release Management is big topic. If you think about it, external auditors, compliance team, dev teams, Project Managers, and Operations support team: they are all potential users of Change & Release Management We picked a handful of engineering teams from different parts of the business using Github and CircleCI as our early adopters since they already had a deployment pipeline in place and we simply had to hook Change API into it.
@NikitaLohia Change API MVP In its infancy, all change API did was accept a valid JSON payload which sent a message on Slack upon successful execution. Lets break this down a little…
@NikitaLohia Change API MVP We asked teams using CircleCI to add a single POST request to their circleCI workflow. This request would contain a JSON body and an API key header. This request would first get authenticated by our API Gateway platform which would check the validity of the API key. If the authentication fails, the user gets an authentication error.
@NikitaLohia If a request is successfully authenticated, a lambda function, called Validator here would validate this request. - if the validation fails, it would send a 400 bad request to the user, ending the user journey. If the validation is successful, - It would immediately send a 202 response to the user, ending the user journey. Change API MVP
@NikitaLohia Async, the lambda would then also write to a data stream, in our case, AWS Kinesis… Another lambda function, called Slack consumer here, would then read this payload and send a message to slack. Change API MVP
@NikitaLohia Change API MVP I mentioned earlier about giving users a consistent and reliable experience with Change API - I cannot stress the importance of this enough. Reliable behaviour of Change API was what drove its adoption rate initially. It was fire once and forget. Through all the changes that came later, this part of change API was never modified. Note the striking absence of a database. That came later too… The idea was that we could simply add or remove more features to our steady stream of real-time release logs to continuously BUT iteratively improve Change API. Within 3 months of starting this project, and a small team of 3 engineers, we produced a Change API MVP. It was a huge success.
Step changes We expanded our early adopters list and we kicked Change API development into high-gear.
@NikitaLohia Change API now We integrated Change API with other services. This is what Change API architecture looks like now. Allow me to highlight some interesting areas..
@NikitaLohia Change API now We added “enrichments”.. A lambda function, called enricher here would interact with the GitHub API to fetch code commit and Pull Request information. The enricher would also talk to our system registry API and fetch additional information about the service being released. we added many such enrichments… It’s worth reminding you here that all this happens async. The user journey has long ended after sending a valid request payload .
[redacted] [redacted] [redacted] [redacted] @NikitaLohia Search and view capability of historical releases We also build a change log database. This is Change Viewer which allows users to search for historical releases logged by Change API. It allows filtering by specific days, or system codes for example.
Change API MVP… [redacted] @NikitaLohia Lets remind ourselves what a release notification looked like before..
Enrichments Auto-converts Github username into full AD username Auto-links to the troubleshooting guide for the service [redacted] @NikitaLohia Auto-links to the code commit which triggered this change Change API notification now And now, after all the enrichments this is what a Change API release notification on Slack looks like.. Thanks to the enrichments, the message contains the full name of the person who made the change, along with a link to the code commit, and a troubleshooting guide for the service, just in case the release causes a downtime.
Enrichments - BONUS! [redacted] @NikitaLohia We are now even logging changes made to DNS which until a couple of years ago, was a pipe dream !
Enrichments - BONUS! @NikitaLohia Any sys admins or devops engineers here? You probably have seen this Haiku before.. Would anyone care to guess how many DNS records does the FT have? Think of a number in your head… Last I checked, we had upwards of 6500 DNS records ! From my experience, if what’s wrong is not obviously evident - it really is always DNS
Enrichments @NikitaLohia We also integrated Change API with our monitoring platform. This screenshot illustrates a banner on a service’s monitoring page if it was released within an hour. Now, we could immediately co-relate a service monitoring alerting with its recent release. Heimdall, our monitoring platform
@NikitaLohia Change API adoption gradually increasing Here is a graph showing the number of Change API events gradually increasing over time. The dotted line here shows legacy CR API usage. We decommissioned the legacy API soon after rolling out Change API fully. Dare I say it? we surfed our way to the top :)
Use behavioural science to drive change All through the development of Change API - we were using behavioural science to nudge people towards it..
Use behavioural sciences - Nudges @NikitaLohia Nudges, once you are aware of them , are everywhere. It is a subtle hint that encourages you to make a certain decision without forcing you. Take this UberEats email for example, its not asking me to order something from the app directly. Rather, its encouraging or “nudging” me by trying to remind me I still have a discount available and I should use it …
Use behavioural science- Nudges @NikitaLohia Change API dashboard A few nudges we used to encourage more teams to use Change API was to start a little bit of a healthy competition. We all love a competition, don’t we ! We told teams, did you know that this other team made 50 code releases in the past week? Would you like to find out how many your team did? We created a dashboard to get people talking about Change API. At the FT, we clock anywhere between a 100 ~ 150 daily releases !
Use behavioural sciences - Make it default @NikitaLohia A default nudge is the most powerful nudge. As humans, we tend to be inherently averse to making decisions, even if we know that they are good for us. We tried to remove all blockers to Change API adoption We wrote verbose documentation with step by step instructions on how to integrate Change API with different deployment pipelines.
Use behavioural sciences - Make it default https://circleci.com/orbs/ @NikitaLohia We wrote some tooling. Since a majority of our teams favour CircleCI we created a Change API Orb which would allow engineering teams to use YAML instead of bash and curl commands in their config files to integrate with Change API. This is what an orb config looks like. Orbs, for people who don’t know, are an easy way to create reusable yaml configs in CircleCI.
Use behavioural sciences - Make it default Src: https://thesaurus.plus/antonyms/secondment @NikitaLohia We encourage secondments at the FT - i.e. people temporarily take a break from their home teams and work with other teams in the department to either learn a new skill or help other teams up-skill on a particular tooling or technology. We used secondments to integrate Change API into hundreds of repos !
Use behavioural sciences https://skillsmatter.com/skillscasts/9858-nudge-theory-influencing-empowered-teams-to-do-the-things-that-matterto-you-sarah-wells @NikitaLohia There is an excellent talk by my colleague Sarah Wells who talks about Nudge Theory in greater detail. She also talks about the EAST framework which can be a really good guide to influence behaviour.
In summary… So, to summarise Hopefully I have managed to convince you that we solve really interesting problems at the FT , and in a really fun way !
We ended up with some really interesting data.. @NikitaLohia https://medium.com/ft-product-technology/the-advent-of-change-api-8dae0f95245e Along with the capability to consistently and confidently be aware of what changed in our microservice estate , we were able to answer some really interesting questions like “How has the pandemic affected our code releases?”, and “Do our developers prefer a specific time or day to push changes?”
@NikitaLohia Even during the first peak of the pandemic back in 2020, we were pushing out code, business as usual.. Monthly code releases
@NikitaLohia And yes… we also definitely do releases on a Friday ! :) Daily code releases
Thank you! ● https://medium.com/ft-product-technology @NikitaLohia
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