openHAB for two or more home - openhab

I started exploring openHAB for my home automation. Looks to be a great application for the home automation. I want to automate two homes and want to run openHAB on one centrally placed server. Is it possible to segregate the data for my two homes and provide use based access for two homes.
Or I will have to have to instances running on my server.
Please suggest if anyone has done this earlier.

you can (I believe) provide different sitemaps, but the most importing question is how will a central openhab instance communicate with the "other" home?
Especially If you're going to use bindungs which require a piece of hardware like z-wave etc.
You can potentially play with MQTT and have a small Raspberry Pi running in the "other" home feeding the MQTT.

Assuming that there is not a hardware or range based issue with using OpenHab for two homes (e.g. z-wave USB dongle but second home is out of range) and there is network connectivity between the two houses, there are a number of ways you can accomplish this. Here is one.
The easiest would probably be to just use a naming convention for your items and groups to easily tell which house the item comes from. You would probably want to set up a separate sitemap for each house as well. If I understand your question this should segregate the data for you based on name and provide use based access for each home.
If you want to segregate the data even more thoroughly you can configure your persistence to save all the items from one house to one DB and all the others to a different one, though you will need two different persistence bindings set up (i.e. one uses rrd4j and another uses db4o). I'm not sure this provides any advantage.
The final step is getting the data from the remote house into openHab. How this is accomplished will depend on the nature of the sensors and triggers in the other house. You can use the HTTP binding, TCP/IP binding, or an MQTT broker. I've personally exposed a couple of my Raspberry Pi based sensors to openHAB using a python script and the paho library that publishes the sensor data read from the GPIO pins to an MQTT broker and it works great.

Centralization vs segregation - you have to decide, which one has more advantages and less risk.
The two houses will store data on the server (openhab2, mqtt, DB/rr4d) and each one have access to it - that must be clarified.
The network connectivity is obvious, it should be stable between the two sites. Security is another issue - not only digital, but safety of life (hvac controlling or safety appliances with network outage?).
Configuration is pretty supported in both ways, separate config files (items, rules, persistence, etc) and connectivity in a hierarchy has endless approaches and capabilities.

In the newest version of the android app you can add multiple openhab servers. Why don't just use two instances of openHAB?

Related

Atomic swap in a cross compatibility zone setup

I am pretty new to corda and I am curious if it is possible to do a cross compatibility zone DvP. According to https://www.corda.net/2017/08/compatibility-and-upgrades/ it is possible to have different corda newtorks in a global network.
My question addresses following use case:
let's say I have two corda networks (compatibility zones). Each network has its own notary, nodes, customers & KYC process and is supporting a certain asset.
The first network provides for example a payment infrastructure and the second network a securities network.
Is it possible to do that by using R3 corda, if yes is there any example/tutorial?
Thanks in advance for any support!
The answer is yes but I think we're talking at cross-purposes :) Networks operated and governed by different entities are intended to form and operate WITHIN a compatibility zone.
The way I think it's most helpful to think of Compatibility Zones is to imagine the concept just doesn't exist... imagine there was just ONE Corda network (ie CZ) that everybody used (that was transparently/openly governed so no one firm/group of firms controlled it)... and then all the different apps and business networks existed within it... able to interoperate and transact across each other, because their nodes were compatible... they would understand and accept each other's transactions, etc.
Think about it from the perspective of a firm installing a blockchain node: getting onto any blockchain network (a Corda CZ or whatever the equivalent concept is for other platforms)... getting an identity, punching the right holes in the firewall, setting up the node infrastructure... it's analogous to the work needed to get a firm "on the internet" - setting up routers, getting IP addresses, etc, etc.
It's the kind of thing you want to do once and then reuse ruthlessly. The idea that you would have to connect to an entirely new communications network for each app your firm used would be ludicrous. And yet that's how some people seem to think blockchain deployments should be: ie for each app, you set up a separate blockchain network with its own nodes and settings and identity layer and consensus providers. But that's surely just nonsense, right?
You want to connect to a global network once and then reuse that infrastructure.
So the idea is that we try to have as few CZs as possible and encourage as many business networks as possible to form within that small number of CZs.
I know this can mess with your mind when you first hear about it because all the other enterprise blockchain platforms are going in totally the wrong direction (in my opinion..!) They seem to be encouraging the formation of a separate private network for each application. But that just seems crazy to me.
So maybe try this: even if you think I'm mad, play along with the idea for a day or so and see if it begins to grow on you :) If not, let's debate it again but I really do think this idea of multiple apps on the same overall shared network (ie multiple business networks in a single compatibility zone) is just so amazingly powerful as a concept.
So to your answer: can you do cross-app/cross-business-network DvP within a CZ? Yes! That is one of the key use-cases we invented Corda to solve... it's almost perfect for those sorts of scenarios.
Could you do it if the two apps were on different CZs? Well, yes... but it would be like asking if you could do DvP between assets managed in different databases or hosted on different blockchains.. it's just messier... needing locking and 2PC and all the stuff that we can just eliminate if we hold ourselves accountable for not creating needless balkanisation/siloed deployment through deployment of standalone networks unless they're really, really needed.

How can I get data from a scale into a web application?

*If you think I should ask this question elsewhere, please let me know.
Background:
I need to build an application for converting weights into piece counts. The weights currently come from scales that are connected to PCs via serial ports. I am replacing PC based applications that connect to the scales via a serial connection. I am considering the feasibility of making the next generation of these applications into a web based solution. However, I do not want to do this if it is not a better solution than building an application that runs on the client. In addition, I do not want to use any sort of browser specific technology (ActiveX).
FYI, we currently run a Windows based environment.
What I have so far:
I am currently thinking that I will need some sort of client side “service” to allow the scale data to be retrieved by the web application. I have looked into creating a WCF service for this task and have determined that it would probably work. This would require that the scale be connected to some sort of Windows based computer that is on the network. I would then interface the WCF service (running as a Windows Service on the PC) from an ASP.NET web application running on an IIS web server. This would minimize the footprint on the client and allow us to use a web application.
I am looking for any constructive thoughts and ideas. I am open to reviewing any feasible option that would make this solution as simple and reliable as possible.
Answering my own question per request #honeycomb.
I discovered two viable options for this purpose. Following are high-level overviews of the techniques we leveraged.
Develop a scale reader to be run on a PC connected to the weigh scale device via an RS-232 connection. This reader will forward any information received from the scale into a database. Combined with technologies like change notifications and server-side push notifications, this option will allow data from a weigh scale to be pushed into a web page with little effort and no additional cost. (This option has performed well during testing but is not yet in production)
Invest in converting weigh scale devices to use ethernet connections and connect them to the network. Use an OPC server with a driver that can connect to the weigh scales you are using to read the data from these devices. Consider KEPWare's offering for this purpose. Use KEPWare's tools to forward this data to a database or wherever it is needed. Once again, you can leverage change notifications and server-side push technologies to push this data into web applications in near real-time without polling. (This option is currently working in a critical, production environment)
The second option is probably better in the long-term, but this may vary based on your specific situation. It has some up front costs and would be better suited to new implementations. For my system, I am using the first option because it will ease the transition between the new and old systems.
Note: I am not in any way associated with KEPWare. I am only suggesting their product because it is the only one I am aware of that supports this functionality. I am sure there are other OPC servers that support this type of device.

How do I configure OpenSplice DDS for 100,000 nodes?

What is the right approach to use to configure OpenSplice DDS to support 100,000 or more nodes?
Can I use a hierarchical naming scheme for partition names, so "headquarters.city.location_guid_xxx" would prevent packets from leaving a location, and "company.city*" would allow samples to align across a city, and so on? Or would all the nodes know about all these partitions just in case they wanted to publish to them?
The durability services will choose a master when it comes up. If one durability service is running on a Raspberry Pi in a remote location running over a 3G link what is to prevent it from trying becoming the master for "headquarters" and crashing?
I am experimenting with durability settings in a remote node such that I use location_guid_xxx but for the "headquarters" cloud server I use a Headquarters
On the remote client I might to do this:
<Merge scope="Headquarters" type="Ignore"/>
<Merge scope="location_guid_xxx" type="Merge"/>
so a location won't be master for the universe, but can a durability service within a location still be master for that location?
If I have 100,000 locations does this mean I have to have all of them listed in the "Merge scope" in the ospl.xml file located at headquarters? I would think this alone might limit the size of the network I can handle.
I am assuming that this product will handle this sort of Internet of Things scenario. Has anyone else tried it?
Considering the scale of your system I think you should seriously consider the use of Vortex-Cloud (see these slides http://slidesha.re/1qMVPrq). Vortex Cloud will allow you to better scale your system as well as deal with NAT/Firewall. Beside that, you'll be able to use TCP/IP to communicate from your Raspberry Pi to the cloud instance thus avoiding any problem related to NATs/Firewalls.
Before getting to your durability question, there is something else I'd like to point out. If you try to build a flat system with 100K nodes you'll generate quite a bit of discovery information. Beside generating some traffic, this will be taking memory on your end applications. If you use Vortex-Cloud, instead, we play tricks to limit the discovery information. To give you an example, if you have a data-write matching 100K data reader, when using Vortex-Cloud the data-writer would only match on end-point and thus reducing the discovery information by 100K times!!!
Finally, concerning your durability question, you could configure some durability service as alignee only. In that case they will never become master.
HTH.
A+

Rerouting Application Network Traffic at the Data Link Layer

Consider the following situation:
You have an application you are tesing, but in order to test the networking functionality of said program, you are required to run multiple instances of it and have them communicate with one another.
Possible solutions are:
- Run software on individual machines connected by WAN or LAN.
- Run the software on virtual machines, all on the same computer.
I do not want to use either of these methods (the reasoning is irrelevant). I want to know if there is a way that I can reroute network transmissions from the test application (ideally in any programmming language) in a way such that I can run multiple instances of the same software on one computer, and have them behave as if they were the only instance running on that computer.
In other words, I want to be able to code the application so that each instance listens on the same "listening" port (since only one instance will be running on each computer when in production). Then, I want to know if I can reroute the network requests at a lower level then the application so that they do not interfere with eachother (clash over the same port number).
Essentially, I want to build a virtual environment which only redirects the network calls (whereas a virtual machine takes far more resources, and has way more involved). Is this possible, and how might I approach this problem?
Thank you!
UPDATE: This is a more accurate idea of what I want to accomplish:
Basically, I want to program another application which TRANSPARENTLY redirects bind requests to available ports, and manages which applications are bound where... So from the applications perspective, all the instances are bound to port 1000, but in reality, this other application is automatically managing which instance is bound where, and avoiding potential conflicts. I feel like this could be accomplished with Windows Hooks, but I'm not sure how you could implement this?
As far as I know, there is no sane way to multiplex the same port on the same network device. At the very minimum, you will need to choose on of the following:
Run each instance of your program on a different port
Create multiple virtual network interfaces
The first choice is easy and may be the one I would choose. The second one is more towards what you are looking for but it would be a true PITA to set up - you can look into VirtualBox and its host-only networks for inspiration. If you are writing things on linux you might look into pipes and chrooting but you'll be spending more time setting up this environment than writing your software.

Distributed C++ game server which use database

My C++ turn-based game server (which uses database) does not stand against current average amount of clients (players), so I want to expand it to multiple (more then one) amount of computers and databases where all clients still will remain within single game world (servers will must communicate with each other and use multiple databases).
Is there some tutorials/books/common standards which explain how to do it in a best way?
The way you put the database into the picture might be misleading: clustering solutions exist for all of the mostly used RDBMS, so that if you need to support your DB activities with more than one DB node you will just have to check the documentation from your DB vendor.
More complex scenarios are there when it comes to synchronize your non-DB application state that needs to be shared among several servers. There are already a number of questions here that tackle the same problem, like here or here
You might also be interested into some messaging system, I heard good things about ZeroMQ
Hope this helps.

Resources