Data Guard Client-side Broker Tips
Oracle Tips by Burleson Consulting
December 3, 2011
Data GuardDonald K. Burleson
Question: What are
the Client Side Components of the Data Guard Broker? I
understand that the data guard broker has both client-side and
server-side components and these work together.
Answer: The Data Guard Manager and Command Line
Interface (DGMGRL) make up the client side components of Data Guard
Broker. Data Guard Manager is a graphical user interface that is
integrated with the Oracle Enterprise Manager (OEM). It contains
several wizards that are used to ease the management of a Data Guard
configuration. DGMGRL or Command Line Interface provides most of the
functionalities of Data Guard Manager and can be useful in writing
custom scripts to automate Data Guard tasks.
Role of the
Transport Network Substrate in broker communication
Oracle SQL*Net services play an important role in
the performance of standby databases. It acts as communication
channel between primary and standby databases. In order for the log
transfer service, automatic archive gap resolution and role
management service to work without manual intervention, an Oracle
Net connection between the primary and the standby site must be
Oracle SQL*Net is not required when a standby
database is running in manual recovery mode. However, given the
limitations and high degree of DBA intervention required in the
manual recovery mode, that particular structure would not be an
SQL*Net can be configured to connect sites over a LAN or a WAN.
Good network bandwidth should be provided in order to achieve better
performance of the log transfer service. In addition to connecting the
primary site to all of its standby sites through SQL*Net, it is a good
practice to connect the standby sites with each other. This will
minimize the downtime during switchover or failover operations.
The Oracle Name services on the primary site should be configured such
that the archiver process can resolve the service name for archiving
to a remote standby destination. Moreover, the listener on standby
sites should be configured properly to respond to the request sent by
the archiver process of the primary site. The details about the
configuration of SQL*Net services in context of Data Guard
configuration are provided in the next chapter.
included a quick architectural overview of the Oracle Data Guard and
standby databases. In general, the following topics were covered in
order to build the foundation for the rest of this book:
- Detail about Oracle processes and files involved
in the working of Data Guard have been presented.
- The redo
log apply service for physical and logical standby databases were
included, in detail.
- A brief description of Log Miner
technology, which forms the backbone of the SQL apply mode, was
- The concept of archive gap sequences and how they
are detected and resolved in Oracle was covered in detail.
complete section on Data Guard Broker provided broker architecture
information along with other core concepts.
- The importance of
SQL*Net in the context of Data Guard has been included, in brief.
A review of the first two chapters should provide a clear picture
of Data Guard and standby databases. Most of the concepts discussed in
these chapters will be elaborated upon in the remainder of this book.