Function putSlaveOnline

src/replication.cpp:1772–1805

This function puts a replica in the online state, and should be called just * after a replica received the RDB file for the initial synchronization, and * we are finally ready to send the incremental stream of commands. * * It does a few things: * 1) Close the replica's connection async if it doesn't need replication * commands buffer stream, since it actually isn't a valid replica. * 2)

 *    sending it to the replica.
 * 4) Update the count of "good replicas". */
void putSlaveOnline(client *replica) {
    replica->replstate = SLAVE_STATE_ONLINE;
    
    replica->repl_put_online_on_ack = 0;
    replica->repl_ack_time = g_pserver->unixtime; /* Prevent false timeout. */

    if (replica->flags & CLIENT_REPL_RDBONLY) {
        serverLog(LL_NOTICE,
            "Close the connection with replica %s as RDB transfer is complete",
            replicationGetSlaveName(replica));
        freeClientAsync(replica);
        return;
    }
    if (connSetWriteHandler(replica->conn, sendReplyToClient, true) == C_ERR) {
        serverLog(LL_WARNING,"Unable to register writable event for replica bulk transfer: %s", strerror(errno));
        freeClient(replica);
        return;
    }
    refreshGoodSlavesCount();
    /* Fire the replica change modules event. */
    moduleFireServerEvent(REDISMODULE_EVENT_REPLICA_CHANGE,
                          REDISMODULE_SUBEVENT_REPLICA_CHANGE_ONLINE,
                          NULL);
    serverLog(LL_NOTICE,"Synchronization with replica %s succeeded",
        replicationGetSlaveName(replica));
    
    if (!(replica->slave_capa & SLAVE_CAPA_ACTIVE_EXPIRE) && g_pserver->fActiveReplica)
    {
        serverLog(LL_WARNING, "Warning: replica %s does not support active expiration.  This client may not correctly process key expirations."
            "\n\tThis is OK if you are in the process of an active upgrade.", replicationGetSlaveName(replica));
        serverLog(LL_WARNING, "Connections between active replicas and traditional replicas is deprecated.  This will be refused in future versions."
            "\n\tPlease fix your replica topology");
    }
}

/* We call this function periodically to remove an RDB file that was
 * generated because of replication, in an instance that is otherwise