Using IceRPC with an Ice application

Interop basics

IceRPC provides interop with Ice by implementing the ice protocol over the tcp/ssl duplex transport (with some limitations), and by supporting the Ice encoding and the Slice language.

In practice, this means you can write a new IceRPC client for an existing Ice server, reimplement an existing Ice server using IceRPC, or use IceRPC to create new services for your Ice clients.

If you start from an existing Ice client or server, the first step is to convert your Slice definitions (in .ice files) to the new Slice syntax. The converted Slice files must specify Slice1 mode:

mode = Slice1 // required for interop with Ice
...

Make sure to use the .slice extension for these new Slice files.

If you use IceRPC to create new services for your Ice client, you should start by defining your Slice interfaces with the new Slice syntax (and mode = Slice1) before converting these definitions to the .ice Slice syntax. The new syntax allows you to mark a class parameter/field as optional or non-optional, for example:

interface ContactRegistry {
    // The new contact cannot be null / not-set.
    addContact(contact: Contact)

    // Returns null/not-set when not found.
    findContact(name: string) -> Contact?
}

class Contact {
    name: string
    ...
}

With the .ice Slice syntax, you can't make this distinction: a class parameter/field is always optional.

Limitations

The main interop limitation for clients is IceRPC does not currently provide support for calling a server behind a Glacier2 router. So if you have an Ice client that calls a server through Glacier2, you cannot reimplement this client with IceRPC.

This is a temporary limitation, not a fundamental design choice within IceRPC.

The main interop limitations for servers is batch requests and IceGrid support.

If your Ice clients send batches requests, you can't reimplement the corresponding Ice server with IceRPC since IceRPC does not accept batch requests.

If your Ice server is managed (especially started) by IceGrid, you can't reimplement this server with IceRPC. IceGrid generates Ice configuration files for the Ice servers it starts and IceRPC provides no support for Ice configuration files.