I don't know if this is a common issue but in my symfony2 project when I load for the first time it takes around 4 seconds (Profiler saying) after a direct refresh , it takes around 100ms.
I know that it needs to create the cache that's why it takes a long time.
But when I wait around 10 mins and refresh, it takes again around 4s to load.
Does the cache get deleted and symfony2 tries to recreate it ?
How can I fix this issue?
It depends on what your setup is.
Could be the symfony cache being dropped, could be a mysql connection timing out and for some reason being slow to reconnect, could be the mysql cache being dropped.
You could lookup in the profiler where the time is used, maybe that gives you a clue.
Related
I need some information from you.I have used session.TimeOut=540 in application.Is that effects on my Application performance after some time.When number of users increases its getting very slow. response time nearly more that 2 minutes for a button click also.This is hosted in server in Application pool .I don't know about Application pool much.If Session Timeout is the problem i will remove it.Please suggest me the way to for more users.
Job Numbers,CustomerID,Tasks will come from one database.when the user click start Button then the data saved in another Database.I need this need to be faster for more Users
I think that you have some page(s) that make some work that takes time, or for some reason or a bug is keep open for more time than the usual.
This page is keep lock the session and hold the rest page from response because the session holds all the pages.
Now, together with the increase of the timeout this page is lock everything and here is you response time near to 2 minutes.
The solution is to locate the page that have the long running problem and fix it or make it faster by optimize the process, or if this page must keep the long time running, then disable the session for that one.
relative:
Web app blocked while processing another web app on sharing same session
What perfmon counters are useful for identifying ASP.NET bottlenecks?
Replacing ASP.Net's session entirely
Trying to make Web Method Asynchronous
Does ASP.NET Web Forms prevent a double click submission?
About server
Now from the other hand, if your server suffer from hardware, or bad setup then here is one other answer with points that you need to check to make it faster.
Find out where the time is spent
add the StopWatch in the method which you said "more that 2 minutes for a button click". you can find which statment spent the most time.
If it is a query on DB that cost time. Check your sql statement.
are you using "SELECT Count(*)" instead of "SELECT Count(Id)"? the * is always slower. also, don't try "SELECT * FROM...."
Use cache.
there are many ways to do cache. both in ASPX pages and your biz layer.
the OutputCache is the most easy way.
and also, cache the page (for example a blog post) on the first time when a user visit it.
Did you use memory paging?
be careful when doing paging on gridview or other list. If you just call DataSource=xxx and DataBind(), even with PagedDataSource, this is likely a memory paging. It cost a lot of performance. Please use stored procedures to do paging.
Check your server environment
where did you deploy the website? many ISP will limit brandwide and IIS connection count and also CPU time to your account.
if you have RD access to your server. you can watch CPU and memory usage to see if they are high when many user comes to your site. If the site is slow and neither CPU nor memory useage is high, it may be a network brandwide problem.
Here are some simple steps to narrow down the issue -
1) Get HTTPWatch (theres a free Basic version) available and check whats really taking time from an end user perspective. Look at number of requests, number of resources downloaded, and the payload. If there is nothing to worry move on to next
2) If its not client, then its usually the processing time on the server. Jump on to DB first - since this is quite easier to eliminate quickly. Look at how many DB calls are made (run profiler in staging or dev) and see if there are any long running queries, missing indexes or statistics, and note the IO. If all is well, move on
3) Check your app code. You could get on with VS.NET in build profiler or professional tools such as Ants. If code is fine then its your network or external calls that you make, check your network bandwidth. If you still cannot narrow down, check your environment/hardware
The best way to get to it is to apply load - You could use simple tools such as ab.exe (that comes as part of Apache Web server) to have concurrent hits on your server and run the App, DB profilers in the background to get to the issue.
Hope this helps!
We have a complex app that serves AJAX JSON streams (using ADO to grab the data) using brief ASP servlets. Any given session can fire up from 10-20 of these requests simultaneously. We encountered a significant performance problem way earlier than we expected as load built. (Server is a dual-XEON, RAID 5, 4gb, etc). Sleuthing around in perfmon we noticed that the 'Requests Executing' figure is perpetually stuck at 1. Never gets any higher. Research indicates that numbers of 20-50 are not uncommon. Requests Queued will hover around 10-20 and Wait Time climbs as well.
We have fiddled with ASPProcessorThreadMax set to 40 from default of 25 with no effect. It seems to be only able to work a single request at a time, which, needless to say, won't work. I can't find anything that describes this particular problem. Anny help is greatly appreciated.
ASP Session object is constrained to a Single Threaded Apartment (STA). As a result requests to ASP scripts for the same session can only be processed sequentially.
An additional reason why you might only ever see 1 executing ASP script even across multiple sessions is where debugging has be enabled for ASP. This causes the ASP processing to ignore ASPProcessorThreadMax and pretend it were set to 1.
To eliminate the problem ensure debugging is not enabled and turn off "Enable Session State". If you are using the Session object in your code you will need to find an alternative, like DB backed state.
However, how many active concurrent sessions are you expecting in the live production? Perhaps the overall user experience will not truely be impacted by the serialisation of requests per session.
Our users of a legacy web application written in ASP.net 2.0 are experiencing slow down after using the application over some time (after 2 hours or so).
For example, clicking a button performing some calculation and updating an ajax updatepanel takes several seconds while it is almost instant when they just have logged in.
If they log off and log back on of the web application, it gets back to the normal speed again, every time they do. The slow down is for a particular user and not global. It can fast for an user and slow for the user next to him.
I've looked at the IIS server and there is plenty of free memory in it and the CPU is almost always below 10%.
There are only a dozen users using this web application at time so scalability shouldn't be an issue.
The only think I can think of being affected by log offs, is session state.
I've already looked ViewState too and it is "only" 18kb at the slowest which shouldn't be the bottleneck, especially since they are on the same gigabit LAN and not remote. It is not any smaller when the applications runs fast.
Looking at session state in the code, it isn't used much and no large objects are stored.
According to my tests, it didn't grow bigger than 10 items and 500 bytes after a few minutes.
Even if there was a leak, the server should be able to cope with it considering the amounts of memory it has (4GB but only using 300MB).
I've cleared temporary files and it didn't seem to make any significant difference.
Do you think these slowdowns could come from something else than Session State, keeping in mind logging off and back on gets the speed back to normal?
If not, is there any tool you would suggest to profile sessionstate or a setting in IIS I should try to change?
what does the browser's memory use look like on the client machines when they experience the slowdown? It could be memory leaks in your javascript if you are using lots of ajax stuff and the browser's memory use continuously climbs.
Have you checked your database? (I assume you're consuming some data with an ajax app)
If you don't close the connection in the Finally block, you can wind up with zombie database connections that slow the app down. I don't know if this is the root cause, but probably worth looking at.
If this is an AJAX heavy page & the user is staying on the same page (i.e. lots of postbacks to itself) then it's possible that it's just ViewState growing to large. and the slow down you're experiencing is due to PageSize.
I would try and recreate the experience locally & monitor the page size/traffic with something like Firebug/Fiddler. If it is a ViewState/page size issue you could look at moving ViewState to the server side
See these for more info on it.
http://professionalaspnet.com/archive/2006/12/09/Move-the-ViewState-to-Session-and-eliminate-page-bloat.aspx
This has been a hard problem to diagnose and I was hoping someone could help me out.
We have an AIR app (www.trainerroad.com) that uses Native Process to read data from a command line that comes from a USB stick. It's a cycling app the data is heart rate, cadence, speed and power.
While someone workouts, we record that data to a sqlite database every second. We have a sqlite connection to the database. We have a timer that ticks every second and that's what triggers our inserts.
We have a few hundred users. A few of them have seen it where the app will run for 45 minutes fine, then hang for 30 seconds to a couple minutes. Then, it will release and the clock in the workout will tick down really fast. That means the timers are all getting hit.
This makes me think that something is hanging the app, but I can't figure out what. The app executed the same code every second for 45 or so minutes, then suddenly freezes. (btw, it isn't EVERY 45 minutes, but it does happen after the workout has been running for a while).
I'm thinking it has to do with SQLite. Maybe the database is being compacted while it's being executed against? I'm stumped and I can't reproduce this locally.
Does anyone have any ideas of how to debug this or what area of my app might be causing this? I know it's a hard one.
update
I ran the memory profiler for 20 minutes while it was running and I didn't see peak memory usage increase at all. I could tell it was garbage collecting by looking at the peak vs current memory usage.
I've added two system.gc() calls every 60 ticks. I'm hoping this doesn't make it gittery, but I'm not doing much while it plays so I think I should be good. Not sure if this is what was causing the problem though.
It looks like the manual garbage collection has fixed the issue. We haven't seen this since we put that upgrade in.
I'm working with ASP.Net web services and am having a problem with a long-running process that takes about 5 minutes to complete, and it's timing out. To fix this, I was able to set the executionTimeout on the server's web.config to 10 minutes, and then set the .Timeout property on the Web Service object to approximately 9 minutes. Now, I'm worried that this may possibly cause some other web service calls to sit there for 10 minutes before they time out rather than the previous 90-100 seconds. I know the default on the client side is 100 seconds, but wasn't sure if updating the server's timeout setting would affect this.
Bottom line is - Is it safe to update the server's timeout setting to a long amount like 10 minutes, and rely on the default timeout on the client, or could this end up causing some problems?
Thanks!
The web is not supposed to work like this. If you have a long running process, you should call it in a new thread and post the answer after the page has finish loading on the client side (either with a callback or by querying the server-side every x minutes to check if the process has finished). This way you avoid timeouts and the user gets their page (even incomplete) in a user-friendly time. This is important because if the user does not get their page in a reasonable time, they will be unhappy and try to reload the page (and maybe restart your process...).