We tested the operation of Objectivity/DB with a federated database located
on an HPSS-managed NFS mounted file system. The HPSS machine at CACR exported a
filesystem to an HP 755 workstation, where an Objectivity/DB installation was
used to create a federation consisting of two 0.5 MBytes "stars" databases (see
the description of the "stars" application above) located on the mounted
filesystem. The matching application was run successfully. Then the database
bitfiles were forced off HPSS disk and into tape, and the application again run.
This caused an RPC timeout in the Objectivity application during the restore of
the databases from tape to disk. We then inserted a call to "ooRpcTimeout" in
the application, specifying a longer wait time, and re-ran the application
successfully.
In addition, we tested the performance of the NFS-mounted HPSS filesystem for
simple file copies. We copied a 300 MByte file from local disk on the HP 755
workstation into the NFS filesystem, and achieved a data transfer rate of ~330
kBytes/sec. This results shows that the system is reliable for large files, the
data transfer rate approximating the available LAN bandwidth between the HP 755
and the HPSS server machine.