Tag Archives: 2021

Gerrit: 2021 in review

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Yet another year has passed for the Gerrit Code Review project with many challenges posed by the COVID-19 pandemic, new exciting releases, and the most popular Gerrit User Summit with the largest audience ever in its 12 years of history.

2021 in numbers

  • 93 registered attendees to the Gerrit Virtual User Summit 2021, connecting from 56 companies over 17 countries, 14 talks showcased by 15 presenters over 2 days
  • 1 Gerrit Contributors’ Summit
  • 35 releases of which 2 major versions (v3.4.0 and v3.5.0.1) and 33 patches
  • 107 contributors from 32 organizations, merging 4763 changes to 84 projects

The Gerrit Code Review community has shown resiliency during these difficult times, with outstanding participation in the events organized during the year, all remote and lacking the much-needed face-to-face interaction.

  • Commits: -26%
  • Projects: -16%
  • Contributors: -30%
  • Companies: -41%
  • Average changes/contributor: +10%

The engagement has paid its toll after two years of pandemics with fewer organizations willing to invest time in contributing to Gerrit, possibly also impacted by the uncertainty of the future. 2021 has also been the first whole year of the project without David Pursehouse, one of the Gerrit project’s top #3 contributors. He was used to contributing 1.5k changes per year, which would alone easily justify the drop observed.

On the bright side, the contributors that continued over the year 2021 have shown an increased commitment as the number of active projects and commits has dropped less than the contributors, increasing the change/contributor rate compared to 2020.

Major organisations contributing to Gerrit in 2021

Google is confirmed to be the leading force of the Gerrit Code Review project, with over 62% of the changes merged, while GerritForge continues to be the #1 top contributor from the rest of the community. There are a couple of pleasant special surprises from the contributors.

  • Wikimedia Foundation confirmed to be the #2 top contributor from the community, all provided by Paladox who has been awarded Gerrit Maintainer in November.
  • SAP continues to be a strong contributor, just below Wikimedia Foundation, with Thomas being awarded Gerrit Maintainer in November.
  • Qualcomm is back on the shortlist of the top maintainers, with many new names in the list of contributors, well done!

Top-ten projects with major activity in 2021

  1. gerrit (2,903 changes)
  2. plugins/code-owners (447 changes)
  3. jgit (287 changes)
  4. plugins/task (83 changes)
  5. plugins/multi-site (57 changes)
  6. aws-gerrit (44 changes)
  7. modules/cache-chroniclemap (40 changes)
  8. plugins/checks (39 changes)
  9. plugins/high-availability (39 changes)
  10. plugins/replication (38 changes)

The first surprise is that the code-owners, the emerging star of the Gerrit plugins, received a massive investment of effort from Edwin (Google), who contributed 89% of the changes to it. The code-owners plugin has also been presented at the Gerrit Virtual User Summit 2021 and attracted the community’s attention.

The second surprise is the decline in contributions in the jgit project during the past two years: from 820 changes/year is now down to 374 changes in 2021.

Task is now the #2 plugin project in terms of merged changes in 2021. Qualcomm keeps the project’s full ownership with 98.9% of changes in 2021.

GerritForge confirm their commitment to improving Gerrit Multi-Site, as its plugin is the #3 in terms of changes merged in 2021.

Aws-gerrit is a relatively new project, presented less than two years ago and contributed by GerritForge, who contributed over 99% of the changes. It confirms to be a very active project that has helped the Gerrit Code Review open-source project deploy and test well-known “recipes” of infrastructure setups and see how Gerrit performs and works on those. Many bugs have been detected before the release and identified by the aws-gerrit project and CI integration.

The cache-chroniclemap module confirms to be very active in 2021, with 40 changes all provided by GerritForge. This relatively new module allows existing Gerrit setups to increase the overall performance of all persistent caches, which are vital in reducing the REST-API latency across all Gerrit features.

The checks plugin was deprecated back in 2020. However, it still shows significant changes and investment from Google in supporting the new Gerrit checks-API and UI. However, the rate of contributions is in stiff decline, down from the 324 changes in 2019 when it was still an actively developed project.

The last two plugins projects in the top tens are the replication and high-availability plugins, which has received major contributions from Qualcomm, GerritForge, Google and Ericsson.

Top events in 2021

The Gerrit Code Review community abandoned the idea of a face-to-face event in 2021 because of the continued global pandemic of COVID-19.
Instead, there were two separate virtual events for sharing the news of what is happening on the platform and the expectations from the community.

Virtual Gerrit Contributors’ Summit – 9th of June

The summit was organized by the Gerrit Community Managers and had an amazing audience amongst the contributors. The presentations showed what different teams are working on and reported into the summit notes:

Gerrit Virtual User Summit 2021 – 2-3 of December

It was the first experiment of an entirely Virtual User Summit of the Gerrit Code Review project history. The challenges were multiple, including the limitations of allowing up to 100s of attendees, shortening the overall time to 3h x 2 days, and still allowing some interactions between the audience and the presenters. After two years of silence, we have finally received some user stories of using Gerrit in the wild.

The Summit has received vast overall positive feedback and rated 7.9/10, making it a fantastic achievement. The quality and interest of the talks were scored even higher, reaching 8.2/10.

The talks have been fully recorded and published on the GerritForge TV channel:

It was definitely a lot of information and sharing, which showed that the Gerrit Code Review open-source project is alive and active more than ever.

Gerrit features highlights in 2021

Gerrit Code Review has major innovations developed and decisions made over 2021. See below a short recap of the ones that represent a turning point in the evolution of the Gerrit open-source project. Some of them are considered breaking changes and, therefore, need careful analysis and a planned upgrade path.

Speed up of Gerrit upgrade from v2.7 to the latest version

2021 has seen a significant increase in the cooperation and contributions of Qualcomm to the rest of the Gerrit Code Review community, focussed on the speed-up of the Gerrit upgrade process from v2.7 to v3.5.
The contributions and cooperation have brought many improvements to JGit and Gerrit and will allow many more companies to migrate faster and smoother than ever before.

Goodbye to Java 8

From Gerrit v3.5 onwards, the source code and binaries of Gerrit Code Review won’t be compatible with Java 8 anymore.

JSch SSH library is completed removed from Gerrit Code Review

The quirks and obsolescence of the JSch library has cursed Gerrit’s destiny for years. Thanks to Thomas Wolf (Paranor) JGit moved away from it and rebuilt all its Git/SSH stack on top of Apache Mina. That has allowed to remove the JSch library from the Gerrit dependencies and used the Apache Mina SSHD client stack instead.

ElasticSearch is removed from Gerrit Code Review

On the 2nd of February 2021, Elasticsearch B.V. changed its license model and abandoned the Apache 2.0 open-source license for the new versions of ElasticSearch v8 and over.

Gerrit cannot include or require any commercial product not released under one of the open-source licenses allowed by the project. The ElasticSearch backend has not been widely used in the community anyway, based on a recent survey sent to the community therefore the ESC decided on the 3rd of November that the ElasticSearch backend will be removed from Gerrit core and moved into a libModule.

Submit Requirements waving goodbye to Prolog

The Gerrit Code Review project does not use anymore Prolog rules for the submit rules of the project from the 16th of December. The support for Prolog-less submit rules is now mature and it will be part of the forthcoming v3.6 release in 2022.

What’s coming in 2022?

The future of Gerrit Code Review is bright and full of innovative ideas and improvements on the overall development and CI/CD lifecycle. With the forced remote working of millions of developers worldwide, more and more companies are looking on how to make remote interactions more useful and fruitful, reducing frictions and making the workflow smoother and faster more than ever.

Stay tuned and keep on using and contributing to Gerrit Code Review, one of the most innovative and productive platforms for code review and collaboration.

2021: What’s cooking in GerritForge

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Our mission is to improve the Gerrit Code Review platform, with the Open-Source community and in full transparency. Everything we do is published, is open, can be analysed and scrutinised by any member of the community at any time.

In this article, we are publishing what GerritForge is planning to do in the forthcoming 2021, a pivotal year that will see the entire world bouncing back and looking at the future of Technology with a different light.

Goal: cloud-native Gerrit Code Review

Since our initial post in 2019 about our plans for the future, we have been making steady progress toward a unified global Gerrit platform, highly available and distributed across the globe. Since then, a lot of steps have been made, many of them happened in 2020.

Thanks to SAP and GerritForge, we have now two Open-Source standard deployments on the Cloud:

  1. K8s-Gerrit – Helm-charts for deploying Gerrit Code Review to a Kubernetes Cluster (beta)
  2. AWS-Gerrit – CloudFormation templates for creating a production-like setup of Gerrit HA and Multi-Site to ECS on the AWS platform.

Even if Gerrit can deployed now into a Cloud environment, that does not mean that Gerrit is cloud-native. The main requirements for making an application cloud-native is captured by the 12-factor principles. We will be tackling some of them in our 2021 roadmap.

Cloud-native backing services

Thanks to the advances in the Gerrit Multi-Site plugin in 2020, it is today possible to have a geographically distributed cluster of Gerrit servers around the globe. The services that are needed for coordinating the events across Gerrit nodes and ensuring global consistency are:

  1. Event-broker (Kafka)
  2. Global ref-db (Zookeeper)

The price to pay for a global Gerrit Multi-Site is currently quite high, because one may argue that actually managing a cluster of Kafka brokers or Zookeeper nodes can be even more challenging that managing Gerrit itself.

A cloud-native application should be fully independent from its backing services and be opened to swapping one specific implementation (e.g. Kafka) with a serviced off-the-shelf solution (e.g. AWS Kinesis, GCP PubSub).

As GerritForge we are joining the forces with the Gerrit Code Review community in 2021 for refactoring the Gerrit Event system and making it more Cloud-native, using open-standards for representing and publishing events across the network.

The immediate actions are:

  1. Build a new protobuf-based events representation in Gerrit v3.4
  2. Abstract the serialisation of events from their transport
  3. Implement different events brokers and listeners, other than the Kafka. (e.g. NATS)
  4. Provide a AWS Kinesis-stream event broker connector
  5. Provide a GCP PubSub broker connector in cooperation with Google

Gerrit performance across sites

Making a stateful application like Gerrit Code Review a truly cloud-native and distributed platform brings some challenges in terms of latency and performance.

The current Gerrit Multi-Site architecture still relies heavily on the traditional (push) replication plugin, which has been working nicely for over a decade for a Gerrit primary/replica setup. When the repository size increases and the need for global consistency becomes more stringent, relying on a traditional async git push is not enough anymore: you need a lot more tools at your service.

GerritForge has introduced in 2020 the pull-replication plugin, which enables to invert the replication logic: instead of having one Gerrit server to push everything to everyone else, you just tell the other nodes of what’s new in the repository, and it will be their responsibility to fetch only the stuff that has changed.

In 2021 we are going to improve the plugin with native JGit client protocol v2 support and features that will go well beyond the limits of the git protocol:

  1. BLOB and ref-update on remote git pulls. The remote Gerrit node can receive directly the content of what has changed, directly in its payload. That allows to avoid the expensive git pull operation especially for NoteDb related updates.
  2. Event broker integration for git pulls. Instead of relying on REST-API, the pull replication plugin can produce pull replication events in the event broker.

The implementation of those improvements will allow to drastically reduce the incidence of the traditional (push) replication activity and make the Gerrit user experience more seamless across sites.

CI integration

Integrate Gerrit in more seamlessly with other cloud-native services, such as CI/CD. Gerrit v3.4 is planning to introduce a brand-new style of integration which would not require anymore any 3rd party adaptation or API support.

GerritForge is committed to endorse this new module and allow Gerrit v3.4 to be fully connected with Jenkins on day-1 and potentially other cloud-based CI/CD systems.

Git reftable: provide more performance for mono-repos

GerritForge will experiment and test at scale the introduction of Google’s Git reftable, already included from Gerrit v3.2 onwards, to assess its performance impact on large mono-repos, with hundreds of thousands of refs.

Have your say on Gerrit future

This is our GerritForge shopping list for 2021, wide open for discussion, contributions, amendments, and voting.

Why should you care about what we do? Simply because the union of intents and cross-pollination of ideas make the Open-Source products and community stronger: if we join forces in building a solution that is a common interest for all of us, we will all benefit from it.

Your feedback is welcome and precious, feel free to have your say and comment this post with your ideas, likes and suggestions on how to make them even better.

The GerritForge Team.