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.
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The Slice definitions shown below comprise the IceBox administrative interface:
{zcode:slice} module IceBox { exception AlreadyStartedException {}; exception AlreadyStoppedException {}; exception NoSuchServiceException {}; interface ServiceObserver { void servicesStarted(Ice::StringSeq services); void servicesStopped(Ice::StringSeq services); }; interface ServiceManager { idempotent Ice::SliceChecksumDict getSliceChecksums(); void startService(string service) throws AlreadyStartedException, NoSuchServiceException; void stopService(string service) throws AlreadyStoppedException, NoSuchServiceException; void addObserver(ServiceObserver* observer) void shutdown(); }; }; {zcode} |
ServiceManager
InterfaceThe ServiceManager
interface provides access to the service manager object of an IceBox server. It defines the following operations:
getSliceChecksums
startService
NoSuchServiceException
. If the service is already active, the operation raises AlreadyStartedException
.stopService
NoSuchServiceException
if no matching service is found, and AlreadyStoppedException
if the service is stopped at the time stopService
is invoked.addObserver
shutdown
ServiceObserver
InterfaceAn 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:
servicesStarted
servicesStopped
The IceBox server unregisters an observer if the invocation of either operation causes an exception.
Our discussion of IceGrid includes an example that demonstrates how to register a ServiceObserver
callback with an IceBox server deployed with IceGrid.
IceBox's administrative functionality is disabled by default. You can enable it in two ways:
IceBox.ServiceManager
object adapter.For example, the following configuration property enables the IceBox.ServiceManager
object adapter:
{zcode} IceBox.ServiceManager.Endpoints=tcp -h 127.0.0.1 -p 10000 {zcode} |
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.
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.
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.
IceBox.ServiceManager
Object AdapterWhen 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:
{zcode} IceBox.InstanceName=IceBox1 {zcode} |
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
. 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:
{zcode} Ice.Admin.Endpoints=tcp -h 127.0.0.1 -p 10001 Ice.Admin.InstanceName=IceBox {zcode} |
In this case, the identity of the admin
object is IceBox/admin
.
IceBox also registers a Properties
facet for each of its services so that the configuration properties of a service can be inspected remotely. The facet name is constructed as follows:
{zcode} IceBox.Service.name.Properties {zcode} |
The value name
represents the service name.
A client requiring administrative access to the service manager can create a proxy using the endpoints configured for the service manager.
IceBox.ServiceManager
Object AdapterTo 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.
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. 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 our discussion of IceGrid 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:
{zcode} Ice.Admin.InstanceName=IceBox {zcode} |
A client can define the proxy for the admin
object in a configuration property as follows:
{zcode} ServiceManager.Proxy=IceBox/admin -f IceBox.ServiceManager -h 127.0.0.1 -p 10001 {zcode} |
The proxy option -f IceBox.ServiceManager
specifies the name of the service manager's administrative facet.
IceBox includes C++ and Java implementations of an administrative utility. The utilities have the same usage:
{zcode} 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. {zcode} |
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, which provide equivalent commands for administering an IceBox server. Otherwise, the proxy should have the endpoints and identity configured for the server.