I'm trying to implement peer-to-peer messaging and file sharing utility within LAN, So does WCF supports p2p? Does any one tried file sharing trough WCF?
Yes, it does. Please see How To Design State Sharing In A Peer Network:
When researching the various ways in
which an election scenario might be
implemented, I discovered that there
is an attribute in WCF that allows you
to indicate the maximum number of hops
that a particular message will travel.
After seeing this, it became obvious
that there was a means for sharing
state in a peer network that not only
required no central server, but was
resilient to node drop-off and did not
require election. I call it Nearest
Peer Synchronization.
Yes. Check out the NetPeerTCPBinding.
Related
Both Pipes and ASP.NET Core gRPC support local and remote IPC/RPC (with some platform limitations for gRPC)
When would I use one technology (Pipes) or the other (gRPC)?
Observations, thoughts and considerations I'm keeping in mind:
gRPC seems to be geared towards replacing WCF in some future iteration.
local deployments and with machine restrictions (running as non-admin/user, machine firewalls, different platforms/OS)
network traversal, and compatibility with same-machine -> multi-machine (frontend/backend arrays) for load and expansion
Spanning secure zones (where a Proxy is used, or other TLS cipher/order/registry setting) affects the ability for HTTP/2 to work
Pipes (named pipes?) have a different surface area and port (do they also use port 135, or NetBIOS over TCP (not sure of name))... how is it scanned and secured?
"memory mapped files" seem to be a challenge to get working, however it seems to work in ASP.NET Core with gRPC in the UDS configuration. Is this a correct inference?
Right now my scenario is to have two console apps communicate with each other, same machine or remote. Adding Asp.NET Core Web is an optional front end alternative for my scenario.
Simple IPC
Depends on how much communication is going to happen. If your communication is limited to simple collaborative signal passing or sharing some data between two processes you can safely use NamedPipeClientStream and NamedPipeServerStream on local system or local network but if you plan for the same on different systems then I would suggest using TcpClient and TcpListener.
Comprehensive IPC
WCF or now its replacement gRPC is for scenario where a complete API/Framework need to be executed remotely. For example I have an entire library of classes which I need to call from a different process (which mostly run on a different system); in that case gRPC kind of solutions make more sense.
Only you can decide.
This is a design decision which is highly unique for your application; your future plans and your system environment and any third person can only give you clues but ultimately you are the only person who can make the right decision.
I have a configuration where 3 applications run on 3 different Virtual Machine's and they must communicate via DDS i.e. RTPS protocol.
The configuration is as follows :
ROS2 based ADAS functions
Simulation Tool
Python/Tensorflow based machine learning functions
All 3 need to be on different VMs.
It is not possible at our end to allow multicasting for the MS AZURE VM and our network.
Here are some questions :
Is it still possible to communicate via DDS ?
If yes, through UNICAST i.e. peer to peer connection ?
Is using DDS communication beneficial in this case if i already have the option of basic UDP socket programming ?
Could you think of any restrictions/ further problems in using DDS for such a configuration ?
Is it still possible to communicate via DDS ?
Yes, it is. Out of the box, DDS Participants only use multicast for discovering other DDS Participants, at startup. This discovery mechanism can be configured in several ways. For a an explanation on how to achieve that, see this RTI Community Knowledge Base article: Configure RTI Connext DDS to not use Multicast.
If yes, through UNICAST i.e. peer to peer connection ?
Yes, with the no-multicast setup, all communications are done over UDP unicast, peer to peer, connectionless.
Is using DDS communication beneficial in this case if i already have the option of basic UDP socket programming ?
Not being able to use multicast does not remove any of the DDS advantages when comparing it to UDP. When using DDS, the transport/discovery configuration is typically invisible to the application and all Publish/Subscribe concepts remain unchanged.
If you are asking about the advantages of using DDS versus UDP, I think that warrants a new question on itself. The answer will be quite extensive :-)
Could you think of any restrictions/ further problems in using DDS for such a configuration ?
With this configuration, your configuration settings will be dependent on the network that you are running on. This means that migration to a different network might need reconfiguration, for example providing different host names or IP addresses. This is inconvenient, but not hard.
Since your environment is restricting the use of multicast, I would not be surprised if there are more restrictions that you have not mentioned or discovered. For example, do you know anything about firewalls or network bandwidth restrictions? Again, DDS can be configured to deal with such things, but you need to be aware of them first.
I have explored the web on MULE and got to understand that for Apps to communicate among themselves - even if they are deployed in the same Mule instance - they will have to use either TCP, HTTP or JMS transports.
VM isn't supported.
However I find this a bit contradictory to ESB principles. We should ideally be able to define EndPoints in and ESB and connect to that using any Transport? I may be wrong.
Also since all the apps are sharing the same JVM one would expect to be able to communicate via the in-memory VM queue rather than relying on a transactionless HTTP protocol, or TCP where number of connections one can make is dependent on server resources. Even for JMS we need to define and manage another queue and for heavy usage that may have impact on performances. Though I agree if we have distributed and clustered systems may be HTTP or JMS will be only options.
Is there any plan to incorporate VM as a inter-app communication protocol or is there any other way one Flow can communicate with another Flow Endpoint but in different app?
EDIT : - Answer from Mulesoft
http://forum.mulesoft.org/mulesoft/topics/concept_of_endpoint_and_inter_app_communication
Yes, we are thinking about inter-app communication for a future release.
Still is not clear when we are going to do it but we have a couple of ideas on how we want this feature to behave. We may create a server level configuration in which you can define resources to use in all your apps. There you would be able to define a VM connector and use it to send messages between apps in the same server.
As I said, this is just an idea.
Regarding the usage of VM as inter-app communication, only MuleSoft can answer if VM will have a future feature or not.
I don't think it's contradictory to the ESB principle. The "container" feature is pretty well defined in David A Chappell's "Enterprise Service Bus book" chapter 6. The container should try it's best to keep the applications isolated.
This will provide some benefits like "independently deployable integration services" (same chapter), easier clusterization, and other goodies.
You should approach same VM inter-app communications as if they where between apps placed in different servers.
Seems that Mule added in 3.5 version, a feature to enable communication between apps deployed in the same server. But sharing a VM connector is only available in the Enterprise edition.
Info:
http://www.mulesoft.org/documentation/display/current/Shared+Resources#SharedResources-DefiningDomains
Example:
http://blogs.mulesoft.org/optimize-resource-utilization-mule-shared-resources/
Just a technology update, now that .NET 4.0 is out.
I write an application that communicates to the server through what is basically a message bus (instead of method calls). This is based on the internal architecture of the application (which is multi threaded, passing the messages around).
There are a limited number of messages to go from the client to the server, quite a lot more from the server to the client. Most of those can be handled via a separate specialized mechanism, but at the end we talk of possibly 10-100 small messages per second going from the server to the client.
The client is supposed to operate under "internet conditions". THis means possibly home end users behind standard NAT devices (i.e. typical DSL routers) - a firewalled secure and thus "open" network can not be assumed.
I want to have as little latency and as little overhad for the communication as possible.
What is the technologally best way to handle the message bus callback? I Have no problem regularly calling to the server for message delivery if something needs to be sent...
...but what are my options to handle the messagtes from the server to the client?
WsDualHttp does work how? Especially under a NAT scenario?
Just as a note: polling is most likely out - the main problem here is that I would have a significant overhead OR a significant delay, both aren ot really wanted. Technically I would love some sort of streaming appraoch, where the server can write messags to a stream while he generates them and they get sent to the client as they come. Not esure this is doable with WCF, though (if not, I may acutally decide to handle the whole message part outside of WCF and just do control / login / setup / destruction via WCF).
For bidirectional communications, your best bet is NetTcpBinding, rather than the http bindings, if they're available.
This has the advantage of only requiring that the client can initiate a connection with the server.
I would go with Windows Azure Service Bus. See my answer in the following question:
WCF, 4.0, Bidirectional
Take a look at Windows AppFabric, good place to start is Here. It fundamentally wraps up WCF and WF into an application server, with WCF activation supported through WAS. Its where I would host this type of app. It offerd full duplex connection orientated, p2p or sessions between client and server. Don't confuse the Windows appfabric with Azure appfabric, (formely called Azure Service Bus).
As regards bindings above, both NetTcpBinding and WsDualHttp offer callbacks, but the ws binding you get a lot for your cash, especially if it's a mixed programming environment and you have to flatten the wsdl to make interop work. I also think that WsDual is easier on routers traversal, although I understand talking to friends, that Windows AppFabric mitigates this, with new Relay Services, (which i've not seen, and I think have now been renamed).
Hope that helps.
Just curious to know what your experiences with PNRP are? I have been using WCF to code up a peer to peer application using WCF.
I support 2 different setups, one using PNRP (i.e. no server) and another setup using a central server.
The central server approach is really fast over a LAN, peers can connect in around 0.5 - 2 seconds max. With PNRP though it sometimes takes up to a minute for peers to connect.
Is this normal? Is something wrong with my setup?
Ages ago I disabled teredo, and that caused PNRP to run very fast. But at the end of the day we will probably need to keep teredo in the mix to help with our application running over a WAN.
Thoughts?
I have used WCF's Peer Channels in an application requiring a Transient Elected Server State. This only needs to work on the LinkLocal cloud, the peers will all be on the same subnet. It does seem to take an inordinate amount of time to register with a cloud, and I am not sure how to confirm if a particular peer is currently registered in a particular cloud (using the abstraction of Peer Channels), but otherwise I like the convenience of it.