B&CC Billmaster

Hot backup subsystem

Backup based on HeartBeat

In B&CC Billmaster there is realized a system of automatic backup - Standby System. It requires the presence of two servers, one of which is primary (Master), and another is standby (Slave). Both servers have an identical suite of software components and settings.

Data are replicated from the primary server to the standby one in real time, for this purpose there are used export drivers of block devices DRBD, and on the physical level GIGABIT Ethernet interface.

On the basis of free SW HeartBeat, a dispatcher keeps track of both servers condition. A dispatcher periodically sends signals to poll the status of COM-port and Ethernet-interface. Absence of response from the primary server within a specified time is considered to be a fault. In this case a dispatcher switches the flow of queries over to the standby server and sends to the personnel a signal about fault of the primary server.

After switching a standby server is available at the IP-address, which was previously used for access to the primary server. This is why switching is unnoticeable for external subsystems.

Both servers have independent uninterrupted power supplies with high capacity. In case of emergency power off these devices ensure operation of servers and backup of the current billing information.

Due to such backup scheme the standby server always has an up-to-date copy of all the billing information and when necessary can undertake functions of the primary server without any data loss. This ensures fault-tolerance of B&CC Billmaster (availability factor is at the level of 0,99999) and steadiness of operators business processes.

Oracle Data Guard backup

The Oracle company offers its own technology of automatic backup of data, which are stored in the Oracle DBMS, for protection from faults, catastrophes, human errors and corruption. This technology is simple and does not require any special hardware for its implementation.

The Standby technology is realized with the help of the program Data Guard, which is included into the standard distribution of Oracle Database. Data Guard allows to create, support and control one or several standby databases. Standby data base is the copy of the primary data base.

Data Guard configuration consists of one primary data base and one or several (up to 9) standby data bases, which, when necessary, can be arranged according to territories. Initially a standby data base is created from a backup copy of the primary or other standby data base. Then Data Guard automatically maintains the standby data base as a transactionally coordinated copy of the primary one. This is reached by carrying and usage of a redo log of the primary data base on a standby system. A redo log represents a sequence of data base blocks modifications on a binary level.

The work pattern of this system is that when a fault occurs on one physical server, there is the possibility to automatically or manually switch over to the standby data base.

Backup of B&CC Billmaster by way of the above methods gives the following main advantages to the operator (provider):

  • efficient use of a network;
  • possibility of use in global networks;
  • higher stability and data protection;
  • higher flexibility;
  • better functionality.