Thingsboard - RPC - Knob - Request Timeout - request

I've been trying to get the Knob Widget to send data to a temperature meter in my Thingsboard Dashboard but all i get is "Request Timeout" and no data to the temperature meter. Is there someone who have succeeded with this before?
Thanks.

I succeeded with this before. Find more infos in the documentation:
https://thingsboard.io/docs/user-guide/rule-engine-2-0/tutorials/rpc-request-tutorial/
You have to prepare the device in order to subscribe to the RPC messages from the ThingsBoard Server (e.g. via MQTT):
https://thingsboard.io/docs/user-guide/rpc/#processing-server-side-rpc-on-the-device
This could be missing in your case, resulting with "Request Timeout.

Related

Logic app executed twice for the same message from servicebus queue with message state=Active and Scheduled

A message is being dropped to Service bus queue with ScheduledEnqueueTimeUTC and Service Bus Connector in Logic app has trigger set to pick messages from queue at 12:05AM EST EveryDay.
Problem: Logic app has picked the same message twice one with Service bus message properties State='Scheduled' and other with state='Active' with same sequenceNumber. May i know when this happens and how can this be solved.
Problem: Logic app has picked the same message twice one with Service
bus message properties State='Scheduled' and other with state='Active'
with same sequenceNumber. May i know when this happens and how can
this be solved.
Here we discovered one of the workarounds that will meet your needs. To pick and send a message only once, we must set our settings to split on as seen below.
NOTE: I tried using Logic app standard, as this option is not available in Consumption plan
Please refer this MS DOC & SO THREAD for more information .

AngularJS 1: How not to "Socket hang up" on a request which is taking long time to respond

I am sending a request from client(angularjs) to backend requesting 1million records. I know this is dumb but that's the requirement. The request will run a stored procedure in Oracle database which is taking around 3 minutes and within this time, at the client side, am getting the error "problem with request: socket hang up" and the request is failed.
Can anyone please let me know how to increase this time taken for socket to hangup ? or any other solution is also welcome
Thanks in advance.

Salesforce Outbound Messages

I used postbin.org to test the workflow outbound message service. I specified the criteria like Account Name not equal to Null.But when I create record of Account Object,I am getting
org.xml.sax.SAXParseException: Content is not allowed in prolog. error in Delivery Failure Reason.
I dont know to to check it out.Please let me know.Thanks in advance..
The Outbound messaging feature requires that your listener send back a well formed soap message indicating that it successfully processed the message as its HTTP response. It seems unlikely that postbin.org is sending that response, and hence OM is reporting that as a delivery failure, and the message will get retried again later.

is it possible to send a not requested info or command to clients in silverlight?

in a Silverlight application, we used to send requests from client to server and receive its response.
is it possible to send an information from server to client which is not waiting for? for example server ask client to update a text in a special text box and so on. "an info or known command which may come to client any time and is not a response to the client's request"?
You can use Duplex Services for this.

How to achieve interrupt-driven communication from server to client with servlets?

we wrote in C++ a screen sharing application based on sending screenshots.
It works by establishing a TCP connection btw the server and client, where the server forwards every new screenshot received for a user through the connection, and this is popped-up by the client.
Now, we are trying to host this on google app engine, and therefore need 'servlet'-ize and 'sandbox' the server code, so to implement this forwarding through HTTP requests.
I immagine the following:
1. Post request with the screenshot as multiple-data form (apache uploads ..).
But now the server needs to contact the specified client (who is logged in) to send it/forward the screenshot.
I'm not sure how to 'initiate' such connection from the servlet to the client. The client doesn't run any servlet environment (of course).
I know HTTP 1.1 mantains a TCP connection, but it seems gapps won't let me use it.
1 approaches that comes to mind is to send a CONTINUE 100 to every logged in user at login, and respond with the screenshot once it arrives. Upon receival the client makes another request, and so on.
an alternative (insipired from setting the refresh header for a browser) would be to have the app pool on a regular basis (every 5 secs).
You're not going to be able to do this effectively on GAE.
Problem 1: All output is buffered until your handler returns.
Problem 2: Quotas & Limits:
Some features impose limits unrelated
to quotas to protect the stability of
the system. For example, when an
application is called to serve a web
request, it must issue a response
within 30 seconds. If the application
takes too long, the process is
terminated and the server returns an
error code to the user. The request
timeout is dynamic, and may be
shortened if a request handler reaches
its timeout frequently to conserve
resources.
Comet support is on the product roadmap, but to me your app still seems like a poor fit for a GAE application.
Long Polling is the concept used for such asynchronous communications between server and client.
In Long Polling, servlet keeps a map of client and associated messages. Key of Map being client id and value being list of messages to be sent to the client. When a client opens a connection with server (sends request to a servlet), the servlet checks the Map if there are any messages to be sent to it. If found, it sends the messages to the client exits from the method. On receiving messages, the client opens a new connection to the server. If the servlet does not find any messages for given client, it waits till the Map gets updated with messages for given client.
This is a late reply, I'm aware, but I believe that Google have an answer for this requirement: the Channel API.

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