There are two kind of messages in Vanet that are considered as safety messages.Their name are
1.beacon
2.event driven (emergency message).
I am using omnet++ 5.4.1,veins 4.7.1 and sumo-0.30.0. However veins just has BSM(beacon) and WSA and data that all of them are not emergency message.how can I access to the emergency message in veins?
I need to access to the event driven message.
I read stackoverflow over and over but I did not find that.
As of Veins 4.7.1, only generic message types are included with Veins. You can use them to create a simulation according to your needs. The tutorial example illustrates how to send an event triggered message with a defined transmit power and access category. It might be a good starting point to write your simulation.
Related
Have an issue with one of MQ queue, where multiple C++ program is trying to access the queue from different host and they receiving 2042 error. I can see they are opening the queue as exclusive INPUT "INPUT(EXCL)" and APPLTAG(mqmessage).
From queue manager side queue is set to shareable and DEFSOPT(SHARED) all looks good.
What are the changes required from C++ program not to open as EXCL input? So that multiple user can access?
Thanks
Openoptions of the C++ application have to be modified.If your c++ application is having "MQOO_INPUT_EXCLUSIVE" as one of the OpenOptions then it has to be removed.
Check this MQOPEN options for removing messages
Following stackoverflow answer is also on the similar lines
IBM WebSphere MQ 2042 error
I am a beginner with XMS and I am having quite a hard time finding a solution to my problem. I hope you will help me find a solution or at least give me a hand.
So, in my project I am using IBM MQ XMS API to send and receive messages. It works well but there is only one problem. When the users send a message that is superior to the Max Msg Length it triggers a general exception. In that exception there is a treament for various case of errors but it lacks the treatments of that particular exception.
What would be the best way to test if the message length is inferior to Max Msg Length defined on the server before sending it? Or at least how should i catch the trigger of that exception more precisely?
(I am sorry I can't post code because it belongs to the company I am working for)
If node crashes and at that point of time messages are queued up in mailbox then how will those messages be reprocessed?
If they can not be reprocessed then how can we say akka programming model is fault tolerant. This is the most basic use case for which we have to use persistent queues right now.
The messages won't be processed and will be lost; Akka does not guarantee message delivery - this is explicitly stated in the beginning of its documentation. However, this does not preclude one to make the program fault-tolerant. One of the simplest ways to do so would be to implement messages with acknowledgements and make actors re-send messages which were not acknowledged.
Entire typesafe stack is built around microservices.. If you have doubt then read their presentations.. Akka streams Alla HTTP they all are in this direction... Seems your view of Microservice is different from mine... Despite that you missed the main point.. Distributed fault tolerant architecture problem was supposed to be solved by Akka.. If you are using rabbitmq then you are not going to get all benefits of akka.. Like location transparency.. Actor heiraarchy..do post your architecture diagram to Akka forums and see what response you get
We're currently updating from Akka 2.0.4 to 2.4.2 (I know, quite a big leap, but nobody thought to do it incrementally).
Anyway, in the old codebase, our master node is connected to some remote slave nodes that sometimes fail (the "why" is still to be investigated). When a slave dies, the master receives a RemoteClientShutdown event from which we can extract the getRemoteAddress and process it accordingly (e.g. inform the admin per email pointing to the failed node address).
In version 2.4.2 the RemoteClientShutdown class is replaced (at least I suppose so) by RemotingShutdownEvent which, being an object, doesn't carry any specific information as to the source of the event.
I've checked the migration guides as well as the current documentation but couldn't find info on how to solve this problem. According to the Event Bus documentation, the only way to extract such information is by providing it in the message ("Please note that the EventBus does not preserve the sender of the published messages. If you need a reference to the original sender you have to provide it inside the message").
Should I somehow override the message sent on the remote system shutdown? Or is there any other recommended way to solve it? I hope this question is not too newbie, I'm still quite new to Akka.
Ok, solved it using DisassociatedEvent which actually contains the address and other useful information. Turns out I was misled by the name of RemotingShutdownEvent which is actually received "when the remoting subsystem has been shut down" (docs) and not when a remote actor has been shut down.
I am new to creating Windows applications in C++. My task is to write two cpp files, one of which will send a number (x) to the other one, the other one will evaluate f(x) and send it back to the first one. I should implement it using Messages. Couldn't get anything specific online, Could someone pls give me a clue, where to start?
Great thanx!
Are you talking about window messages? If so, the sending app could use SendMessage, which would cause the receiving app to get its window procedure executed. Of course, this means that the receiving app needs to create a window whose window handle is somehow made available to the sending app.
You can do it in several ways.
Using WM_COPYDATA message to pass the data
Allocating global memory to pass data and sending your own message, such that second program can read the data from memory
Sending a message (if two ints suit your needs to pass data)
Using named pipes
Using TCP/IP local connection (peer to peer or through a server)
Look at ZeroMQ (http://zeromq.org ; cross-platform, LGPL). It is a very simple, lightweight and powerfull library. From the very basic level you can use it to exchange UDP-style datagrams, but through reliable transport (TCP or some variants). Also you have cancelling support, time-based polling and advanced network schemes (which are non-needed in your case). I've selected it for a similar task, and it performs very well.