MyLifeForCoding | Joohyun Ha Blog.

Hi, I'm Joohyun Ha. I do stuffs with computer and sometimes write about it here. I'm from Seoul, Korea.

2025

Aug 24

API Rate Limiting

Aug 13

OAuth 2.0 Token Introspection

Jun 24

Handling Split Logs with Fluent Bit on ECS

Jun 23

How to Increase Datadog Log Index Retention Period

Mar 07

Urchin Tracking Module (UTM)

Feb 23

Fixing Hibernate Memory Pagination

Feb 22

Accessing Original Class Annotations in Spring Proxy Objects

Jan 11

2024

Dec 31

Database Sharding

Nov 24

Feature Toggle (aka Feature Flag)

Nov 23

Handling Database Schema Changes in Canary Deployments

Nov 21

Fluent Bit, AWS FireLens

Nov 20

Datadog Integration with AWS ECS Fargate using Terraform

Nov 15

@OneToOne N+1 Solution

Nov 13

Firebase Cloud Messaging (FCM) Docs

Nov 04

Configuring Multiple Firebase Beans in Spring Boot

Nov 02

Useful Websites Link Collection

Oct 30

Cross-Account S3 Bucket Data Migration Guide

Oct 29

AWS Free Tier: Only One Account per Organization

Oct 28

Throttle vs Debounce

Oct 25

Using Route 53 to Link Subdomains with Separate Name Servers

Oct 16

Vehicle Domain Dictionary

Oct 15

How to Resolve CloudFront CNAME Conflict

Oct 06

Oct 02

Load Testing Using K6

Sep 29

Deploying Custom CLI Commands with Homebrew

Sep 27

How to Apply ECS Capacity Provider in AWS CodeDeploy

Sep 16

Sep 14

Infrastructure as Code: Principles, Pattenrns

Aug 19

TimeLimiter 'name' recorded a timeout exception. - Resilience4j

Aug 15

Slack Client in Spring Boot

Aug 14

AWS Policy AWSCompromisedKeyQuarantineV2

Aug 07

Kotlin JSON Field Masking with Jackson

Aug 04

Telegram Messaging in Spring

Aug 02

Logging JSON in Spring Boot with StructuredArguments

Jul 31

Avoiding Circular Dependencies in Spring Boot with Feign and Interceptors

Jul 30

Preflight Request

Jul 14

HTTP POST for Search

Jul 11

Guide to Integrating NICE Mobile Authentication API

Jul 11

Address Geocoding

Jul 08

How to Obtain Administrative Polygon Data in South Korea

Jul 07

Trunk Based Development (TBD)

Jun 23

MultipleBagFetchException

Jun 17

Http Methods (POST, PUT, PATCH)

Jun 08

Git Stash Commits

Jun 07

May 27

Server Sent Events (SSE)

May 24

Idempotency Key

May 19

May 18

Cosine Similarity

May 16

TransactionalEventListener

May 14

May 13

Various Ways to Create an ID

May 09

May 08

Backend for Frontend in Microservices (BFF)

Apr 29

EnvironmentPostProcessor

Apr 28

Spring Boot Multi Module with Kotlin

Apr 27

Difference between implementation, api in Gradle Dependency

Apr 22

Apr 21

Consistent Hashing

Apr 19

Apr 16

When allowCredentials is true, allowedOrigins cannot contain the special value "*"

Apr 15

Logging Request & Response in Spring Boot

Apr 05

Design Pattern - Strategy Pattern

Apr 04

Firestore Transaction and Batched Write

Apr 03

Mar 23

The new features in Java 21

Mar 19

How to select Runner in Gitlab?

Mar 16

How to use nginx X-Forwarded-For Header?

Mar 08

Circuit Breaker Pattern

Mar 04

How to find JVM flag?

Feb 27

JVM Memory: MetaSpace

Feb 26

Terraform Tutorials

Feb 15

Feb 13

New AWS Public IPv4 Address Chrage, Public IP Insights

Feb 07

Percentile - P90, P95

Feb 06

Jan 30

Set MDC(TraceId) in Webflux

Jan 29

AWS CloudWatch in Spring Boot

Jan 25

Error: commit {hash} is a merge but no -m option was given.

Jan 15

Git Revert Command

Jan 05

JPA itself does not support nested transactions

2023

Dec 11

EXPLAIN Statement

Dec 09

Register Gitlab Runner

Dec 07

Escape character

Dec 06

Dec 03

Nov 24

Effective UUID storage way from Mysql

Oct 10

GOPATH vs go.mod

Sep 28

Aug 28

Sliding Session

Aug 16

Handling AOP using Trailing Lambdas in Kotlin

Aug 06

Self-invocation does not work for proxies in Spring AOP

Aug 02

Git Stash Command

Jul 31

Multipart Properties

Jun 27

Why does a memory leak occur from an inner class in Java?

2022

Aug 21

Frequently used IntelliJ shortcuts

Jul 22

Jul 12

Mar 09

Using Querydsl on billions of requests - woowacon2020

Mar 01

Increase insert performance with batch insert

Feb 24

How to handle null in koltin - ? ?. ?: !! as?

Feb 18

Practice tdd, refactor - woowahan tech seminar

Jan 27

Remove git commit message using rebase command

Jan 22

Is it possible to chage the value of primary and foreign keys?

2021

Dec 30

Transaction Isolation Level

Dec 28

Dec 27

Cache Memory and Locality

Dec 26

Sqrt Decomposition Algorithm

Dec 08

Spring Interceptor

Dec 04

Programmer SQL high score kit correct answer

Dec 03

Dec 02

Sep 15

Spring Annotation - @Cacheable, @CachePut, @CacheEvict

Sep 06

Hibernate Annotation - @DynamicInsert, @DynamicUpdate

Sep 04

Types of Git Merge

Aug 04

Learn about Zero-downtime deployment and Implement blue-green deployment with nginx

Aug 02

Implement CI&CD with Jenkins and Github

Jul 29

Apply to Https to Nginx

Jul 28

Web Server Nginx

Jul 18

Implement KAKAO login using REST API

Jul 16

Label object with python

Jun 07

Extract colors with morphology expansion operation and InRange() function with python

May 21

Extract colors into the image with python

May 13

How to update configuration with bus?

May 12

Implement Spring Cloud Config

Apr 19

Frequently used git commands

Apr 18

Implement filter and load balancer using gateway

Apr 10

Spring Cloud Netflix Zuul

Apr 08

Spring Cloud API Gateway Service

Apr 07

Spring Cloud Service Discovery

Apr 06

Spring Cloud Netflix Eureka

Feb 22

Java Virtual Machine(JVM)

Feb 21

Microservices vs Monolithic Architecture

Feb 20

The Flow of Spring MVC Framework

Feb 19

The Flow of the HTTP

Feb 17

Hypertext Transfer Protocol(HTTP)

Feb 06

JPA Persistence Context

Jan 31

JPA N + 1 query

Jan 27

How to set multi-to-one two-way relationship owner?

Jan 25

What is ModelMapper, MapStruct?"