#include <db_cxx.h>
 
int
DbEnv::repmgr_start(int nthreads, u_int32_t flags);

The DbEnv::repmgr_start() method starts the Replication Manager.

There are two ways to build Berkeley DB replication applications: the most common approach is to use the Berkeley DB library Replication Manager, where the Berkeley DB library manages the replication group, including network transport, all replication message processing and acknowledgment, and group elections. Applications using the Replication Manager generally make the following calls:

For more information on building Replication Manager applications, please see the Replication Getting Started Guide included in the Berkeley DB documentation.

Applications with special needs (for example, applications using network protocols not supported by the Berkeley DB Replication Manager), must perform additional configuration and call other Berkeley DB replication Base API methods. For more information on building Base API applications, please see the Base API Methods section in the Berkeley DB Programmer's Reference Guide.

Starting the Replication Manager consists of opening the TCP/IP listening socket to accept incoming connections, and starting all necessary background threads. When multiple processes share a database environment, only one process can open the listening socket; the DbEnv::repmgr_start() method automatically opens the socket in the first process to call it, and skips this step in the later calls from other processes.

The DbEnv::repmgr_start() method may not be called before the DbEnv::open() method is called to open the local environment and the DbEnv::repmgr_set_local_site() method is called to configure the local site. In addition, the local environment must be opened with the DB_THREAD flag set.

The DbEnv::repmgr_start() method will return DB_REP_IGNORE as an informational, non-error return code, if another process has previously become the TCP/IP listener (though the current call has nevertheless successfully started Replication Manager's background threads). Unless otherwise specified, the DbEnv::repmgr_start() 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.