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DbEnv::rep_process_message
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#include <db_cxx.h>
int
DbEnv::rep_process_message(Dbt *control, Dbt *rec, int *envid)
Description
The DbEnv::rep_process_message method processes an incoming replication
message sent by a member of the replication group to the local database
environment.
The rec and control parameters should reference a copy
of the parameters specified by Berkeley DB for the rec and
control parameters on the sending environment.
The envid parameter should contain the local identifier that
corresponds to the environment that sent the message to be processed
(see Replication environment IDs for more
information).
For implementation reasons, all incoming replication messages must be
processed using the same DbEnv handle. It is not required that
a single thread of control process all messages, only that all threads
of control processing messages use the same handle.
The DbEnv::rep_process_message method may return one of several special conditions:
- DB_REP_DUPMASTER
- The replication group has more than one master; the application should
reconfigure itself as a client by calling the DbEnv::rep_start method, and
then call for an election by calling DbEnv::rep_elect.
- DB_REP_HOLDELECTION
- An election is needed, the application should call for an election by
calling DbEnv::rep_elect.
- DB_REP_NEWMASTER
- A new master has been elected. The memory location referenced by the
envid parameter contains the environment ID of the new master.
If the recipient of this error return has been made master, it is the
application's responsibility to begin acting as the master environment.
- DB_REP_NEWSITE
- The system received contact information from a new environment. The
rec parameter contains the opaque data specified in the
cdata parameter to the DbEnv::rep_start. The application
should take whatever action is needed to establish a communication
channel with this new environment.
- DB_REP_OUTDATED
- The current environment's logs are too far out of date with respect to
the master to be automatically synchronized. The application should
copy over a hot backup of the environment, run recovery, and restart
the client.
Otherwise, the DbEnv::rep_process_message 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::rep_process_message 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::rep_process_message 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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