#include <db.h>

int
DB_ENV->rep_process_message(DB_ENV *env,
    DBT *control, DBT *rec, int *envid)

Description

The DB_ENV->rep_process_message function 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 DB_ENV 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 DB_ENV->rep_process_message function 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 DB_ENV->rep_start function, and then call for an election by calling DB_ENV->rep_elect.

DB_REP_HOLDELECTION

An election is needed, the application should call for an election by calling DB_ENV->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 DB_ENV->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The current environment's logs are too far out of date with respect to the master to be automatically synchronized.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 DB_ENV->rep_process_message function returns a non-zero error value on failure and 0 on success.

Errors

The DB_ENV->rep_process_message function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the DB_ENV->rep_process_message function may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

See Also