An IceBox server internally creates an object called the service manager that is responsible for loading and initializing the configured services. You can optionally expose this object to remote clients, such as the IceBox and IceGrid administrative utilities, so that they can execute certain administrative tasks.
module IceBox {
exception AlreadyStartedException {};
exception AlreadyStoppedException {};
exception NoSuchServiceException {};
interface ServiceObserver {
["ami"] void servicesStarted(Ice::StringSeq services);
["ami"] void servicesStopped(Ice::StringSeq services);
};
interface ServiceManager {
idempotent Ice::SliceChecksumDict getSliceChecksums();
["ami"] void startService(string service)
throws AlreadyStartedException, NoSuchServiceException;
["ami"] void stopService(string service)
throws AlreadyStoppedException, NoSuchServiceException;
["ami"] void addObserver(ServiceObserver* observer)
void shutdown();
};
};
The ServiceManager interface provides access to the service manager object of an IceBox server. It defines the following operations:
Starts a pre-configured service that is currently inactive. This operation cannot be used to add new services at run time, nor will it cause an inactive service’s implementation to be reloaded. If no matching service is found, the operation raises
NoSuchServiceException. If the service is already active, the operation raises
AlreadyStartedException.
An administrative client that is interested in receiving callbacks when IceBox services are started or stopped must implement the
ServiceObserver interface and register the callback object’s proxy with the service manager using its
addObserver operation. The
ServiceObserver interface defines two operations:
Section 35.21.3 demonstrates how to register a
ServiceObserver callback with an IceBox server deployed with IceGrid.
Similarly, the Ice administrative facility requires that endpoints be defined for the Ice.Admin object adapter with the property
Ice.Admin.Endpoints. Note that the
Ice.Admin object adapter is enabled automatically in an IceBox server that is deployed by IceGrid (see
Section 35.21).
Regardless of which object adapter(s) you choose to enable, exposing the service manager makes an IceBox server vulnerable to denial-of-service attacks from malicious clients. Consequently, you should choose the endpoints and transports carefully;
Section 28.18.8 explores these issues in greater depth.
Although an IceBox server has only one service manager object, the object is accessible via two different identities depending on how the administrative functionality was enabled (see
Section 40.5.2).
The IceBox.ServiceManager Object Adapter
When this object adapter is enabled, the service manager object has the default identity
IceBox/ServiceManager. If an application requires the use of multiple IceBox servers, it is a good idea to assign unique identities to their service manager objects by configuring the servers with different values for the
IceBox.InstanceName property, as shown in the following example:
This property changes the category of the object’s identity, which becomes IceBox1/ServiceManager. A corresponding change must be made in the configuration of administrative clients.
When this facility is enabled, the service manager is added as a facet of the server’s
admin object. As a result, the identity of the service manager is the same as that of the
admin object, and the name of its facet is
IceBox.ServiceManager.
Section 28.18.1 explains that the identity of the
admin object uses either a UUID or a statically-configured value for its category, and the value
admin for its name. For example, consider the following property definitions:
IceBox also registers a Properties facet (see
Section 28.18.5) for each of its services so that the configuration properties of a service can be inspected remotely. The facet name is constructed as follows:
The value name represents the service name.
Using the IceBox.ServiceManager Object Adapter
To access the service manager via the IceBox.ServiceManager object adapter, the proxy should use the default identity
IceBox/ServiceManager unless the server has changed the category using the
IceBox.InstanceName property (see
Section 40.5.3).
To access the service manager via the administrative facility, the client must first obtain (or be able to construct) a proxy for the
admin object. As explained in
Section 28.18.1, the default identity of the
admin object uses a UUID for its category, which means the client cannot predict the identity and therefore will be unable to construct the proxy itself. If the IceBox server is deployed with IceGrid, the client can use the technique described in
Section 35.21.3 to access its
admin object.
In the absence of IceGrid, the IceBox server should set the Ice.Admin.InstanceName property if remote administration is required. In so doing, the identity of the
admin object becomes well-known, and a client can construct the proxy on its own. For example, let us assume that the IceBox server defines the following property:
A client can define the proxy for the admin object in a configuration property as follows:
The proxy option -f IceBox.ServiceManager specifies the name of the service manager’s administrative facet.
Usage: iceboxadmin [options] [command...]
Options:
‑h, ‑‑help Show this message.
‑v, ‑‑version Display the Ice version.
Commands:
start SERVICE Start a service.
stop SERVICE Stop a service.
shutdown Shutdown the server.
The C++ utility is named iceboxadmin, while the Java utility is represented by the class
IceBox.Admin.
The start command is equivalent to invoking
startService on the service manager interface. Its purpose is to start a pre-configured service; it cannot be used to add new services at run time. Note that this command does not cause the service’s implementation to be reloaded.
Similarly, the stop command stops the requested service but does not cause the IceBox server to unload the service’s implementation.
The shutdown command stops all active services and shuts down the IceBox server.
The C++ and Java utilities obtain the service manager’s proxy from the property
IceBoxAdmin.ServiceManager.Proxy, therefore this proxy must be defined in the program’s configuration file or on the command line, and the proxy’s contents of depend on the server’s configuration. If the IceBox server is deployed with IceGrid, we recommend using the IceGrid administrative utilities instead (see
Section 35.23), which provide equivalent commands for administering an IceBox server. Otherwise, the proxy should have the endpoints configured for the server as described in
Section 40.5.2 and the identity as described in
Section 40.5.3.
