IceGrid is a server activation and location service, as described in Chapter 35. This section describes the ways in which you can integrate Glacier2 and IceGrid.
It is not uncommon for a Glacier2 client to require access to a locator service such as IceGrid. A locator client would typically define the property
Ice.Default.Locator with a stringified proxy for the locator service, as described in
Section 35.4.3. However, when that locator service is accessed via a Glacier2 router, the configuration requirements are slightly different. It is no longer necessary for the client to define
Ice.Default.Locator; this property must be defined in the Glacier2 router’s configuration instead.
An IceGrid application might want to use replication (see Section 35.9) to increase the availability of Glacier2 session managers. When you configure an indirect proxy for a session manager (and configure Glacier2 with a locator proxy, as described in
Section 39.12.1), the Ice run time in the router queries the locator to obtain a proxy for a session manager replica. By default, this proxy is cached for 10 minutes, meaning the router uses the same session manager proxy to create sessions for a 10‑minute period, after which it queries the locator again. If you want to distribute the session-creation load among the session manager replicas more evenly, you can decrease the locator cache timeout using configuration properties. For example, the following settings use a timeout of 30 seconds:
As you can see, timeouts are specified individually for the SessionManager and
SSLSessionManager proxies. You can also disable caching completely by using a value of 0, in which case the router queries the locator before every invocation on a session manager.
See Section 39.6.3 for more information on connection caching.
