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Distributed Architecture Guide

Use the Atoti Starter​

In a Spring application, the different components used in distribution like the messenger will be automatically created by Atoti starter for Spring Boot com.activeviam.springboot:atoti-server-starter. Import this dependency in your project to perform this injection.
In the context of tests, Atoti comes with the class com.activeviam.atoti.server.test.api.DistributionTestHelper handling this setup. See the specific section for details about its setup and usage.

Configure your application​

The first step to define an application is to define a database. This is done like in a non-distributed application (see Database Overview)

The second step is to define the data nodes and the query nodes. Here as an example of a data node definition: 

final IActivePivotInstanceDescription datanode =
    StartBuilding.cube("datanode")
        .withSingleLevelDimension("trade")
        // define here the measures and the hierarchies of the data node
        .asDataCube()
        .withClusterDefinition()
        .withClusterId("Cluster")
        .withMessengerDefinition()
        .withProtocolPath("jgroups-protocols/protocol-tcp.xml")
        .end()
        .withApplicationId("app")
        .withConcealedHierarchies(List.of(HierarchyIdentifier.simple("trade")))
        .withConcealedMeasures("Value.SUM")
        .withConcealedBranches()
        .end()
        .build();
The cluster can define its messenger with a protocol path or simply call the withLocalMessenger or the withNettyMessenger methods. This is the moment to conceal the hierarchies, the measures or the branches if it applies here (see Recommendations)

And of a query node definition: 

final IDistributedActivePivotInstanceDescription queryNode =
    StartBuilding.cube("querynode")
        .asQueryCube()
        .withClusterDefinition()
        .withClusterId("Cluster")
        .withMessengerDefinition()
        .withProtocolPath("jgroups-protocols/protocol-tcp.xml")
        .end()
        .withApplication("app")
        .withDistributingLevels(LevelIdentifier.simple("trader"))
        .withApplication("app2")
        .withoutDistributingLevels()
        .end()
        .build();
The query node will see all the data nodes belonging to the applications listed in its configurations.

Once the nodes have been defined, they should be added to a manager: 

final IActivePivotManagerDescription manager =
    StartBuilding.managerDescription("MyManager")
        .withCatalog("Catalog")
        .containingAllCubes()
        .withSchema("Schema")
        .withSelection(createSelection())
        .withCube(datanode)
        .withDistributedCube(queryNode)
        .build();
The last step is to put the database and the manager together in an application: 
final ApplicationWithDatastore application =
    StartBuilding.application()
        .withDatastore(createDatastoreSchemaDescription())
        .withManager(manager)
        .build();

Leave a cluster​

It is possible to join and leave the cluster programmatically like this: 

// Join the cluster
((IMultiVersionDataActivePivot) multiVersionActivePivot).startDistribution();
// Leave the cluster
((IMultiVersionDataActivePivot) multiVersionActivePivot).stopDistribution();

If a data node leaves the cluster before sending all the expected query results to a query node, a ServiceUnavailableException is thrown.