Hi Takenori, Sounds good! Thanks for using HTM.java! Please remember to update to version v0.6.4-alpha as there have been some important updates (yesterday).
1. timestamp should be periodic? The timestamp can have gaps but not go backwards. It must be progressive, but not necessarily periodic. 2. one model for each node? Yes. "Model" in HTM.java's world means "Network". Operation of HTM.java is exactly the same as NuPIC in terms of its capability. So as far as I know, a separate model is needed for every predicted element. (I may be wrong about this - so if there are any doubts you should ask Matt Taylor (a.k.a. @rhyolight) or one of the other Numenta engineers. As an added note - I'm in the curious position of being an expert at knowing the code (both Python and Java), but I have very little experience actually using NuPIC to get things done... It's a symptom of being laser focused on code production - I haven't had time to actually use anything much. (Although that is slowly changing and I'm getting a bit of experience under my belt). Good luck with your project, and as always the NuPIC Community is willing to help! Cheers, David On Fri, Oct 23, 2015 at 10:00 PM, Takenori Sato <[email protected]> wrote: > Hi David, > > Your feedback is encouraging! > > Especially on a geographically distributed environment(e.g. cars as IoT > clients, and its backends for analytics), such an algorithm based on a > static threshold is not robust enough against various noises over data > centers. > > I expect HTM is very robust against such noises. > > OK, then I will use HTM for this subject, staring with embedding HTM.java > in Cassandra, and see how much it gets improved. > > Btw, I have some questions regarding the input format. > > 1. timestamp should be periodic? > > Should I give inputs periodically, at a fixed interval? Then, I need to > take an average response time(or max if not available) for a period. > > e.g. > timestamp(fixed interval), an average response time, node > > Or, can I simply feed as a health check response arrives? > > e.g. > timestamp(variable), response time, node > > 2. one model for each node? > > To get anomaly score for each node, do I need to have one model for each > node? > > Thanks, > Takenori > > On Fri, Oct 23, 2015 at 9:03 PM, cogmission (David Ray) < > [email protected]> wrote: > >> Hi Takenori, >> >> In my opinion (due to the constant time related pinging nature of the >> health checks), is YES :-) HTM is **perfect** for this... Very interesting >> application of NuPIC technology, by the way! >> >> Cheers, >> David >> >> On Fri, Oct 23, 2015 at 2:13 AM, Takenori Sato <[email protected]> >> wrote: >> >>> Hello, >>> >>> In a distributed system, it is very important to know which node is more >>> healthier than others to make a request. Or of course, when to determine >>> one node should be treated as dead. >>> >>> For example, cassandra relies on phi accrual detector[1] to detect node >>> down. A node does a gossip communication with 3 nodes every second, and >>> exchanges information with each other. And its response time is used as an >>> input for the failure detection. >>> >>> Also, a badness score is computed with such information, and which is >>> used to choose a healthier node among replica nodes. >>> >>> But, I have seen many situations when it didn't work as expected, >>> especially choosing a healthier node. >>> >>> On the other hand, I know any service provider makes some kind of health >>> check request to detect if service is available or not. It may be just a >>> simple ping, or HEAD request. >>> >>> Then, I just wondered if it is a good use case to use HTM for failure >>> detection with such simple health check requests? >>> >>> For example, its input looks like this: >>> >>> time, node, avg response time(ms) >>> 10:00:00, node1, 10 >>> 10:00:00, node2, 9 >>> ... >>> 10:00:30, node1, 15 >>> 10:00:30, node2, 10 >>> ... >>> >>> >>> [1] http://www.jaist.ac.jp/~defago/files/pdf/IS_RR_2004_010.pdf >>> >>> Thanks, >>> Takenori >>> >> >> >> >> -- >> *With kind regards,* >> >> David Ray >> Java Solutions Architect >> >> *Cortical.io <http://cortical.io/>* >> Sponsor of: HTM.java <https://github.com/numenta/htm.java> >> >> [email protected] >> http://cortical.io >> > > -- *With kind regards,* David Ray Java Solutions Architect *Cortical.io <http://cortical.io/>* Sponsor of: HTM.java <https://github.com/numenta/htm.java> [email protected] http://cortical.io
