Archives of the TeradataForum
Message Posted: Mon, 02 Oct 2012 @ 01:20:39 GMT
| Subj: | | Re: Primary and HSN |
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| From: | | Walter, Todd |
A Hot Standby Node does not move data at all - not to other disk arrays or even to other disks. It is configured such that it has connectivity
to disk arrays that hold the data for the online nodes it protects. When failure of another node occurs in the group of nodes cross connected to
the set of disks, then the AMPs from the failed node are re-instantiated on the HSN and the system is returned to operation. The AMPs on the HSN
can still operate on their data entirely in place with no movement.
This cross connection of IO channels is the reason that the HSN cannot be physically located remotely from the nodes it protects, the IO
connections do not work over long distances.
Teradata has a set of technologies to allow multi-system Teradata systems to be configured geographically remotely from each other. They can be
configured for anything from cold DR to dual active configurations. These technologies include Unity, Data Mover and Teradata Multi-System
Manager.
I recommend a discussion with your local Teradata team to start with a discussion of the availability requirements you are trying to satisfy
followed by a discussion of architectural alternatives to meet those requirements.
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