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Dbvisit Standby Architecture and Components

Before we talk about Dbvisit Standby and it’s components, let’s talk little bit about about Disaster Recovery and Business Continuity.


What is Business Continuity?

In the event of a disaster, the process of failing over your server from the primary to the secondary site is known as Disaster Recovery. A disaster recovery solution provides your Company with Business Continuity.

The main purpose of Dbvisit Standby is to provide the Organizations with greater Business continuity.



What is Physical Replication?

The process of creating a Standby database from the source or primary database is known as Physical Replication. The Standby database is kept in sync using the archive logs generated on the source database to ensure that the Standby database is an exact copy of the source database.



How to Configure Disaster Recovery environment with Dbvisit Standby?

The following are the Disaster Recovery Configurations options available:
  1. On-Premise to On-Premise
  2. On-Premise to Cloud
  3. Cloud to On-Premise
  4. Cloud to Cloud

Dbvisit Standby Architecture

These are four main components that make up Dbvisit Standby’s Architecture.
  • Dbvserver
  • Dbvagent
  • Dbvnet
  • Standby core


Dbvserver:

It hosts secure web based user interface for Dbvisit standby. Multiple users can manage various different DR configurations. It provide graphical overview of setup, running and reporting of DR sites. It is recommended to that Dbvserver which has a small footprint be installed on different server.

Dbvserver details:
Using a small VM machine should be sufficient
HTTPS protocol port 4433
Host Managed by Dbvserver can be Windows or Linux
It has a small repository where information about executed tasks are store
It support Chrome, FireFox and Safari browsers

Dbvagent:

It is used to manages the communication between Dbvserver (web based user interface) and Dbvisit Standby core. Communication between Dbvagent and Dbvserver is encrypted. Dbvisit agent has a small footprint and listens for secure connection on port 7891 from the central console. The Dbvisit agent must run on the host managed by the Dbvisit Standby Central console. A user can bypass Dbvserver web based user interface and directly access CLI if preferred. In this case Dbvisit agent does not have to be installed or can be left shutdown.

Dbvnet:

It is responsible for secure communication between primary and standby systems. It essentially provides an encrypted transport layer to copy files and execute remote commands between primary and standby database server. It runs on both primary and standby servers and configured during installation process. Dbvnet removes any dependency SSH had for providing network communication  between primary and standby nodes. It is started as background process and it runs independently from the Dbvserver and Dbvagent.

Dbvisit Standby Core:

It is also known as command line interface. It is the heart of Dbvisit standby. This is where all commands are run to enable Dbvisit Standby to function. A user can bypass Dbvserver web based user interface and directly access CLI if preferred.

Dbvisit Standby Core allow you:

  •     Create standby database (CSD)
  •     Extract and Send archive logs to standby (SEND)
  •     Recover standby database using shipped archived logs (RECOVER)
  •     Perform Graceful Switchover also known as role reversal (GS)
  •     Synchronize a standby database (SYNC)
  •     In case of disaster activate the standby database (FAILVOER)
  •     It also provide API options, more than 80 command line API options (API)

dbvctl : The Dbvisit Standby Control CLI Utility



Other Dbvisit Standby Components

  • Database Configuration File (DDC)
Contains the Dbvisit Standby setting for a specific primary and standby pair.
Generated during the setup for each database.
can be edited with any text editor or by running ‘dbvisit -o setup’ or through web based GUI

  • Database Repository (DDR)
This is repository used by Dbvisit Standby to store internal information about Dbvisit Standby Configuration and functionality being performed.
It is a small *.db file located in the standby/conf sub directory.

  • Trace Files
Contains information about Dbvisit standby processing.
These files are required by Dbvisit Support in the event when an error is raised.
They are located in the standby/trace sub directory.



Dbvisit Standby functionality

Dbvisit Standby follows a simple 3 Steps functionality. The same is illustrated in the picture below:

Step 1: Log Extraction : Dbvisit Standby will extract the primary database archive logs from the database archive destination.
Step 2: Transport : The second step in the process will be to copy these extracted archive logs to the standby site.
Step 3: Log Apply : The third step in the process is Dbvisit Standby applying the transferred archive logs to the standby database.




Dbvisit Standby on Oracle RAC

  • Dbvisit Standby can be used together with Oracle RAC (Real Application Cluster)
  • Oracle RAC together with Dbvisit Standby standby database(s) allows scalability and provides high availability and disaster recovery
  • Dbvisit Standby supports archive logs in Oracle ASM (Automatic Storage Management) file system
  • The standby database can be a RAC or Non-RAC standby database


Conclusion

In this article we have learned Dbvisit Standby Architecture, different Dbvisit Standby components and Dbvisit Standby functionality.