LINE Developer Day 2016 recap

Hello, this is Momoki from the LINE Developer Day preparation committee.
LINE Developer Day has always been a gathering place for sharing various technological experiences and global challenges and trends, and LINE Developer Day 2016 has just successfully come to a close.
You’ve shown us a great amount of support by registering for the event, so much so that we could only invite a few that were selected from a draw.
We regret that we could only invite about 1000 of you to the event but we thank you all for showing tremendous support all the same!

Applying Kafka Streams for internal message delivery pipeline

Introduction

Hello, my name is Yuto Kawamura. I’m a LINE server engineer in charge of developing and operating LINE’s core storage facilities such as HBase and Kafka.

Since the latter half of last year, I’ve been working on a new project called IMF, which stands for Internal Message Flow (or Fund). IMF has two main goals:

  • Develop a data pipeline which provides a unified way of delivering events between our systems.
  • Replace talk-dispatcher, a component in the LINE server system responsible for background task processing.

The two goals may seem unrelated, but we’re actually trying to adopt the same technologies for both; Apache Kafka and stream processing. Apache Kafka is a high-throughput distributed messaging system that was originally developed and used at LinkedIn. Although Kafka has various unique features, the most important ones are the following:

The next step for even safer messaging: Letter Sealing

In New generation of safe messaging: “Letter Sealing”, we announced that end-to-end encryption (E2EE) has been made available on LINE messages.

But we’ve made even more improvements to safe messaging over the past few months, expanding Letter Sealing to features other than one-on-one chats. We’d like to share some of them here in this post.

Applying CircuitBreaker to Channel Gateway

Before reading

If you have yet to read the introductory article to circuit breakers, I recommend you read the following article first: Circuit Breakers for distributed services

Applying CircuitBreaker to Channel Gateway

Channel Gateway servers provide various LINE server features to content providers. This is why Channel Gateway servers are highly affected by the servers they are connected to, with the effects easily spreading across all Channel Gateway servers.

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