These 4 components work together to provide a full solution that can help you manage your Oracle Standard Edition (SE1, SE and SE2) standby database environment.
In summary, these components perform the following tasks:
- Dbvserver was introduced in Dbvisit Standby version 7 and was completely rewritten in version 8 and further extended in version 9.
- This component is also known as the Central Console - Web-based user interface
- One Central Console to manage multiple Dbvisit Standby version 9 configurations
- Small footprint
- Recommended to install on its own small server (Physical, Virtual Machine or Docker Image - persistent storage required)
- Provides secure encrypted communication - HTTPS protocol on port 4433
- Communicates to Primary and Standby Database servers via the Dbvisit Agent (dbvagent)
- All communication with the Dbvisit Agent is encrypted and secure using passphrase for Dbvagent supplied during initial configuration (this can be updated later)
- Hosts managed by the Central Console can be Windows or UNIX (see the system requirements for more detail)
- The Central Console does have two small repositories where information about tasks being executed are stored, including a new statistics repository in version 9.
- Multiple users can be created and tasks are tracked per user
- Using the Central Console is not required - All functions of Dbvisit Standby version 9 can be run from the Command Line Interface (Standby Core)
- The Dbvisit Agent (dbvagent) is introduced in Dbvisit Standby version 8 and further enhanced in version 9.
- This agent is the link between the Central Console and the Dbvisit Standby Core which must be installed on each database server (primary and standby)
- The Dbvisit Agent has a small footprint and is listening for secure connections on port 7891 from the Central Console
- All communication with the Central Console is secure and encrypted
- The Dbvisit Agent and Central console do not have to be used - some users might only want to use the Command Line Interface (Standby Core) which does not require the Central Console or the Dbvisit Agent. In this case, the Dbvisit Agent does not have to be installed or can be left shutdown.
- The Dbvisit Agent is compulsory to run on a host to be managed by the Dbvisit Standby Central Console
- A small repository is used to keep track of tasks being executed from the Central Console
- The Dbvisit Standby Core is also known as the Command Line Interface
- This is where the core functions of Dbvisit Standby is performed, this include but is not limited to the following functions:
- Creating a Standby Database (CSD)
- Sending and Applying Archived Redo
- Performing Graceful Switchover (Role Reversal)
- Re-synchronize a Standby Database due to unrecoverable archive log gaps or fixing logical corruption on the standby database due to nologging operations that were performed on the primary
- Activate / Failover of a Standby Database when disaster strikes
- More than 80 command line API options
- The Dbvisit Standby Core is making use of the Oracle Instant Client for connecting to the Oracle Database or ASM Instance
- End users might perform minimal installations where only the Dbvisit Standby core is used together with SSH for network communication. In this scenario, no other component needs to be installed and this is considered a Minimal installation and is available as an option if required.
- Since Dbvisit Standby version 8, the previous multiple executables have been combined into one single easy to use command line utility called the Dbvisit Standby Control Utility - "dbvctl"
- For detail help on using the "dbvctl" command use the "-h" option or for full detail on functions use "-h,-f"
- Dbvisit Standby version 9 may still be scheduled, using either the Windows Scheduler or the CRON schedule. The schedule that used to be part of the Dbvserver component has been removed and is no longer available.
- Many of the operations that can be performed by the "dbvctl" utility now allow batch operations - this will help to streamline tasks without interactive questions being asked.
- Dbvnet was introduced in Dbvisit Standby version 7 and has been completely rewritten in version 8 and further extended in version 9.
- Dbvnet is responsible for the network communication between the Oracle Database servers (Primary and Standby).
- All communication between the systems are secure and encrypted (Encryption is on by default and cannot be disabled).
- Dbvnet may be configured to allow compression.
- Dbvnet has two core functions - to allow for the copy of files between servers and to allow for remote execution of commands.
- On Windows-based systems, Dbvnet is the default and only option, whereas Unix based systems have Dbvnet as the default option, but if required, SSH may be used instead of Dbvnet.
The diagram below provides a brief overview of how the above four components work together. The DBA (Administrator) will have the option to either run commands via the Command Line Interface (Standby Core) using the dbvctl utility - or - They can make use of the new Central Console which can be used to manage multiple installations.
Note: The above diagram is just a high-level representation of how Dbvisit Standby components communicate.