Specifying How Your Domains Connect

You can specify the conditions under which a local domain gateway tries to establish a connection to a remote domain by selecting one of the following connection policies:

Determining the Availability of Remote Services with the Dynamic Status Feature

The gateway process (GWTDOMAIN) advertises those services that are imported from one or more remote domains in the bulletin board. These services typically remain advertised regardless of whether the remote service is reachable.

The capability of the BEA Tuxedo domain gateways known as Dynamic Status reports the status (as determined by the BEA Tuxedo system) of remote services.

When Dynamic Status is in effect, the status of a remote service depends on the status of the network connection between the local and remote gateways. Remote services are considered available whenever a connection to the domain on which they reside is available. When a network connection to a remote domain is not available, services in that domain are considered unavailable. This policy is invoked when the connection policy is ON_STARTUP (that is, when a local domain gateway tries to establish a connection to a remote domain at boot time) or INCOMING_ONLY (that is, when a local domain gateway does not try to establish a connection to remote domains upon starting).

For each service, the gateway keeps track, not only of the remote domains from which the service is imported, but also of which remote domains are available. In this way, the gateway provides intelligent load balancing of requests to remote domains. If all the remote domains from which a service is imported become unreachable, the service is suspended in the bulletin board.

For example, suppose a service called RSVC is imported from two remote domains, as specified by the following entries in the DM_REMOTE_SERVICES section of the configuration file:

RSVC RDOM=R1
RSVC RDOM=R2

When connections to both R1 and R2 are up, the gateway load balances requests for the RSVC service. If the connection to R1 goes down, the gateway sends all requests for RSVC to R2. If both connections go down, the gateway suspends RSVC in the bulletin board. Subsequent requests for RSVC are either routed to a local service or another gateway, or fail with TPENOENT.

Note: When the connection policy is ON_DEMAND, a connection is attempted only when either a client requests a remote service or an administrative "connect" command is run.

How Your Connection Policy Affects Dynamic Status

Dynamic Status is not available in all Domains configurations; whether it is available depends on which connection policy you establish between your domains. The following table describes how each connection policy affects Dynamic Status.

Availability of Dynamic Status