While building this web service and the app that calls it, we have noticed that the first call to the web service each day is extremely slow. It even will time out on some days. However, every call after that work great. Can anybody shed light on why this might be and how we can get rid of this pain?
Thanks in advance!
If it's an ASP.NET web service, it may be the CLR initializing and loading and verifying the assemblies for the first time. You may want to consider pre-compilation
Agree with the other answers on caching, initialization, etc. As far as a workaround, one possibility may be to set up some sort of daily task (SQL Server job, Windows service, something else?) to simulate a hit to the service each day, so that your users don't experience this first slow request.
If it is an ASP.NET web service, then you might want to check the settings of the application pool the web service is running in, especially the idle timeout which defaults to 20 minutes in IIS7.
Configuring IIS7 idle-timeout
Even if it is not an ASP.NET web service, other web servers will have equivalent configuration settings you have to tweak to keep your web service alive overnight.
Can you duplicate the same behavior on your database? It could just be the db needing to optimise the query for the first run (Maybe the parameter is today's date?).
Are there a lot of static constructors or set up code in the Global.asax class? Because IIS recycles worker processes periodically, the start up code may be running again.
The rule for optimization is: don't guess. Put in profiling to find out exactly what is slow, and then work to make that faster. Everything already posted provides excellent tips on where to start looking for slowness.
Related
UPDATE
It appears this issue is caused by a bug related specifically to using Axis2 with ColdFusion and we have been able
to replicate the issue in our production environment on two different servers by
switching between Axis1 and Axis2. My original tests to compare the
two were apparently thwarted by an override in an Application.cfc
which forced Axis2.
We ran into a memory leak today which forced us to speed up the resolution to this issue. It resembled the leak
discussed here though we aren't sure if it is the exact same
problem
(https://www.hass.de/content/coldfusion-10-webservice-leaking-memory-trusted-cache-leaks-memory).
Our primary webservices are in Axis1 and we only switched to Axis2 for
this new set of webservices because we needed document literal style
for SalesForce and with Axis1 an invalid wsdl was being created (did
not properly describe all object types in arrays). So now we have it as
Axis1 and using a manually manipulated wsdl. Not entirely sure if it
will work out with SalesForce but as far as a general fix this works.
I am investigating an issue with our coldfusion based soap webservices in our production environment. It appears that the time between the return statement in the webservices method code and actually receiving a response can be significant and appears to directly correspond to the size of the response and/or number of objects.
In development a particular request that returns 1000 records takes about 6 seconds to return. However in production that same hit takes 50+ seconds to return. I added some timing code and found that the actual function code takes less than 1 second to run at the start of the request, meaning that generating the response is taking coldfusion about 50 seconds in production. Hitting the webservice with simple http request does not have the same slowness so seems to be soap/axis specific. The resulting xml is about 1MB which I have compared and found no differences. I also copied out settings from cfadmin in both environments to compare and could find no performance related setting differences.
Both environments are at the same CF 10 update level. The server monitor shows no significant memory usage. I also ran the request from in the server to make sure there wasn't some slow connection issues or https slowing things down but the results are the same.
Any suggestions or solution would be appreciated.
Additional notes...
CPU sits at about 17% for most of the time of the request which is a lot of work to be doing. Something is happening very inefficiently
I tried switching instance to Axis1 and back again followed by an instance restart and additional tests with no change in results
One possibility is that you have them throttled - check the "request tuning" in your CF administrator. By default the setting for "number of simultaneous web service requests" is 10. Are you looping and hitting the server? In production is there more traffic?
In server monitor enable profiling and monitoring, then click on "statistics". On the far right there is a little chart icon. click on it and you will see a chart and a counter legend in the top right. Then run your code. Does the "web services running" reach a threshold and cross into "web services queued" - if so you need to increase that threshold.
One more clue - in the server monitor do NOT run the "memory profiling for more than a few seconds - say 30. If you don't you will have performance problems for sure.
I have an Apache2 and Django (mod_wsgi) setup that provides a RESTful API. I have a set of automated tests for this, that executes ~1000 API requests (pure http GET/POST/PUT/DELETE) in sequential order.
The problem is, for every 80 requests or so, I get a strange lag/timeout for exactly 5s or 10s. See timestamp examples here:
Request 1: 2013-08-30T03:49:20.915
Response 1: 2013-08-30T03:49:30.940
Request 2: 2013-08-30T03:50:32.559
Response 2: 2013-08-30T03:50:37.597
I can't figure out why this happens. I have an apache config with KeepAlive Off (recommended setup setting for Django) but otherwise standard install for Ubuntu 12.04 LTS.
I'm running the tests from the same server where the webserver is, I first thought this was some kind of DNS cache thing, but I've added the hostname I'm requesting to /etc/hosts but the problem persists.
The system is idle and have lots of cpu and mem when this lag/timeouts happens.
The lag is not specific to a certain request (URL), it seems kinda random.
Considering that it's always exactly to the millisecond 5s or 10s, it feels like this is some specific setting somewhere causing this.
In case it provides some insight, watch my talk from PyCon US.
http://lanyrd.com/2013/pycon/scdyzk/
The talk deals with things like process churn and startup costs. One thing you shouldn't do is set maximum requests if you don't really need it.
Also consider trying New Relic to help diagnose where the issue is. That will save a lot of guessing if it is a web application of backend service infrastructure issue.
As far as seeing how such monitoring can help, watch another one of my PyCon talks.
http://lanyrd.com/2012/pycon/spcdg/
This was a DNS issue, adding the domainname I used locally to /etc/hosts actually solved the problem. I just hadn't reboot the server for the changes to take effect, thought restarting networking would take care of that, but apparently not.
I have a mobile application integrated to a server where users can see tasks assigned and close the task request after work. In this project timing is very important, at least ones in a minute program should check if a task is assigned. Moreover mobile should also check the server if there is a change on the task that it already downloaded.
Because of the nature of the project download amount is high. How can we reduce it? Should we use another technology for server communication (Now we use ASP.NET Web Service Application)?
Thanks in advance.
Use JSON instead of XML Server.
Try using selective sync options like instead of complete tasks sync as it would become slow with higher number of tasks.
Mark task changes locally on mobile. mark entities dirty and then only update marked tasks to cloud/Server.
as SLaks suggested use push instead of pull it will save mobile battery and user's data package.
Here is what can help you:
Microsoft Sync Framework.
http://msdn.microsoft.com/en-us/sync/bb887608.aspx
http://weblogs.aspnet05.orcsweb.com/sbehera/archive/2009/04/10/sync-framework-for-windows-mobile-devices-amp-some-use-full-links.aspx
I am writing an ASP.NET web page which calls an API to update my client's property website using XML data. The data from the API is real-time, so I would like to run the page every 10 minutes.
Clearly I don't want to load my page manually to keep my client's property website up-to-date. There is a lot of help in Stack Overflow and elsewhere on this type of question but I have become a little overwhelmed by the options. I think that one way to go would be:
Windows Task Scheduler to fire every ten minutes (to trigger a VB.Net Service)
VB.Net Service (to run the web page)
My page runs..
That feels like overkill, and I haven't written a Windows Service or used the Task Scheduler and it feels like there should be 2 steps not three.
Now if I do use a VB.Net Service then I think that it might be better to give more work to the VB.Net Service rather than put my script in a web page, but I am used to writing web pages!
I can't help feeling that if I just keep the page open in a browser somewhere I can easily use JavaScript to run the page every 10 minutes, but that means ensuring it's open in a browser. Bad solution I think...
What I need is an overview of my options to make an informed decision and if it means learning then fine. Thanks in advance!
You can use javascript/Jquery to call a page/webmethod continously in timely manner
setInterval(function() {
// call your page or webmethod
}, 1000 * 60 * x); // x is your time interval in mins, in your case x=10
In my opinion the best approach would be to create a windows service and have the service call the web page. The windows service is much more stable than the Task Scheduler because the task scheduler can overlap if the previous Scheduled event did not finish. Also using the windows service gives you more control over error handling and logging
Get started with this link:
http://code.msdn.microsoft.com/windowsdesktop/CSWindowsService-9f2f568e
I've started using SOAP UI recently to test web services and it's pretty cool, but it's a huge resource hog.
Is there any way to reduce the amount of resources it uses?
It shouldn't be a resource hog, although I've seen it do this before. I leave it running on my PC all week, and a co-worker with a similar machine (dual-core running XP) has to kill it every few hours, otherwise it keeps using CPU. I'd try uninstalling/re-installing. Currently, my instance has been up for 10 days, running a mockservice that I've been hitting very hard (I've sent it thousands of requests). CPU time total (over 10 days) is about an hour and a half, but the "right now" number is about 1%.
There are no popular alternatives, aside from writing your own client in the language of your choice.
If you're testing WCF services, you can run wcftestclient from the Visual Studio command line. It works for local or remotely hosted services. Its no good for ASMX-style .NET 2.0 SOAP services though.
if you want to test using only json, you could use some of the light weight Rest clients ex. Mozilla Rest plugin.
We test our SOAP APIs manually with SOAP UI and otherwise use jMeter for automated SOAP API testing. While having a GUI seems attractive first, I find both applications quiet user-unfriendly and time consuming to work with.
As already suggested, you could do it in code using Java or maybe use a dynamic language like Ruby:
Testing SOAP Webservices with RSpec
SOAP web Services testing in RUBY
As user mitchnull mentions in his comment:
Disabling the browser component (-Dsoapui.jxbrowser.disable=true)
solved the 100% CPU usage issues for me. (when it was enabled, it
periodically went to 100% CPU even when not running any
tests/requests).