Report on Prometheus Casual Talks in Tokyo and then toward PromCon 2016

Introduction

Hello, my name is Wataru Yukawa. I work at LINE as a data engineer.

As a data engineer, my daily duties include using Fluentd to collect logs, Hadoop to accumulate, and Hive to aggregate and analyze logs. Our Hadoop cluster is medium-sized, consisting of 40 units and approximately 370TB of DFS used space. Data from LINE family apps is smaller compared to the LINE app. While it’s nowhere near large enough to be considered as big data, it still has many types of different data, Fluentd tags, and over 400 Fluentd processes due to the various LINE family services tied to it. The Fluentd data flow amounts to 150 thousand messages per second during peak times.

Introducing the LINE Game AirBorne DataCenter

Last time I posted an article titled, “Analyzing Large Amounts of Security Data with Spark, Mesos, Zeppelin, and HDFS.” Today I will introduce how LINE applies cloud and stream processing technology to perform near-real-time processing on game data detected by AirArmor1.

1: AirArmor is a security solution for mobile games developed by LINE.

AirBorne DataCenter & Mesos (with DC/OS)

To analyze security data, we built our own system named AirBorne DataCenter. The system uses Apache Mesos as its base framework. And to process big data efficiently, the system implements open source components such as Kafka, Spark, Elasticsearch, Hadoop, Zeppelin, and Spring.

Circuit breakers for distributed services

Hello, my name is Ono and I’m a LINE engineer. In this blog post, I’d like to talk about “circuit breakers” which we use with our LINE servers.

What is a Circuit Breaker?

The backend server systems for various web services and apps including LINE consist of networks that have several services connected with each other through APIs and RPCs.

What would happen if one of these networks suddenly failed to respond? The downed services would be blocked until they time-out, and all other services that rely on the blocked service would start a chain reaction of failures. If no one has been keeping an eye on the entire network, it will take a long time to figure out which service is the root cause.

LINE Developer Day 2016

Hello everyone. My name is Kushii, and I am in charge of organizing conferences at LINE.
I am pleased to announce that LINE Developer Day will be taking place once again this year.

At the event our engineering team plan to share some of the experiences, the technical challenges that exist in Japan and overseas, and introduce our latest products directly to you. Security-related topics, BOTs, and other themes will be explored during our individual sessions to explain how LINE strives to overcoming the various challenges ahead.

Event Summary

Date/Time: September 29, 2016 from 10 a.m. to 6:30 p.m.
Place: Shibuya Hikarie, 9F, Hikarie Hall
Invitees: Application and web engineers
Admission: Free
After-Party: To take place in the Hikarie Hall after the event

How to provide stable “Loves”

Hello, my name is Moznion and I’m part of the team working on LIVE: a video-based social media service that connects stars and celebrities to their fans.

On LIVE, users can watch their favorite stars participating in programs or performing concerts all in real-time. LIVE is currently available on iOS/Android and on PC web browsers, and quickly gaining popularity.

In this blog post, I’d like to explain how we handle large amounts of consecutive requests sent on LIVE.

Introduction

Fukuoka office, reopened with a whole new look

Hello, my name is Kushii. I work in the development department in Japan and I’m in charge of promoting technology events at LINE.

LINE has quite a few development offices worldwide where many engineers write code every day. We have offices in Tokyo, Fukuoka, Fukushima in Japan and also in Korea, Taiwan, and Thailand.

The Fukuoka office was relocated recently, and I think this is a good opportunity to introduce the brand new, upgraded working place for our engineers.

The new office is located in the JRJP Hakata building, directly accessible from Hakata station. When you first set foot in the building, the LINE Friends characters greet you at the entrance.

The Road to Releasing LINE Trial Bot SDK

Introduction

Hello, my name is Matsuno and I work at LINE.

LINE BOT API Trial accounts were announced a few days ago, receiving a warm welcome from developers all over the world. Previously only available to developers working at companies who were under contract with LINE, now any individual developer can freely start developing their own project with their own LINE bot account.
In this post, I would like to talk about why we decided to start development on a LINE BOT API Trial account SDK and how we released it in less than a week.

Why the Bot SDK was created

As soon as LINE BOT API Trial accounts were announced, many of our own LINE engineers started developing for them. Which is when we began thinking…
What’s the most difficult part about creating a bot with this API??

try! Swift Presentation Report

Hello everyone, my name is Inami (@inamiy) and I’m an iOS software engineer at LINE.

A Swift developer conference titled “try! Swift” was recently held in Shibuya, Tokyo from March 2 to March 4. LINE was a gold sponsor of the event, which was a gathering of over 500 people (30% of which were from overseas). There were many female presenters in the event as well, making it one of the most diverse gathering of developers I’ve ever seen; the likes of which I haven’t seen in any Swift/iOS study group! I was offered a chance to present at the event about “Parser Combinator in Swift”, a functional programming method.

Open-sourcing Armeria

Armeria is an asynchronous RPC/API client-server implementation built on top of Java 8 and Netty that went open-source last November under Apache License 2.0 by LINE Corporation. Its primary goal is to help engineers build high-performance asynchronous Thrift clients and servers that use HTTP/2 as a session layer protocol, although it is designed to be protocol-agnostic and highly extensible (for example, you can serve a directory of static files via HTTP/2 and run Java EE web applications).

In this post, I’d like to focus on the steps that were taken to open-source an internal project rather than the technical aspect. If you are interested in the technical details of Armeria, you might want to check out the following slides presented last February during the 14th LINE Developer Meetup:

Multi-Threaded Parallel Processing for Physics Simulation in Cocos2d-x

Hello. My name is ST and I develop mobile games here at LINE. In this post I would like to talk about the multi-threaded parallel processing method we are using with Cocos2d-x, the leading mobile game engine. I will go into more detail about how we improved upon the existing single-thread structure and enhanced performance using multi-threaded physics calculation.

Multi-Threaded physics calculation parallel processing architecture

Before we move on to the multi-threaded physics calculation parallel processing structure, we should take a look at the existing single-thread Cocos2d-x update loop.