How to get response time with RestEasy client - jax-rs

I'm using a ResteasyClientBuilder to build an Http Client and I would like to log the response time of each request.
I tried using Request/Response filters to measure the time, problem is that I'm building the client with connectionPoolSize(1) and have multiple Threads using the client concurrently, so the time measured by the filters includes the time waiting for the connection to be free.
How can I get the pure request response time?

Related

Does JMeter have Request Time vs Response Time graph?

I need to know exact response time for particular request sent. Is there any plugins similar to my requirement where i can see both the request and response time together.
From my research, Response Time vs Thread was similar to my requirement but can we consider number of threads as number of request in JMeter ?
There is no such a thing that "request time", JMeter measures:
request start time
response time which also includes
connect time
and latency
The closest thing is Transaction Throughput vs Threads chart which is available as a part of KPI vs KPI Graphs bundle, can be installed using JMeter Plugins Manager

ASP.NET Core and 102 status code implementation

I have long operation, which called via Web API. Status code 102 says to us:
An interim response used to inform the client that the server has
accepted the complete request, but has not yet completed it.
This status code SHOULD only be sent when the server has a reasonable
expectation that the request will take significant time to complete.
As guidance, if a method is taking longer than 20 seconds (a
reasonable, but arbitrary value) to process the server SHOULD return a
102 (Processing) response. The server MUST send a final response after
the request has been completed.
So, I want to return 102 status code to client, then client waits response about result of operation. How to implement it on .NET?
I read this thread: How To Return Http 102 Processing in Asp.Net Web Api?
This thread has good explanation what is necessary, but no response. I don't understand how it implement on .NET, not theory...
Using HTTP 102 requires that the server send two responses for one request. ASP.NET (Core or not) does not support sending a response to the client without completely ending the request. Any attempt to send two responses will end up in throwing an exception and just not working. (I tried a couple different ways)
There's a good discussion here about how it's not actually in the HTTP spec, so implementing it isn't really required.
There are a couple alternatives I can think of:
Use web sockets (a persistent connection that allows data to be sent back and forth), like with SignalR, for example.
If your request takes a long time because it's getting data from elsewhere, you can try pulling in that data via a stream and send it to the client via a stream. That will send the data as it's coming in, rather than loading it all into memory first before sending it. Here's an example of streaming data from a database to the response: https://stackoverflow.com/a/45682190/1202807

Can RabbitMQ (or similar message queuing system) be used to single thread requests per user?

The issue is we have some modern web applications that are integrated with a legacy system that was never designed to support multiple concurrent requests from a single user. Basically there are certain types of requests that the legacy system can only handle one-at-a-time from a single user. It can handle multiple concurrent requests coming from different users, but for technical reasons cannot handle multiple from a single user. In these situations, the user's first request will complete successfully, but any subsequent requests from that same user that come in while the first request is still executing will fail.
Because our apps are ajax enabled, multi-tab/multi-browser friendly, and just the fact that there are multiple apps - there are certain scenarios where a user could wind up having more than one of these types of requests being sent to the legacy system at the same time.
I'm trying to determine if something like RabbitMQ could be positioned in front of the legacy system and leveraged to single-thread requests per user/IP. The thinking being that the web apps would send all requests to MQ, and they'd stack into per-user queues and pass on to the legacy system one at a time.
I don't know if there would be concerns about the potential number of queues this could create - we have a user-base of approx 4,000.
And I know we could somewhat address this in the web apps individually, but since there are multiple apps it'd be duplicating logic across them, and you'd still have the potential for two different apps to fire off concurrent requests.
Any feedback would be appreciated. Thanks-
I'm not sure a unique queue per user will work as you would need to have a backend worker process listening for messages on that queue that would need to be dynamically created.
Below is one option but it does have a performance bottleneck potential as a single backend process would be handling all requests sequentially. You could use multiple worker processes but you wouldn't know if one had completed before the other causing a race condition if your app requires a specific sequence of actions.
You could simply put all transactions (from all users) into a single queue and have a backend process pull off of that queue and service the request. If there needs to be a response back to the user once the request was serviced, then the worker process could respond back to a separate queue with a correlationID that could be used to send the response date back to the correct user.
I've done this before with ExpressJS apps where the following flow would happen:
The user/process/ajax makes a request
Express takes the payload from the request object and sends it to a RabbitMQ queue with a unique correlationId (e.g. UUID).
Express then takes the response object and stores it in a responseStore object with the key being the correlationId
Meanwhile, a backend worker process pulls the item from the queue, does some work and then sends a message to a different response queue with the same correlationId
The ExpressJS application has a connection to the response queue and when it receives a message, it takes the correlationId from the response and looks for a response object stored with same correlationId in the responseStore. If it finds it, it takes the payload from the message and does something like response.send(payload) or response.json(payload)
To do this, you should also have a mechanism that stores the creation time of the response object in the responseStore along with the response object. Then have a separate process that will check the responseStore and clean up old response objects after a certain timeout in case there are issues with the backend process completing.
Look here for more info on RPC with RabbitMQ:
https://www.rabbitmq.com/tutorials/tutorial-six-javascript.html
Hope this helps.

Is there a way to add header to apache response on how long it took to retrieve a resource?

Is there a module or a built-in function in apache which I can use/activate to send information how long it took to retrieve/process a resource?
For example the resource http://dom.net/resource is accessed. The response header will include the total time it took to wait for the resource to be ready before it gets sent back to the client.
Apache doesn't really 'wait' until the resource is ready before sending the response back to you - it streams data back to the client as and when it receives it.
Depending on what you're interested in measuring, you could record the time taken for the client to receive the first byte/last byte back from Apache, or measure the time taken for Apache to receive the first byte from the (remote?) resource like so. The time taken for Apache to receive the entire response back from the remote resource is not something you can send in the headers, as the headers will have been sent to the client before the remote response is fully received. This information could trivially be written to the Apache logs, however.

Understanding fiddler statistics

We are sending a HTTP WCF request to a 3rd party system hosted on our servers and were experiencing a significant delay between sending the request and getting the response. The 3rd party are claiming that they complete their work in a few seconds but in fiddler I can see a significant gap between the ServerBeginResponse and the GotResponseHeaders.
Now I'm not sure what could account for this delay? Could someone explain what the ServerBeginResponseand the GotResponseHeaders timers in Fiddler actually mean?
The timers mean pretty much exactly what they say-- The ServerGotRequest timer is set when Fiddler is done transmitting the HTTP request to the server. The GotResponseHeaders timer is set when Fiddler has read the complete set of response headers from the server.
In your screenshot, there's a huge delay between ServerBeginResponse (which is set when the first byte of the server's response is returned) and GotResponseHeaders which suggests that the server spent a significant amount of time in completing the return of the HTTP response headers.
If you send me (via Help > Send Feedback) a SAZ capture of this traffic, I can take a closer look at it.