Application Continuum

The evolution of a component-based architecture

See Git tags for step-by-step notes.

git tag -ln
v1 First commit
v2 Functional groups
v3 Feature groups (Bounded Context)
v4 Components
v5 Applications
v6 Services
v7 Databases
v8 Versioning
v9 Service Discovery
v10 Circuit Breaker

Getting started

1. Install redis

   brew install redis

2. Modify /opt/homebrew/etc/redis.conf (/usr/local/etc/redis.conf on Intel Macs)

   requirepass foobared

3. Install mysql

   brew install mysql

4. Modify /opt/homebrew/etc/my.cnf (/usr/local/etc/my.cnf on Intel Macs)

   default-time-zone='+00:00'
   

5. Database setup

   mysql -v -uroot --execute="drop user 'uservices'@'localhost'"
   mysql -v -uroot --execute="create user 'uservices'@'localhost' identified by 'uservices';"fordatabase_namein'allocations''backlog''registration''timesheets';do
   mysql -v -uroot --execute="drop database if exists ${database_name}_test"
   mysql -v -uroot --execute="create database ${database_name}_test"
   mysql -v -uroot --execute="grant all on ${database_name}_test.* to 'uservices'@'localhost';"
   mysql -v -uroot --execute="grant select on performance_schema.* to 'uservices'@'localhost';"done
   mysql -v -uuservices -puservices registration_test --execute="select now();"

6. Schema Migrations

   flyway -reportEnabled=false -cleanDisabled=false -user=uservices -password=uservices -url="jdbc:mysql://localhost:3306/allocations_test" -locations=filesystem:databases/allocations-database clean migrate
   flyway -reportEnabled=false -cleanDisabled=false -user=uservices -password=uservices -url="jdbc:mysql://localhost:3306/backlog_test" -locations=filesystem:databases/backlog-database clean migrate
   flyway -reportEnabled=false -cleanDisabled=false -user=uservices -password=uservices -url="jdbc:mysql://localhost:3306/registration_test" -locations=filesystem:databases/registration-database clean migrate
   flyway -reportEnabled=false -cleanDisabled=false -user=uservices -password=uservices -url="jdbc:mysql://localhost:3306/timesheets_test" -locations=filesystem:databases/timesheets-database clean migrate

7. Run tests

   ./gradlew build

Running the servers

Each server is configured through environment variables. Build the runnable jars first:

./gradlew build

Start the discovery server (backed by redis):

PORT=8888 \
REDIS_HOST=localhost \
REDIS_PASSWORD=foobared \
java -jar applications/discovery-server/build/libs/discovery-server.jar

Then start each application server (backed by mysql), pointing it at the discovery server:

PORT=8881 \
DATABASE_URL="jdbc:mysql://localhost:3306/allocations_test?user=uservices&password=uservices" \
DISCOVERY_SERVER_ENDPOINT=http://localhost:8888 \
java -jar applications/allocations-server/build/libs/allocations-server.jar
PORT=8882 \
DATABASE_URL="jdbc:mysql://localhost:3306/backlog_test?user=uservices&password=uservices" \
DISCOVERY_SERVER_ENDPOINT=http://localhost:8888 \
java -jar applications/backlog-server/build/libs/backlog-server.jar
PORT=8883 \
DATABASE_URL="jdbc:mysql://localhost:3306/registration_test?user=uservices&password=uservices" \
DISCOVERY_SERVER_ENDPOINT=http://localhost:8888 \
java -jar applications/registration-server/build/libs/registration-server.jar
PORT=8884 \
DATABASE_URL="jdbc:mysql://localhost:3306/timesheets_test?user=uservices&password=uservices" \
DISCOVERY_SERVER_ENDPOINT=http://localhost:8888 \
java -jar applications/timesheets-server/build/libs/timesheets-server.jar

Variable	Used by	Description
PORT	all servers	Port the server listens on
DATABASE_URL	application servers	JDBC URL for the server's mysql database
REDIS_HOST / REDIS_PASSWORD	discovery server	Redis connection used for the service registry
DISCOVERY_SERVER_ENDPOINT	application servers	Base URL of the discovery server for heartbeats and lookups