Category Archives: Back-End

Monitoring a Spring Boot app in Kubernetes – What I learned from Devoxx Belgium 2019

This November, accompanied by 3 other members of the Shop team, I attended Devoxx Belgium 2019, held in Antwerp, Belgium – the birthplace of Devoxx and most populous city of Belgium. Devoxx is a developer community conference series started in 2001 which quickly grew to become one of the largest vendor-independent Java conferences in the …

Building Large Kubernetes Clusters

Introduction LINE supports its developers so that they can fully focus on development. This was the background of implementing Nucleo, LINE’s in-house Kubernetes-based service, taking care of infrastructure on behalf of developers. Nucleo currently services 800 apps with about 4,000 pods. The number of apps is growing by the minute. All the workloads are being managed …

Verda at CloudNative/OpenStack Days 2019 (2/2)

This blog post is the second part that continues from Verda at CloudNative/OpenStack Days 2019 (1/2). In the previous post we took a look at the overall ecosystem of Verda. In this post I will explain our network side challenges and how we optimized and improved Verda to overcome those challenges.

LINE’s Verda Network designs:

Lets go through the 3 transitions of LINE data center networks.

  1. L2-based network backed with upstream solution using Linux bridge
  2. L3-only flat network: Developed by LINE OpenStack engineers
  3. L3 Base Overlay network: Developed by LINE engineers

Verda at CloudNative/OpenStack Days 2019 (1/2)

Ever wondered what LINE uses internally for infrastructure management? If yes, then you came to the right blog post.
Recently at CloudNative/OpenStack Days Tokyo, LINE presented on its OpenStack cloud project called Verda.

This article is going to be a series of two blog posts which provide a summary of the entire Verda ecosystem:

  1. Verda at CloudNative/OpenStack Days 2019 (1/2)
     → Bird’s eye view of Verda
  2. Verda at CloudNative/OpenStack Days 2019 (2/2)
     → LINE’s network design to meet private cloud user requirements

In this blog post, we’ll be looking through a bird’s eye view of LINE’s OpenStack project Verda and introduce you to the entire OpenStack ecosystem that LINE has. Without further ado, let’s begin!

Developer interview with Trustin

Q. Hello, Trustin! Let’s start with a brief introduction of yourself. A. Hi. My name is Trustin, and I’m currently involved in open source development of Armeria and Central Dogma at LINE. Before I joined LINE, I worked at Twitter, responsible for the maintenance of Netty as well as the development of new features and upgrades to next versions. Q. You seem to …

Cutting through the smog: making an air quality bot with Haskell

Short and long-term exposure to air pollution can result in significant health problems. When air quality is considered unhealthy we should avoid certain activities, which poses a question that bears asking: how can we get notified when air quality is poor? This post is an attempt at solving this. In this tutorial, I want to …

Troubleshooting Data Engineering Software

Hello, I’m Keiji Yoshida. I currently work as a data engineer at LINE Data Labs. In this posting, I’d like to share a few cases on data engineering software troubleshooting: Apache Hadoop YARN ResourceManager failover Apache Hadoop HDFS NameNode failover Apache Zeppelin Notebook scheduler issue Apache Zeppelin deadlock issue Apache Spark SQL performance issue Troubleshooting failover issue in Apache Hadoop …

Making a Flex Message with LINE’s Go SDK

Hi there, this is @sugyan (Twitter, GitHub) from LINE Kyoto office. This was first time for me to experience  Kyoto’s Summer, and boy, was it really hot or what!? (The original post in Japanese was published in August 2018.) In June 2018, a new message type, Flex Message, was introduced in the LINE Message API, allowing more complex …

Developing server-side with Kotlin & entering Clova Skill Awards

Hello fellow readers! We are, Kagaya, working on the LINE GAME Platform development team and Akira, on the LINE LIVE Android app development team. Have you ever used Kotlin? Kotlin is a static-typed programming language that runs on JVM, and has been developed by JetBrains, well-known for making IDEs like IntelliJ and Android Studio. Kotlin …

Redis Lua script for atomic operations and cache stampede

Hello, this is Kagaya, a member of the LINE GAME Platform development team. It’s nice to be back after writing a post on Lazybones (Japanese post), in 2016. Redis and LINE GAME Platform The LINE GAME Platform uses Redis — in-memory no SQL database — for its main database, mainly for cache. For instance, we are using …