I've made some performance improvements to my application's backend, and to show the benefit to the end users of the GUI, we've been using the Trace.axd page to take timings. (The frontend is .Net 1.1 and the backend is Java, connected via Web services.)
However, these timings show no difference between the old and the new backends.
By putting a breakpoint in the backend and holding a request there for 30 seconds, I can see from Trace.axd that the POST is taking 3ms, and the GET is taking 4s. I'm missing about 26s...
The POST is where the performance improvement should be, but the timing on the Trace page seems to only include the time it takes to send the request, not the time it takes to return.
Is there a way to inrease the granularity of the information in the trace to include the whole of the request? Or is there another way to take the measurements I need?
OK, I kind of got what I wanted in the end. The problem is the IIS Trace doesn't include the time the POST takes to return.
I found that I could use Trace.Write() to add custom entries to the trace log, and even add a category, using Trace.Write(string category, string message).
Adding a call to Trace.Write() in my code that executes after the POST has completed gives me a better figure.
Still, it's not ideal as it's custom, and it's down to me to put it as near to the end of the POST cycle as possible.
I'm not sure how you're making the requests on the .NET side, but I'll assume that there's a HttpWebRequest involved somewhere. I'd expect HttpWebRequest.GetResponse() to return as soon as it has received the response headers. That way, you can start processing the start of a large response while the rest is still downloading. If your trace messages are immediately before and after a call to GetResponse, you therefore wouldn't see the whole execution time of the backend. Can you add a trace message immediately after you close the response?
It is abnormal that the trace output doesn't show all the time you've spent in the brakpoint. Did you check the total time column to see if it matches the time you've spent in the request ? Don't forget that one of the columns only shows the time spent since the preceeding trace statement.
If you want more granular data in the trace output, you can add your own. The TraceContext class has two methods, Warn and Write that add lines to the output (warn adds it in red).
The TraceContext is accessible from every page or control: just use this.Trace.Warn() or this.Trace.Write() (and I think it is also accessible through the HttpContext class).
Related
How GET method is idempotent and POST is not. we are using it in form submission, if we submitting it twice it will re-submitting the form data's. And why we are not using GET for order placing or purchasing products for instance when it is idempotent.
An idempotent HTTP method is a HTTP method that can be called many times without different outcomes. It would not matter if the method is called only once, or ten times over. The result should be the same. Again, this only applies to the result, not the resource itself.
a=10; //This is idempotent: no matter how many times we execute this statement, a will always be 4.
a++; //This is not idempotent. Executing this 10 times will result in a different outcome as when running 5 times.
Now, coming to your query.
If we use GET method for order placing/purchasing products, the order will be placed no matter the product is gone out of stock. In contrast if you use the to POST method the result will be different for each new request made for purchasing product.
Below example is not idempotent because for every new request the outcome will be different
https://accounts.google.com/Login#identifier
The GET method should be used to send the information from the browser to the server in the URL. Below is an example usage of GET method.
http://www.google.co.in/search?q=cristiano+ronaldo
Below is the answer to your query in the comments:
When users revisit a page that resulted from a form submission, they might be presented with the page from their history stack (which they had probably intended), or they might be told that the page has now expired. Typical user response to the latter is to hit Reload.
This is harmless if the request is idempotent, which the form author signals to the browser by specifying the GET method.
Browsers typically will (indeed "should") caution their users if they are about to resubmit a POST request, in the belief that this is going to cause a further "permanent change in the state of the universe", e.g. ordering another Mercedes-Benz against their credit card or whatever. If users get so accustomed to this happening when they try to reload a harmless idempotent request, then sooner or later it's going to bite them when they casually [OK] the request.
Now, while implementing those two methods GET and POST, a developer should consider the security issues and write the code in the particular method. Any code can be written in both the methods considering all the limits of GET method(size of url etc.), But this is not a good practice.
GET -> for information retrieval.(If you want to read data without changing state)
POST -> for information creation/updation/deletion.
I have a set of requests I run together in a group. One of them starts some async operations on the server. I need to insert a n-second pause between this request and the next to give those async operations time to complete. How can I do this?
Unfortunately it isn't possible yet with Paw. Though we're going to bring a nice testing flow (with assertions, request flow, waits, etc.) in a future release.
As a temporary workaround, you could add a dummy request to a "sleep" page alike: http://httpbin.org/delay/3
A screenshot to explain this better (and a video here to see it run):
Given the chart here, what should I be looking at to identify the bottleneck? As you can see, requests are averaging nearly 14 seconds under load and the bulk of that time is attributed to the CLR in New Relic's profiling data. In the performance breakdown for a particular page, it attributes the bulk of the time to the WebTransaction/.aspx page.
I see that the database is readed also (the orange) and this is seams that one of all pages have delay the rest of pages because of the lock that session make on the pages.
you can read also :
Replacing ASP.Net's session entirely
My suggestion is totally remove the session calls and if this is not possible, find an other way to save them somewhere in database by your self.
Actually in my pages I have made all three possible options. 1. I call the page with out session. 2 I have made totally custom session that are values connected to the user cookie, and last 3. I have made threads that are run away from the session and they make calculations on background, when they finish I show the results.
In some cases the calculations are done on iframe that call a page without session and there later I show the results.
In the Pro version, you can use Transaction Traces, which help pinpoint exactly where the issue is happening.
I've got a site that uses an order entry form and sends a rather decently sized POST request when the form is submitted.
However, when a particular value is passed in one of our form variables (OrderDetail), every time without fail, it gets an error page in the browser and a 504 error via Fiddler.
Here are a couple examples of tests I ran last night sending POST requests through Fiddler. When the "OrderDetail=" value is changed to the below it will either submit successfully or return a 504 error after a few seconds:
These ones FAIL:
&OrderDetail=Deliver+Writ+of+Execution%3B+and+Application+for+Earnings+Withholding+Order+to+Los+Angeles+County+Sheriff+DASH+Court+Services+Division+per+instructions
&OrderDetail=Deliver+Execution+Earnings+Withholding+Order+to+Los+Angeles+County+Sheriff+DASH+Court+Services+Division+per+instructions
&OrderDetail=Deliver+Writ+of+Execution%3B+and+Application+for+Earnings+Withholding+Order+to+Los+Angeles+County+Sheriff
&OrderDetail=Deliver+Writ+of+Execution%3B+Application+for+Earnings+Withholding+Order+to+Los+Angeles+County+Sheriff
&OrderDetail=Writ+of+Withholding+Execution+Order+Los+Angeles+County+Sheriff
&OrderDetail=writ+Execution+adsfsdfsdfsd+Order+County
&OrderDetail=wd+Execution+adsfsdfsdfsd+Order+Count
This got me thinking that perhaps it has to do with the words "Exec" ('Exec' and 'Execution' throw errors, 'Exe' does not) and "Count" ('County' and 'Count' throw errors, 'Cont' does not)
However, I haven't seen anything this specific mentioned in google searches regarding the 504 error.
Regarding the Coldfusion code around this, there is nothing fancy for this page. Just a standard form post. I added a cfmail test in the Application file and on these failures it is never ran, so this seems to be between the browser and IIS. We're on a shared server, so I can't see too much there, though.
Oddly enough, when the &OrderDetail= param is changed to one of these values (very similar to the above), the result is success:
&OrderDetail=wd+Execution+adsfsdfsdfsd+Order+Coun
&OrderDetail=wd+Execution+adsfsdfsdfsd+Order+Conty
&OrderDetail=Writ+of+Withholding+Order+Execution+Los+Angeles+County+Sheriff
&OrderDetail=Writ+of+Withholding+ExecutionOrder+Los+Angeles+County+Sheriff
In the 3rd one, I put 'Order' BEFORE 'Execution' and it works..
The total length of this POST request is about 4720 characters. I've increased the length of this one field to 5-6 times its length and they passed, so it almost seems tied to the value of the "&OrderDetail" param in the POST.
Any ideas on why this specific data could be an issue for a web server? I've never seen this before and it doesn't continue to be a problem for nearly any other request going through.
One interesting note as well: In the POST request, this variable is pretty close to the start of the param list. If I delete everything after it, it goes with no problem. Although I haven't been able to nail down what in the subsequent lines could be causing it. I can post the entire request if it will help.
More importantly though, I just want to know what could qualify as "reserved" or "illegal" for FORM data. Everything appears to be escaped properly so I'm not sure what else can be done here except for some pre-processing javascript to further escape any such words.
Thanks!
Given that EXEC and COUNT are causing the error, whilst putting ORDER before EXEC is preventing the error, this sounds like something is making a flawed attempt at protecting from SQL injection attacks.
If you have any software in place that claims to do that, I would see if (temporarily) disabling it stops the problem from occurring.
(This software might be at the firewall level, so you may need to talk to your sys admins.)
Importantly, I would also check your codebase for where OrderDetail is used, and make sure that it is using cfqueryparam whenever it is used inside a query - and the same goes for all other user-supplied data.
I have an application variable which is populated onstart (in this case it is an array). Ideally I need to rebuild this array every 3 hours, what is the best way of going about this?
Thanks, R.
Save the time you last refreshed the variable contents.
On every request, check the current time against the saved time. If there's a three hour difference, lock and refresh the variable.
As long as there are no requests, the variable also needs no refreshing.
If your application variable must remain "in process" with the rest of the site's code, the way suggested by Tomalak may be your only way of achieving this.
However, if it's possible that the application variable could effectively reside "out of process" of the website's ASP code (although still accessible by it), you may be able to utilise a different (and perhaps slightly better) approach.
Please see "ASP 101: Getting Scripts to Run on a Schedule" for the details.
Tomalak's method is effectively Method 1 in the article, whilst Method's 2 & 3 offer different ways of achieving what is effectively something happening on a schedule, and avoid the potentially redundant checking with every HTTP request.