I would like to use the apache-jena-fuseki server to provide an ontology within a local network environment. And as such it should be editable from all machines in the LAN ideally via a webinterface (for simplicity).
The built-in webinterface of apache-jena-fuseki is doing that job well, BUT only from the machine running the server. Accessing the webinterface from other machines will somehow not provide the functionalities of managing (uploading & deleting) the datasets.
Is this a configuration issue? And, if yes, how and where should it be modified?
Any help on the matter is highly appreciated!
Cheers!
Related
I'm setting up an XNAT server using their container service. But I want to archive my files in a separated server/NAS.
Has anyone done this before? Any tutorial on this?
Thanks.
From my search:
"The easiest way to do this would be to mount the location on your NAS where you want the data to be archived to the location of the archive folder on your XNAT server. You can probably configure your containers to run so that they write data directly to the NAS storage rather than to your XNAT server. That would reduce network traffic, since writing to the XNAT server directly would then require sending the data across the network connection to the NAS. That said, I have no idea how to do that part and will defer to Flavin et al as far as configuring how your containers interact with the archive space."
I'm compiling things on a raspberry pi and it's not going fast enough, even when I use my desktop's CPU to help.
I could just install distcc the old fashioned way on a cloud server, but what if someday I was to real quick spin up a bunch of servers for a minute with docker machine?
distccd can use SSH auth, but I don't see a good way to run both SSH and distccd. And it seems there will be hassle with managing ssh keys.
What if configured distcc to only accept the WAN IP of my house (and then turned the image off as soon as it was done)?
But it'd be great to make something other raspberry pi users could easily spin up.
You seem to already know the answer to this, set up distcc to use SSH. This will ensure encrypted communication between your distcc client and the distcc servers you have deployed as Docker images in the cloud. You have highlighted that the cost of doing this would be spending time to set up an SSH key that would be accepted by all of your Docker images. From memory this key could be the same for all the Docker nodes, as long as they all had the same user name using the same key. Is that really such a complex task?
You ask for a slightly less secure option for building your Compile Farm. Well limiting things based on the Internet accessible IP address for your house would limit the scope and increase the complexity of others using your build cluster. Someone might spoof the special IP address and get access to your distcc servers but that would just cost you their runtime. The larger concern would be that your code could be transmitted in plain text over the internet to these distcc servers. If that is not a big concern then it could be considered low risk.
An alternative might be to setup a secure remote network of docker nodes and set up VPN access to them. This would bind your local machine to the remote network and you could consider the whole thing to be a secured LAN. If it is considered safe to have the Docker nodes talk between themselves in an unencrypted manner within the cloud, it should be as secure to have a VPN link to them and do the same.
They best option might be to dig out a some old PCs and set those up as local distcc servers. Within a LAN their is no need for security.
You mention a wish to share this with other Raspberry PI users. There have been other Public Compile Farms in the past but many of them have fallen out of favour. Distributing such things publicly, as computational projects such as BOINC do, works poorly because the network latency and transfer rates can slow the builds significantly.
I am looking to write a program that will connect to many computers from a single computer. Sort of like "Command Center" where you can monitor all the remote system remotely on a single PC.
My plan is to have multiple Client Sockets on a form. They will connect to individual PCs remotely. So, they can request information from them to display on the Window. Remote PCs will be hosts. Is this possible?
Direct answer to your question: Yes, you can do that.
Long answer: Yes, you can do that but are you sure your design is correct? Are you sure you want to create parallel connections, one to each client? Probably you don't! If yes, then you probably want to run them in separate threads.
If you want to send some commands from time to time (and you are not doing some kind of constant video monitoring) why don't you just use one connection and 'switch' between clients?
I can't tell you more about the design because from your question is not clear about what you want to build (what exactly you are 'monitoring').
VERY IMPORTANT!
Two important notices to take into account before designing your app (both relevants only if the remote computers are not in the LAN (you connect to them via Internet)):
If the remote computers are running as servers, you will have lots of problems to explain your customers (if they are connected (and they probably are) to Internet via a router) how to setup the router and the software firewall. For example, if a remote computer is listening for commands from you, on port 1234 (for example) the firewall in the router will block BY DEFAULT any connection attempt from a 'foreign' computer (from you) to that port.
If your remote computers are running as clients, how they will know master's IP (your IP). Do you have a static IP?
What you actually need is one ServerSocket on the module running on your machine.
To which all your remote PC's will connect through their individual ClientSocket.
You can make your design other way round by putting ClientSocket on the module running on your machine and ServerSocket on the module running on remote machine.
But you will end up creating one ClientSocket to each ServerSocket, what if you have the number of remote servers increase.
Now if you still want to have multiple ClientSockets on your machine then as Altar said you could need a multi threaded application where each thread is responsible for one ClientSocket.
I would recommend Internet Direct (Indy) as they work well in threads, and you can specify a connect time-out per connection, so that your monitoring app will be able to get a 'negative' test result faster than with the default OS connect time-out.
Instead of placing them on the form, I would wrap each client in a class which runs an internal monitoring thread. More work initially but easier to keep independent from each other.
I have an application that connects to a database and can be used in multi-user mode, whereby multiple computers can connect the the same database server to view and modify data. One of the clients is always designated to be the 'Master' client. This master also receives text information from either RS232 or UDP input and logs this data every second to a text file on the local machine.
My issue is that the other clients need to access this data from the Master client. I am just wondering the best and most efficient way to proceed to solve this problem. I am considering two options:
Write a folder synchronize class to synchronize the folder on the remote (Master) computer with the folder on the local (client) computer. This would be a threaded, buffered file copying routine.
Implement a client/server so that the Master computer can serve this data to any client that connects and requests the data. The master would send the file over TCP/UDP to the requesting client.
The solution will have to take the following into account:
a. The log files are being written to every second. It must avoid any potential file locking issues.
b. The copying routine should only copy files that have been modified at a later date than the ones already on the client machine.
c. Be as efficient as possible
d. All machines are on a LAN
e. The synchronization need only be performed, say, every 10 minutes or so.
f. The amount of data is only in the order of ~50MB, but once the initial (first) sync is complete, then the amount of data to transfer would only be in the order of ~1MB. This will increase in the future
Which would be the better method to use? What are the pros/cons? I have also seen the Fast File Copy post which i am considering using.
If you use a database, why the "master" writes data to a text file instead of to the database, if those data needs to be shared?
Why invent the wheel? Use rsync instead. Package for windows: cwrsync.
For example, on the Master machine install rsync server, and on the client machines install rsync clients or simply drop files in your project directory. Whenever needed your application on a client machine shall execute rsync.exe requesting to synchronize necessary files from the server.
In order to copy open files you will need to setup Windows Volume Shadow Copy service. Here's a very detailed description on how the Master machine can be setup to allow copying of open files using Windows Volume Shadow Copy.
Write a web service interface, so that the clients an connect to the server and pull new data as needed. Or, you could write it as a subscribe/push mechanism so that clients connect to the server, "subscribe", and then the server pushes all new content to the registered clients. Clients would need to fully sync (get all changes since last sync) when registering, in case they were offline when updates occurred.
Both solutions would work just fine on the LAN, the choice is yours. You might want to also consider those issues related to the technology you choose:
Deployment flexibility. Using file shares and file copy requires file sharing to work, and all LAN users might gain access to the log files.
Longer term plans: File shares are only good on the local network, while IP based solutions work over routed networks, including Internet.
The file-based solution would be significantly easier to implement compared to the IP solution.
I want to create a client server application to test socket created and threads are running between client and server.
I want to check this for internet application.
But being on local machine. I cannot check.
You could run a virtual machine on your real machine and a bridge-mode network connection between the two. Then run the server on one and the client on the other.
However, you will not get a good picture of how well it responds under heavily loaded network conditions. For that you truly need a private network with a phantom load generator.
VirtualBox, VirtualPC, and vmware can do this. You might get better/more responses on superuser.com.