I have a little problem with RPC communication. It works really well without VLANs, but when I add Vlans and configure network with them. I can only connect to the device from a python script, but all RPC communication gives me a timeout error. If the network is only on Unit 0 RPC messages work fine. I work on GNS3 environment, 2 times vSRX 19.2R1.8 One as Firewall, the other in Switch mode.
Could it be a configuration problem?
I can also send configuration of devices
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I have an app which creates two instances of RTCPeerConnection (within the same JS context) which attempt to connect to each other. While I'm developing, I reload the page often, maybe several times per minute. About 10% of the time, WebRTC will fail to progress to the 'iceConnectionState == "connected"' stage. This failure occurs even when I pass no STUN/TURN servers to createPeer().
I primarily use Chrome (OSX, currently version 81.0.4044.138). I have never been able to reproduce this on Firefox.
I have captured nearly-identical dumps of the success and failure cases using chrome://webrtc-internals.
I have spent many hours on this and haven't found any clue as to why this might be failing. Is it just some kind of temporary local network outage? Is there anything I can do within the code to have a 100% local connection rate?
I have seen similar flakiness because of mDNS candidates. Try disabling #enable-webrtc-hide-local-ips-with-mdns in chrome://flags and see if that helps!
After that I would grab a tcpdump and confirm you see ICE traffic flowing each way.
I wish to run an experiment in which the publisher loses connection with the broker and then enqueues messages in its own queue and then when it regains connectivity it sends all its queued messages to the broker. How can I I do this since if I call close connection, I can no longer send(raises an exception). A trick that I can think of is to use a network of two brokers and simulate the above by breaking the connection between the two brokers. Is there an API call that I can use to do the above?
This is very much like facebook messenger or whatsapp acting as a publisher and enqueuing our to-send messages if we are offline and sending them once we are connected.
There is plenty of solutions you could use to break the connection in order to test, here is a non-comprehensive list :
Make a script that can set/unset a firewall rule on your environement blocking the connection port
If you are working with VMs, you can suspend/resume the one running Activemq, you can even automate it with tools like vagrant (vagrant suspend, then vagrant up)
Tweak the connection manualy accessing the activemq jmx
Develop an activemq plugin able to trash connections on demand (or maybe there is one ?)
Now in order to have the behavior you wish to obtain there is two options :
1) Make sure your connection is failover so it can be reestablished, and store your message on disk before sending them with your producer.
2)Produce to a local broker embbeded in your app, and connect this one to the remote broker.
I am not pasting the source code here, if any one whats to reproduce the problem, download the code from this github project:
It is a Comet server, the server use libevent-2.0.21-stable http.
To reproduce the problem:
start the icomet-server from machine S
run curl http://ip:8100/stream from another machine C, the server S will show message that C has connected
if I press CTRL + C to terminate curl, the server knows that C is disconnected as expected.
if I pull out the network line from machine C(a physical network broken), the server will NOT know that C is disconnected, which it SHOULD know!
I will askany one who is familiar with libevent, how to make libevent 2 to detecting client network broken?
When the physical network link is interrupted, you won't always get a packet back to tell you that you lost the connection. If you want to find out about a disconnection, send a ping (a request that just asks for a no-op reply) periodically, and if the reply doesn't come within some reasonable timeout, assume something went wrong. Or just disconnect the client if they're idle for long enough.
When you did that Ctrl-C, the OS that the other end was running on was still working, and so it was able to generate a TCP RST packet to inform your server that the client has gone away. But when you break that physical link, the client is no longer capable of sending that cry for help. Something else has to infer that the client went away.
Now, if you try to send the client some data, the server kernel will notice (sooner or later) that the client is not replying to its messages. At this point you'll see the disconnect - but it may take several minutes for this to happen. If you're not sending any data, then it'll stay open until either you disconnect it, or the kernel attempts a TCP keepalive (a low-level way of the kernel asking "Hey, I haven't heard from you for a while, are you still there?") potentially hours later (or it might not even do a keepalive at all for you, depending on how things are configured).
I'm writing an application which will use the Azure Service Bus. For local development I'm using Windows Server Service Bus to provide the same services (the code to use either is identical).
I want to write the application to be tolerant of transient errors when sending or receiving messages. To that end, I want to be able to test the fault-handling code can deal with the local Service Bus instance suddenly being unavailable during execution of various operations.
Ideally, I'd want to write some automated integration tests around these scenarios, but I appreciate that may not be practically achieved.
What can I do to simulate transient errors on my local Service Bus?
One easy thing would be to call the stop-sbservice (affects one node) or stop-sbfarm (affects the entire farm) cmdlets. This would let you simulate a servicebus outage locally. You can then call start-sbservice or start-sbfarm to bring the service back and validate that your code recovers properly. This approach also has the added benefit that you control when the service returns (compare to just crashing the process). This page has information on the available cmdlets.
If that's not enough, another approach that I've used in the past is to shut down the network interface, or, if the server is in another machine, put up a firewall on the ports used to communicate to service bus.
consider a WCF service, which is heavily used and behaves normally. But then is stopps responding. In the sevice level message trace you can see the outgoing message on the client, but no incoming message on the server. On transport level theres a incoming message and then nothing. After 60 seconds the client throws a TimeoutException.
What can cause a behavior like this?
What would you do to debug this behavior?
Is it possible that this behavior is caused by too many concurrent connections/sessions?
EDIT:
Client and Server are on the same machine. Both are .NET apps. When the client is restarted the problem sometimes does not happen. Also the problem does only appear on a single machine. I was not able to reproduce the behavior on any other machine.
Regards
Michael
I understand you have no problem on network level as you have mentioned that you can see incoming request on transport level.
So the first thing to check does the service is up and does it works if the client is on the same machine.
Also you can analyze incoming messages may be the problem can be there.
Here WireShark will be your friend.
Also check can you view the wsdl from the client machine. By the way are your clients also .NET apps?
You can configure tracing using the application’s configuration file—either Web.config for Web-hosted applications, or Appname.config for self-hosted applications by Service Trace Viewer
or use from debug tools such Debug Diag