Breakerbox

Breakerbox is a dashboard and dynamic configuration tool for Tenacity.

Running Breakerbox

Required: Breakerbox requires you to instrument your code with Tenacity which is a library to aid in resilient design of foreign dependencies.

Download a release or build it yourself with maven

Extract the archive and then run the following command

java -Darchaius.configurationSource.additionalUrls=file:config.properties -jar breakerbox-service-0.1.0.jar server breakerbox.yml

Then point your browser at http://localhost:8080. You should see a dashboard consisting of the local Breakerbox instance. By default it's backed by an in memory database, so any configuration changes you'll make won't be persisted anywhere until your configure it.

Configuring Breakerbox

Here's a very simple bare configuration of Breakerbox. Each section will be described in detail.

breakerbox:
  urls: file:config.properties,http://localhost:8080/archaius/breakerbox
  initialDelay: 5s
  delay: 60s

database:
  driverClass: org.h2.Driver
  url: jdbc:h2:mem:inMemory
  user: breakerbox
  password: breakerboxpass
  maxSize: 10
  minSize: 2
  checkConnectionWhileIdle: true
  checkConnectionHealthWhenIdleFor: 1s

tenacityClient:
  connectionTimeout: 500ms
  timeout: 1000ms

server:
  applicationConnectors:
    - type: http
      port: 8080
  adminConnectors:
    - type: http
      port: 8081
  gzip:
    enabled: false
  requestLog:
    appenders:
      - type: file
        currentLogFilename: /var/log/breakerbox/requests.log
        archivedLogFilenamePattern: /var/log/breakerbox/requests-%d.log
        archivedFileCount: 5

logging:
  level: INFO
  appenders:
    - type: file
      currentLogFilename: /var/log/breakerbox/breakerbox.log
      archivedLogFilenamePattern: /var/log/breakerbox/breakerbox-%d.log
      archivedFileCount: 5

Gzip Disabled

Javascript's EventSource doesn't support gzip encoded streams.

Persistence Storage

You can choose between using an in-memory database, Postgresql (potentially other RDBMSes, I've just only tested with Postgresql for now), and Azure Table.

For Postgresql simply modify the database section to (assumes the database "breakerbox" is created):

database:
  driverClass: org.postgresql.Driver
  url: jdbc:postgresql://localhost/breakerbox

If you wish to use Azure Table remove the database section entirely and add

azure:
  accountName: your_test_account
  accountKey: security_key
  timeout: 2s
  retryInterval: 500ms
  retryAttempts: 1

If you specify both database and azure it will only leverage the database store.

Authentication

By default users that save configuration's will save it under the name anonymous.

At the moment it only supports authenticating users via LDAP and HTTP Basic-Auth which is configurable by adding:

ldap:
  uri: ldaps://ldap.com
  cachePolicy: maximumSize = 10000, expireAfterAccess = 15m
  userFilter: ou=users,dc=company,dc=com
  userNameAttribute: cn
  connectTimeout: 500ms
  readTimeout: 500ms

If you need group membership filters you can see the additional documentation on dropwizard-auth-ldap

Dashboard Configuration

The config.properties file uses Turbine's configuration syntax. This currently assumes a static setup. It isn't hard to add a dynamic host discovery system, but this is something that will be added on later.

turbine.aggregator.clusterConfig: specifies all the dashboards you'd like to create. (e.g. production, serviceA, serviceB)
turbine.instanceUrlSuffix=/tenacity/metrics.stream: use this default because this is where tenacity puts the metrics streaming endpoint.
turbine.ConfigPropertyBasedDiscovery.production.instances: this specifies the individual instances that make up the production cluster.
turbine.ConfigPropertyBasedDiscovery.breakerbox.instances: this specifies the individual instances that make up the breakerbox cluster.

turbine.aggregator.clusterConfig=production,breakerbox
turbine.instanceUrlSuffix=/tenacity/metrics.stream
turbine.ConfigPropertyBasedDiscovery.production.instances=localhost:8080,anotherservice.company.com:8080
turbine.ConfigPropertyBasedDiscovery.breakerbox.instances=localhost:8080

Note: Easiest thing to do is make sure config.properties is in the same directory as the jar otherwise keep the breakerbox#urls and the archaius.configurationSource.additionalUrls system property pointing to the correct location. We plan to move this to a better configuration mechanism in the future.

Adding Breakerbox to your Dropwizard+Tenacity Service

In any Tenacity service to have it poll Breakerbox for dynamic configurations add this to your service configuration.

urls: A comma-delimited list of breakerbox instances. The cluster you added in the config.properties is the identifier you want to supply here.
initialDelay: How long it should wait before the first poll.
delay: The interval at which to constantly check Breakerbox for configuration items. Here we specify every minute we'd like to check for new configurations.

breakerbox:
  urls: http://breakerbox:8080/archaius/{the-cluster-you-setup-in-breakerbox}
  initialDelay: 0s
  delay: 60s

There is a configuration hierarchy priority and it's good to understand it especially when using dynamic configurations.

Breakerbox
Service configuration YAML
Tenacity defaults

Additional Configuration

Here's a collection of things we have found very useful to make configurable.

hystrixMetricsStreamServletMaxConnections: The max number of connections any Dropwizard+Tenacity service will allow from Breakerbox.
turbineHostRetry: The interval at which to reconnect to a failed instance. 1s may be a bit fast as a default :)

archaiusOverride:
  turbineHostRetry: 1s
  hystrixMetricsStreamServletMaxConnections: 5

The client Breakerbox uses to fetch latest property keys and configurations is configurable by

tenacityClient:
  connectionTimeout: 500ms
  timeout: 1000ms

Building Breakerbox

mvn clean package

The artifact will then be available under breakerbox-service/target.

Running Tests

mvn test

breakerbox-azure doesn't have a mock for Azure Table as it wouldn't be that useful, so it requires a valid Azure Table account to run the tests. If you do not supply a valid Azure Table account, these tests will be ignored.

Docker

Justin Plock created a Docker for Breakerbox

praveenag/breakerbox