I have done something silly and written a script for a website that does an ajax check every 2 seconds. In this case its using wordpress and its admin-ajax.php file every 2 seconds. This essentially burned up all the CPU power of the server, and made every site on the server run really slowly.
After a lot of detective work, i finally found the script and stopped it, so that it doesn't happen on new loads of that website. But looking at my apache log, i can see that it is still running in one browser somewhere.
Is there a way for me to stop that browser from requesting that ajax-call, or perhaps block it from my server? Or will I just have to wait until that browser is being refreshed or closed?
Try to use netstat or something similar through ssh to detect the IP and port of the unknown browser. Also you should try to reboot the server so it may will loose connection.
PS: It's pretty hard to give a clue or answer in the right direction without having any logs or evidence to ensure you answer to this question correctly.
Related
When I issue an $.ajax query with a timeout: parameter, and my timeout is met such that error: is invoked, what does that mean?
More specifically:
does that mean the server received the request, but is still processing it? That may mean some effect may occur, so I may have to cancel it on the server, or somehow invalidate data that was already partially written to a database.
Or does that mean I was never able to reach the server at all? This is nice to know since then I don't have to deal with partial data on a server "save"
Or does that mean the request made it part of the way, and now we lost track of it? In this case, I'd have to actually ask the server, "Oh hey, about that request I sent awhile ago... did you get that one? yeah? okay ignore that last save"
OS Commands like tracert make it clear there may be many servers for a TCP command to go through, so if one becomes unresponsive, it's hard to tell if it got it or not. But some protocols require an echo-back to be considered receivable (so I'm not sure if HTTP or Apache is involved in this)
It is how long the client will wait to hear from the server before giving up.
The server may or may not have done its part. The only way for the client to know about that is for the client to be notified. Since you don't want to to leave a process or a human waiting forever, by using a timeout you specify the time to wait for success before giving up.
Practical Challenge:
I have a LR script that runs against an app being mocked and do not have a logout button (yet).
The test runs fine With stable response time for about 10 minutes, but after that the response time peaks and the server goes into 99% memory usage and transactions start to fail.
I suspect this is due to the script does not terminate the vusers after each run anf it builds up a lot of running sessions against the server wich is not terminated. But I might be wrong.
Anyays I want to programatically close each run after it has competed the business process.
I have red somewhere that web_set_sockets_option ("SHUTDOWN_MODE", "ABRUPT") could be used for this, but I want to be sure that this function actually does what I want and what does 'ABRUPT' means?
Are there better ways of closing sessions? Clicking the close browser during recording does not result in anything being captured in the script.
It's a server issue on session aging. Your server admin for your website can adjust the timeout values where no activity has taken place on a given session. By default most places have this set at 30 minutes. Trim it to what you need rather than taking the default value on the server.
Also, you may have hit a leak situation if resources are constantly accumulated on the server side but never released.
Based on your question I assume you're using the WEB/HTML protocol. I agree that the core issue is that your app's sessions should expire more elegantly and probably sooner. But, in order to get beyond this while testing you can try this. It isn't a guarantee, but it has worked sometimes for me in the past when dealing with similar situations. Try changing your Run-time Settings for the script:
Run-time Settings > Browser > Browser Emulation
Make sure you have the box checked for "Simulate a new user on each iteration". You can also try playing with the other settings here, like clearing the cache each iteration. This could cause a new connection setting with the web page for each iteration depending on the server's session settings. Again, this isn't 100%, but it has worked for me from time to time.
try this:
web_set_sockets_option("CLOSE_KEEPALIVE_CONNECTIONS", "1");
I am using Meteor on Heroku (free tier) with MongoHQ. My app is very simple right now, it loads 3-4 entries from a Collection, but when I deploy it to Heroku, I am seeing ridiculous load times (1-2 minutes). The HTML is rendered immediately. When I deploy to Meteor.com's free server, load times are a lot lower but still about 15 seconds for 4 tiny pieces of data. I'm not seeing this whatsoever when I deploy locally, app pulls data from the DB right away.
It is worth noting that I don't think it's an "idling" issue for Heroku. Even if I already have one browser window with the app just opened, if I use a different browser and try again I still get 1-2 minute load times. Once the data is loaded, however, performance goes back to being great, I can read and write with no problems.
What am I missing? I'm not seeing any errors in the console, mongo shows several queries in the logs and shows that it is responding quickly with 4 documents, but apparently somewhere in the middle there's a traffic jam. Any help with this is greatly appreciated, if I can't get past this Meteor is useless for my needs right now.
UPDATE: I've been watching it closely in Firebug, and it looks like the performance is largely inconsistent. Sometimes a simple refresh will take 1 minute, sometimes it will take 10 seconds. But what I've noticed is that the times when its slow, it GETs the sockjs/info file, then right after that the sockjs POST is aborted (sometimes multiple times). When it runs fast, the POST and subsequent POSTs run smoothly
Slow:
GET http://pocleaderboard.herokuapp.com/sockjs/info 200 OK 22ms
POST http://pocleaderboard.herokuapp.com/sockjs/029/su0d77fb/xhr Aborted
GET http://pocleaderboard.herokuapp.com/sockjs/info 200 OK 27ms
POST http://pocleaderboard.herokuapp.com/sockjs/132/uljqusxd/xhr Aborted
GET http://pocleaderboard.herokuapp.com/sockjs/info 200 OK 28ms
POST http://pocleaderboard.herokuapp.com/sockjs/154/kcbr6a5p/xhr Aborted
Fast(er):
GET http://pocleaderboard.herokuapp.com/sockjs/info 200 OK 1.08s
POST http://pocleaderboard.herokuapp.com/sockjs/755/xiggb555/xhr 200 OK 1.02s
Meteor gets loaded that fast locally, because it doesn't depend on your internet connection and the files can just be read from your harddrive and don't need to be downloaded.
And once the data is loaded it's the same everywhere you host, because the client (you) perform all actions on your cached mongo database and then just wait for the server to say if the action was alright or not.
But for the Heroku loading times, I have no idea, Sorry!
UPDATE:
These are the long-pulls from SockJS that is used by Meteor.
Normally these pulls only get Aborted on a hot code push (when a file is added/changed/removed).
Either you or Heroku seem to write or change something in the directory.
Because then a hot code push may be initiated by Meteor.
Heroku may not support web-sockets, which means you're stuck with the slower polling approach. See this:
https://devcenter.heroku.com/articles/using-socket-io-with-node-js-on-heroku
I am using xampp version 1.7.7 on windows 7. I am trying to do that when you click save image it would send information to save_record.php in the background. I do this with
$.ajax({
url: 'save_record.php',
data: values.join("&"),
success: function(data) {
//document.write(data);
}
});
And it is clearly not the issue. The problem is that the response is very slow and I am unable to find the reason for it. Below I add the data I received from chrome speed tracer. Firebug is also showing all responses above 1 second. They come in format like 1055ms or 1035ms which makes me think it gets stuck somewhere for one second. If that was not weird enough, it starts making the requests fast (30-50ms) at some time and that is a perfectly usable application for me. Otherwise that 1 second delay is killing it. I once killed process explorer.exe and added as a new task and it worked. But the next time it didn't. I restarted the pc - it is one second... And while I was typing this question it started doing those fast requests. Once it starts doing them fast it's all good, but when I start xampp (or open my laptop from sleep) it is usually slow (1sec+). This is a somewhat self solving problem after some time (like 5-10mins usually), but it is annoying and both curious as why this is happening :) Hopefully I was clear about the problem.
P.S. I tested and the difference in time from first php tag to last one is ~20 ms, so I assume it is not PHP cache that is acting up?
P.S.2. I would provide any other data needed, just not sure what to look at :) Just name it.
UPDATE: added Chrome's network tab.
UPDATE: after reinstallation of xampp the problem still persists:
Uncommenting the line 127.0.0.1 localhost in C:\Windows\System32\drivers\etc\hosts solved the problem. The speed just jumped up incredibly. I found this advice in here. Actually even the speed of Chrome opening other pages increased a lot o.O
Can you take a screen shot of network > Timing tab of chrome developer tool for the request which takes more than a second and share it. For eg.
You must analyze the time taken for each action mentioned in that tab. And also check the event trace from the speed tracer to get more information.
Try changing the content of save_record.php to <?php die(); ?> and see what happens. I suspect it's some kind of delay in processing the save_record operation on the server-side (could be DB is the bottleneck, could be file I/O, etc).
save_record.php ,
what code have you written if you doing any database operation may the operation is taking to much time can you provide me the code of "save_record.php" the i can able to optimize response or can able solve your query
I am wondering where this comes from : I have a 2 field form for a site that I am building and for some reason, the post request takes up to 13 seconds to complete, according to firebug... The script literally just sends an email in plain text with the user inputs and that's it, nothing complicated.
I am wondering where that delay could come from, any idea ?
Here is a link to a dev version : http://vps-sd.com/sd2012/
I tend not to click links to sites I don't trust, but it could be either
1) Network latency. Are you on a vpn? Where is the dev server hosted? You can use traceroute or something like that to follow the request from the command line.
If both the client and the server are on your dev box this should not be an issue.
2) For really long requests, I think it is more likely something in your dev server is screwed up. It could be the code, or it could be that the dev server is having some issues. Did you log onto the dev server and look at its load? Has some process gone haywire? Has it used all its memory? Did you add some simple benchmarking code to the application server?
You need to diagnose where exactly the slowdown is.