This is a strange one. A patent troll has a patent so diffuse that it is almost meaningless and is suing RedHat over it:
“Network Distributed Caches (“NDCs”) (50) permit accessing a named dataset stored at an NDC server terminator site (22) in response to a request submitted to an NDC client terminator site (24) by a client workstation (42). In accessing the dataset, the NDCs (50) form a NDC data conduit (62) that provides an active virtual circuit (“AVC”) from the NDC client site (24) through intermediate NDC sites (26B, 26A) to the NDC server site (22). Through the AVC provided by the conduit (62), the NDC sites (22, 26A and 26B) project an image of the requested portion of the named dataset into the NDC client site (24) where it may be either read or written by the workstation 42. The NDCs (50) maintain absolute consistency between the source dataset and its projections at all NDC client terminator sites (24, 204B and 206) at which client workstations access the dataset. Channels (116) in each NDC (50) accumulate profiling data from the requests to access the dataset for which they have been claimed. The NDCs (50) use the accumulated profile data stored in channels (116) to anticipate future requests to access datasets, and, whenever possible, prevent any delay to client workstations in accessing data by asynchronously pre-fetching the data in advance of receiving a request from a client workstation.
It’s almost gibberish. The nearest I can gather is that they have a patent on the network cache like Squid or nscd. No doubt RedHat uses such things in its clustering setups. Squid was developed around 1996 and the damned patent was “filed” around 1997.
In the patent application itself mention is made of NFS file caching and BSD4.3. The claim is made that the “invention” improves cache coherency although it does not shed much light on how that works. The filing date is also shown as February 26, 1997.
BSD 4.3 was released in 1986, so nothing here looks innovative beyond the state of the art. I expect RedHat will be able to show:
- the invention is not patentable (obviousness and prior art),
- the invention does not work as described, for example does not work any better than some prior art,
- the invention is essentially no different than a mail-server such as sendmail which was developed around 1979-1980. Sendmail caches mail and synchronizes a bunch of clients via SMTP. POP is another mail protocol. The RCEV operation of POP downloads the e-mail but leaves it on the server/cache,
- the invention is essentially no different than NFS which used a cache even in version 1 from 1989,
- the inventor invented nothing not already in the prior art:“The threshold question in determining inventorship is who conceived the invention. Unless a person contributes to the conception of the invention, he is not an inventor”,
- the invention has no written description sufficient to implement the invention. In particular, “projecting an image of data” is not defined (“each NDC site including an NDC that has an NDC buffer, a method for projecting an image of a stored dataset”),
- RedHat does not use it (the preferred implementation requires multiple daemons, long delays which cannot speed anything up), and
- since RedHat is FLOSS, the inventor obviously ignored the violation until now, evidence that there is no violation.
I trust the judge will laugh this one out of court and send the troll the bill for cluttering up the court system.