2.6 Defining a group hierarchy

Group hierarchy

It is possible to define a group hierarchy with subgroups and servers in a data center. For example:

GroupHierarchyConfig config = new GroupHierarchyConfig()
    .name("Parent Group")
    .subitems(
        group("Group1").subitems(
            group("Group1-1").subitems(
                mysqlServer().count(2),
                apacheHttpServer()
            ),
            group("Group1-2").subitems(
                group("Group1-2-1"),
                nginxServer()
            )
        ),
        group("Group2")
);

In this code, mysqlServer, apacheHttpServer, and nginxServer are instances of the CreateServerConfig class. See example below:

apacheHttpServer = new CreateServerConfig()
    .name("Apache")
    .description(name)
    .type(STANDARD)
    .machine(new Machine()
        .cpuCount(1)
        .ram(2)
        .antiAffinityPolicy(
            AntiAffinityPolicy
                .refByName()
                .name("anti-affinity")
        )
    )
    .template(Template.refByOs()
        .dataCenter(US_CENTRAL_SALT_LAKE_CITY)
        .type(CENTOS)
        .version("6")
        .architecture(x86_64)
    )
    .timeToLive(
        ZonedDateTime.now().plusHours(2)
    );

You can specify a structure with any number of similar servers, for example, mysqlServer().count(2).

The groupService.defineGroupHierarchy call will create the defined hierarchy inside the GroupHierarchyConfig object. First, all the specified groups will be generated. After that, the server creation process will be queued and servers will be created in parallel. This significantly decreases the time necessary for building a hierarchy.

The defineGroupHierarchy call returns the queued operation that will be executed. Here is an example:

OperationFuture<Group> future = groupService.defineGroupHierarchy(DE_FRANKFURT, config);

To ensure that the operation has been completed successfully, call waitUntilComplete():

OperationFuture<Group> finishedFuture = future.waitUntilComplete();

To get the result of a completed operation, call getResult():

Group rootGroupRef = finishedFuture.getResult();

Here, rootGroupRef is the root group of the provided hierarchy ("Parent Group" in the config above).

Super-command functionality

There is also a class similar to GroupHierarchyConfig, but it works for multiple data centers.

OperationFuture<List<Group>> results =
groupService.defineInfrastructure(
    new InfrastructureConfig()
        .dataCenters(DataCenter.DE_FRANKFURT).subitems(
            group("Root Group", "Root Group Description").subitems(
                group("Sub Group").subitems(
                    apacheHttpServer(),
                    mysqlServer()
                ),
                nginxServer(),
                new CreateServerConfig()
                    .name("SRV")
                    .type(null)
                    .machine(new Machine()
                            .cpuCount(1)
                            .ram(2)
                            .antiAffinityPolicy(
                                AntiAffinityPolicy
                                    .refByName()
                                    .name("anti-affinity")
                            )
                    )
            )
        ),
    new InfrastructureConfig()
        .dataCenters(DataCenter.CA_TORONTO_1, DataCenter.US_CENTRAL_SALT_LAKE_CITY)
        .subitems(new GroupHierarchyConfig()
                .name(name("Parent Group"))
                .subitems(
                    group(name("Group1-1")).subitems(
                        group(name("Group1-1-1")).subitems(
                            mysqlServer().count(2)
                        ),
                        group(name("Group1-1-2")).subitems(
                            group(name("Group1-1-2-1")),
                            apacheHttpServer()
                        )
                    ),
                    group(name("Group1-2")
                    )
                )
        )
);

List<Group> rootGroupRefs = results.waitUntilComplete().getResult();

rootGroupRefs is the list of root groups in each data center defined in the config above.