Subsections
WANdisco HADR provides high availability (HA) and disaster recovery (DR) for a
software configuration management (SCM)/source code repository like CVS or
Subversion. It allows an SCM user to transparently failover to the next available replica in the event the designated primary SCM server fails. This is achieved using
the WANdisco Failover Agent. The SCM user connects to the WANdisco Failover Agent on the standard SCM port (configurable) like
2401 for CVS,
3690 for Subversion,
80 for Subversion-HTTP. The failover-agent
in turn connects to one of the available WANdisco Replicators. The WANdisco HADR guarantees RPO (Recovery Point Objective) equal to 0 i.e. zero data loss even if the failure happens in the middle of a transaction.
In this administration guide, you will learn how to easily setup
WANdisco HADR as part of a normal WANdisco Replicator install.
- SCM Repository
- Software Configuration Management repository like CVS or Subversion.
- SCM Server
- A network server that provides remote access to an SCM Repository
- Replica
- A repository that is an exact equivalent/copy of another repository.
- Replicator2
- It is the intermediary that acts as an application proxy/gateway between the Failover Agent and a given SCM server. Each Replica has an associated Replicator. It coordinates with other peer replicators to ensure that all replicas of the
SCM repositories stay in sync with each other.
- Failover Agent
- It is the intermediary that acts as an application proxy/gateway between the SCM client and the Replicators. The Failover Agent keeps track of which Replicas are available, and proxies the SCM client's request to one of them.
- Replication Group
- A collection of replicators that work together to keep replicas of a
SCM Repository in sync.
- [replicator] directory
- The base directory under which WANdisco HADR is installed.
- GUID
- Globally Unique Identifier. WANdisco HADR and the underlying Distributed Agreement Engine use 16 byte DCE
UUIDs.
This guide is intended for an SCM administrator or a user who is reasonably
comfortable with:
- Setting up a CVS or Subversion based repository
- Configuring inetd/xinetd service on Unix/Cygwin or Windows service
- Installing Perl and required Perl modules
- Installing Apache 2.0+ server if using Subversion/HTTP protocol
- Installing Java
- Unix or Windows system administration
- Reading the WANdisco HADR and WANdisco Replicator administration guide
cover-to-cover
If you don't meet the above pre-requisites you may want to contact your SCM
administrator or request WANdisco to do a professional install for you.
