Read documents of Apache shardingsphere several years ago, and used to think it is the best database sharding library in client side. After trying to use it in a real-world application, problems reveal. First, the ecosystem has grown so large. Even a demo spring boot application can reference lots of dependencies. Second, when loading large data set from multiple shards, multi-threading is not used. I still have to manually implement it myself to improve load time.

Actually, what I need is the ability for selecting a database shard implicitly. When I write select t_user from..., it is rewritten to select t_user[0-7] from.... Here’s some alternative options I found:

1. hibernate interceptor

Refer to javadoc of StatementInspector class.

2. datasource proxy

See: https://jdbc-observations.github.io/datasource-proxy/docs/current/user-guide/#built-in-support

3. spring boot 3

See: https://spring.io/blog/2022/05/02/ever-wanted-to-rewrite-a-query-in-spring-data-jpa

But spring boot 3 requires java 17 and it only applies to jpa repository.

https://github.com/gonwan/toys/blob/master/webframework-benchmark/readme.md

See Techempower. This repository contains homemade java benchmarks using spring-mvc, spring-webflux and netty-http/netty-tcp servers based on reactor-netty. gin and gnet are also included. wrk is used as client. gobench is also considered but it is not so good as wrk.

Environment 1

  • Server: 8C16G vm
  • Client: 4C8G vm * 2
Server Server Throughput Server CPU
spring-mvc 25k ~ 30k /s ~600%
spring-webflux 90k ~ 110k /s ~780%
go-gin 110k ~ 120k /s ~600%
go-gnet 110k ~ 120k /s ~270%
netty-http 110k ~ 120k /s ~480%
netty-tcp 110k ~ 120k /s ~360%

2 VM Clients are not able to fully utilize the server capability. The initial attempts were benchmarking only first 4 cases. And the go-gnet results made me wonder, it can give much more throughput. After reading the source of it, I found go-gnet case is actually a TCP server with very very little of HTTP implementation to fulfill the benchmark, which is unfair for other cases. Therefore, I added case 5/6 in java to align with it.

Environment 2

  • Server: 24C32G physical machine
  • Client:
    • 4C8G vm * 2
    • 8C16G vm * 1
    • 24C32G physical machine * 1
Server Server Throughput Server CPU
spring-mvc ~120k /s ~1560%
spring-webflux ~180k /s ~2380%
go-gin ~380k /s ~2350%
go-gnet 560k ~ 580k /s ~1160%
netty-http 560k ~ 580k /s ~2350%
netty-tcp 560k ~ 580k /s ~1460%

Still room to give more throughput in go-gnet and netty-tcp cases. Not having so many idle systems for benchmarking now. The throughput should have a linear increment when more CPU is utilized, in both cases.

As a developer, spring-mvc or go-gin can still be the first choice, as they are easier to get started.

 

Recently played with the Spring/SpringBoot/SpringCloud stack with a toy project: https://github.com/gonwan/spring-cloud-demo. Just paste README.md here, and any pull request is welcome:

Introduction

The demo project is initialized from https://github.com/carnellj/spmia-chapter10. Additions are:

  • Code cleanup, bug fix, and better comments.
  • Java 9+ support.
  • Spring Boot 2.0 migration.
  • Switch from Postgres to MySQL, and from Kafka to RabbitMQ.
  • Easier local debugging by switching off service discovery and remote config file lookup.
  • Kubernetes support.
  • Swagger Integration.
  • Spring Boot Admin Integration.

The project includes:

  • [eureka-server]: Service for service discovery. Registered services are shown on its web frontend, running at 8761 port.
  • [config-server]: Service for config file management. Config files can be accessed via: http://${config-server}:8888/${appname}/${profile}. Where ${appname} is spring.application.name and ${profile} is something like dev, prd or default.
  • [zipkin-server]: Service to aggregate distributed tracing data, working with spring-cloud-sleuth. It runs at 9411 port. All cross service requests, message bus delivery are traced by default.
  • [zuul-server]: Gateway service to route requests, running at 5555 port.
  • [authentication-service]: OAuth2 enabled authentication service running at 8901. Redis is used for token cache. JWT support is also included. Spring Cloud Security 2.0 saves a lot when building this kind of services.
  • [organization-service]: Application service holding organization information, running at 8085. It also acts as an OAuth2 client to authentication-service for authorization.
  • [license-service]: Application service holding license information, running at 8080. It also acts as an OAuth2 client to authentication-service for authorization.
  • [config]: Config files hosted to be accessed by config-server.
  • [docker]: Docker compose support.
  • [kubernetes]: Kubernetes support.

NOTE: The new OAuth2 support in Spring is actively being developed. All functions are merging into core Spring Security 5. As a result, current implementation is suppose to change. See:

Tested Dependencies

  • Java 8+
  • Docker 1.13+
  • Kubernetes 1.11+

Building Docker Images

In case of running out of disk space, clean up unused images and volumes with:

Running Docker Compose

Or with separate services:

Running Kubernetes

NOTE: Kubernetes does not support environment variable substitution by default.

Use Cases

Suppose you are using the kubernetes deployment.

Get OAuth2 token

curl is used here, and 31004 is the cluster-wide port of the Zuul gateway server:

Get organization info

Use the token returned from previous request.

Get license info associated with organization info

Use the token returned from previous request.

Distributed Tracing via Zipkin

Every response contains a correlation ID to help diagnose possible failures among service call. Run with curl -v to get it:

Search it in Zipkin to get all trace info, including latencies if you are interested in.
zipkin-1
zipkin-2

The license service caches organization info in Redis, prefixed with organizations:. So you may want to clear them to get a complete tracing of cross service invoke.

Working with OAuth2

All OAuth2 tokens are cached in Redis, prefixed with oauth2:. There is also JWT token support. Comment/Uncomment @Configuration in AuthorizationServerConfiguration and JwtAuthorizationServerConfiguration classes to switch it on/off.

Swagger Integration

The organization service and license service have Swagger integration. Access via /swagger-ui.html.

Spring Boot Admin Integration

Spring Boot Admin is integrated into the eureka server. Access via: http://${eureka-server}:8761/admin.
sba-1