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DbEnv::set_rep_transport
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#include <db_cxx.h>
int
DbEnv::set_rep_transport(int envid,
int (*send)(DB_ENV *dbenv,
const Dbt *control, const Dbt *rec, int envid, u_int32_t flags));
Description
The DbEnv::set_rep_transport method initializes the communication infrastructure
for a database environment participating in a replicated application.
The envid parameter is the local environment's ID. It must be
a positive integer and uniquely identify this Berkeley DB database environment
(see Replication environment IDs for more
information).
The send parameter is a callback interface used to transmit data
using the replication application's communication infrastructure. The
parameters to send are as follows:
- dbenv
- The enclosing database environment.
- control
- The control parameter is the first of the two data elements to be
transmitted by the send interface.
- rec
- The rec parameter is the second of the two data elements to be
transmitted by the send interface.
- envid
- The envid parameter is a positive integer identifier that
specifies the replication environment to which the message should be
sent (see Replication environment IDs for
more information).
The special identifier DB_EID_BROADCAST indicates that a message
should be broadcast to every environment in the replication group. The
application may use a true broadcast protocol, or may send the message
in sequence to each machine with which it is in communication.
- flag
-
The flags value must be set to 0 or by bitwise inclusively OR'ing together one or
more of the following values:
- DB_REP_PERMANENT
- The record being sent is critical for maintaining database integrity
(for example, the message includes a transaction commit). The
application should take appropriate action to enforce the reliability
guarantees it has chosen, such as waiting for acknowledgement from one
or more clients.
The send interface must return 0 on success and non-zero on
failure. If the send interface fails, the message being sent
is necessary to maintain database integrity, and the local log is not
configured for synchronous flushing, the local log will be flushed;
otherwise, any error from the send interface will be ignored.
It may sometimes be useful to pass application-specific data to the
send interface; see Environment
FAQ for a discussion on how to do this.
The flags parameter is currently unused, and must be set to 0.
The DbEnv::set_rep_transport method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, and returns 0 on success.
Errors
The DbEnv::set_rep_transport method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv::set_rep_transport method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.
See Also
DbEnv::rep_start,
DbEnv::rep_elect,
DbEnv::rep_process_message,
and
DbEnv::set_rep_transport.
Copyright Sleepycat Software
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