NCI-Sync™ Description

Data Replication at work

NCI-Sync works in concert with a 'file replication' product to keep CONTROL™ or CONTROL-CS™ archives on two HP NonStop nodes in synchronization, and ready for use, in real time.

 

The File Replicator copies files from a source node to a destination node. The inter-node connection can be via EXPAND or TCP/IP. The File Replicator transfers an exact copy of the selected file set on the source node to the destination node, providing a copy of the files on the remote node. The transfer is automatic, keeping the files in synchronization, in near real-time.

The Catalogs and Datafiles that comprise the CONTROL and CONTROL-CS archives contain internal pointers related to file names. When such a file is transferred to another location the internal pointers become invalid, or "fractured".  The internal pointers must be corrected to make the file usable. After the file replicator completes the file transfer, it invokes NCI-Sync to repair the internal pointers within the file.

The file replication program tracks the status of both source and destination copies of each file it is monitoring.  If the link or remote node is becomes unavailable, the replicator records any local status changes. Later, after the trouble is resolved, the replicator transfers the changed files, which are then adjusted by NCI-Sync.

File Replication Programs

The makers of the following products have worked with NCI to ensure that their products operate successfully with NCI-Sync:

• NonStop AutoSYNC™, from HP & Carr Scott Software Inc.
• FileSync™, from TANDsoft Inc.