Distributed version of the Spring PetClinic Sample Application built with Spring Cloud
December 13, 2017 ยท View on GitHub
This microservices branch was initially derived from AngularJS version to demonstrate how to split sample Spring application into microservices. To achieve that goal we used Spring Cloud Netflix technology stack.
Starting services locally without Docker
Every microservice is a Spring Boot application and can be started locally using IDE or mvn spring-boot:run command. Please note that supporting services (Config and Discovery Server) must be started before any other application (Customers, Vets, Visits and API).
Tracing server and Admin server startup is optional.
If everything goes well, you can access the following services at given location:
- Discovery Server - http://localhost:8761
- Config Server - http://localhost:8888
- AngularJS frontend (API Gateway) - http://localhost:8080
- Customers, Vets and Visits Services - random port, check Eureka Dashboard
- Tracing Server (Zipkin) - http://localhost:9411
- Admin Server (Spring Boot Admin) - http://localhost:9090
You can tell Config Server to use your local Git repository by using local Spring profile and setting
GIT_REPO environment variable, for example:
-Dspring.profiles.active=local -DGIT_REPO=/projects/spring-petclinic-microservices-config
Start script
All services including the inspectIT Java Agent can be started with a start script:
Windows
Open a CMD and execute the script with the directory of the Java Agent:
start_all_with_inspectIT.bat \path\to\Java\Agent.
Additionally you can also set the InspectIT CMR host by passing in a second argument:
start_all_with_inspectIT.bat \path\to\Java\Agent localhost. If no CMR host is provided localhost is used by default.
The services can be stopped by closing the CMD.
Linux
Open a Terminal and execute the script with the directory of the Java Agent:
start_all_with_inspectIT.sh \path\to\Java\Agent.
Additionally you can also set the InspectIT CMR host by passing in a second argument:
start_all_with_inspectIT.sh \path\to\Java\Agent localhost. If no CMR host is provided localhost is used by default.
The services can be stopped by executing the following script:
stop_all.sh
macOS
The macOS users need to first perform following commands (see https://github.com/vishnubob/wait-for-it/issues/15) in order to solve the problem of missing timeout function on their OS:
brew install coreutils
alias timeout=gtimeout
Aside from this, the instructions should be same as for Linux users.
Starting services locally with docker-compose
In order to start entire infrastructure using Docker, you have to build images by executing mvn clean install -PbuildDocker
from a project root. Once images are ready, you can start them with a single command
docker-compose up. Containers startup order is coordinated with wait-for-it.sh script.
After starting services it takes a while for API Gateway to be in sync with service registry,
so don't be scared of initial Zuul timeouts. You can track services availability using Eureka dashboard
available by default at http://localhost:8761.
JMeter load test
A JMX JMeter file for the Petclinic can be found inside the jmeter directory and is called pet_clinic_load_test.jmx. The JMX file can be parameterized with the following parameters and their default values inside the brackets:
JHOST- The host of the system under test (localhost)JPORT- The port of the system under test (8080)JUSERS- The number of users (3)JRAMPUP- The rampup time in seconds (10)JINFLUXDB_HOST- The influx database host (localhost)JLOOPCOUNT- The number of iterations (30)JDURATION- The duration of the test in seconds (100)JDELAY- The delay of the thread creation in seconds (10000)
To start a JMeter load test use the following command:
jmeter -t jmx_file -n -JHOST="localhost" -JPORT="8080" -JUSERS=3
Understanding the Spring Petclinic application with a few diagrams
You can then access petclinic here: http://localhost:8080/
In case you find a bug/suggested improvement for Spring Petclinic Microservices
Our issue tracker is available here: https://github.com/spring-petclinic/spring-petclinic-microservices/issues
Database configuration
In its default configuration, Petclinic uses an in-memory database (HSQLDB) which gets populated at startup with data. A similar setup is provided for MySql in case a persistent database configuration is needed. Note that whenever the database type is changed, the data-access.properties file needs to be updated and the mysql-connector-java artifact from the pom.xml needs to be uncommented.
You may start a MySql database with docker:
docker run -e MYSQL_ROOT_PASSWORD=petclinic -e MYSQL_DATABASE=petclinic -p 3306:3306 mysql:5.7.8
Looking for something in particular?
| Spring Cloud components | Resources |
|---|---|
| Configuration server | Config server properties and Configuration repository |
| Service Discovery | Eureka server and Service discovery client |
| API Gateway | Zuul reverse proxy and Routing configuration |
| Docker Compose | Spring Boot with Docker guide and docker-compose file |
| Circuit Breaker | TBD |
| Graphite Monitoring | TBD |
Contributing
The issue tracker is the preferred channel for bug reports, features requests and submitting pull requests.
For pull requests, editor preferences are available in the editor config for easy use in common text editors. Read more and download plugins at http://editorconfig.org.