Look at this scenario in a massive webserver/application server
The user sends multiple requests that get processed async and call an webservice.
How is the request response cycle?
How does the application server know which packet of response goes to which request?
I know this is a very silly question, however i am not able to find any documentation on how this is handled?
How does the application server track the request and the response?
Related
The concept of Asynchronous Web Service is a web service where the client does not have to wait to receive a response from the server. in AJAX this is implemented by having a callback function to process the response. So the server indeed still sends the response to the client.
Is it possible to have an Asynchronous Web Service without response? Is there any platform that provide this?
Thank you.
I have done asynch web services in the past. They are very useful. YOu do not need a detailed response but you at least need an HTTP response, like 200 OK. If the client that makes the request provides some sort of ID or key for that request, then the client can use the same ID/key to later on query for the result/response of the request.
As far as frameworks that provide this, I do not know of any. In the past I would just have a shared memory store, like Memcache, to store the state and result of the request. As long as the state is shared across all nodes, any node can then process the call back request.
EDIT: Providing a key in the request can be done in either REST or SOAP environment. HTTP provides multiple places where a key can be communicated.
GET query param (REST)
HTTP header (SOAP/REST)
Added to the message body of a POST request. This can be done through two ways.
param in the message body (REST)
variable or attribute in serialized object (SOAP/REST))
I want to send response(I am getting the data from my DB) continuously every 5 minutes without any request from client by using SOAP and Axis2. I have created the SOAP server by using following link. http://www.eclipse.org/webtools/community/tutorials/TopDownAxis2WebService/td_tutorial.html
But I don't know how to response continuously from server. Please help me.
A webservice cannot send a response without being called because it won't know where to send the data nor what function is being invoked (a ws could have many functions).
The idea of a WS is to offer a service to everyone who can access it, so the response destinies are multiple.
If you want to get the data from your DB every 5 minutes, your client will have to call the WS every 5 minutes or less (take into account the server processing time).
I am trying to setup very simple WSO2 ESB Proxy service. While using it, I am getting HTTP 202 response back and WSO2 ESB is not doing anything with the request beside logging it. Here is the background of my setup
My service implementation is using SOAP 1.2 over Http 1.1. When my client opens the connection to the server, it fires first request and asks for keep-alive connection. The ESB passes the request to the actual implementation and sends response back with transfer-encoding as chunked. So far it works as desired.
After the initial request response exchange, my client submits several requests in parallel and I get HTTP 202 responses for all of them. Looking at logs, it seems ESB is not sending the request to the actual implementation ever.
Is there something that I am doing wrong? How do I fix it?
What happens in this scenario is that your subsequent requests are hitting the main sequence of the WSO2 ESB. That is why you can only see a log for those requests. As you have already narrowed down this happens due to the jsessionId attached to the URL. To overcome this issue you can create a REST API with URL pattern to match the correct URL path. Please refer the following documentation.
https://docs.wso2.com/display/ESB481/Creating+APIs
I am trying to send a SOAP request over HTTP for a web service through the following channels:
Telnet (HP-UX)
C client that opens a socket, writes XML and reads reasponse(HP-UX)
Perl client that does the same thing as the C client above(HP-UX)
Through SOAP UI application (http://www.soapui.org/)(Windows Machine)
While SOAP UI gets a response in about 100ms seconds or so; the rest of the channels get the same response but very slow.
I am wondering what might be the problem. If anybody has any idea about this please let me know.
Possibly the connection stays open per default for subsequent requests (not uncommon for webservers which expect you to request all kinds of javascript files, images, css files directly afterwards). You might want to try to send the Connection: close header.
Check the protocol , may be you are using HTTP1.0 not HTTP1.1
I am a new to Axis2 and SOAP. I recently working on a Axis2 SOAP project, I have create a SOAP server and SOAP client by using java and axis2 implementing session scope. The problem is when I send a request, it returns response back only once. I am unable to make web service keep publishing data periodically untill the session end. Can any body help me...
Thanks in advance
I might be wrong, but I think since you work with HTTP you can't make the
response permanent until you make your client perform calls permanently / periodically.
Permanent Requests --> Permanent Responses
I echo KB22's response - HTTP has a request-response flow, so your service is receiving a single request and sending back a single response. Implementing session scope means that you have a logical session for multiple request/responses to be tied together. You have a few options here:
Make the client wait until you have all the data to send back in one response. However, if this takes too long you may well get timeout issues on the client.
Change your model, so that you send in multiple requests and get back the data in pieces.
Change your model to a polling style, where you keep sending requests (and receive empty responses) until all the data is ready to be sent back.
Change your protocol to something that is asynchronous (e.g. JMS) so that you send in a request to a queue and at some later time the response turns up on the queue for your client to read.