I'm POST'ing a small image, so i'd like the timeout interval to be short. If the image doesn't send in a few seconds, it's probably never going to send. For some unknown reason my NSURLConnection is never failing, no matter how short I set the timeoutInterval.
// Create the URL request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]
initWithURL:[NSURL URLWithString:#"http://www.tumblr.com/api/write"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:0.00000001];
/* Populate the request, this part works fine */
[NSURLConnection connectionWithRequest:request delegate:self];
I have a breakpoint set on - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error but it's never being triggered. My images continue to be posted just fine, they're showing up on Tumblr despite the tiny timeoutInterval.
There's a thread on Apple dev forums discussing this issue. Apparently on iPhone OS, the setter mandates timeoutInterval a minimum of 240 seconds (4 minutes). This only occurs when the postBody is not empty (typically when using a POST request). This seems crazy, but apparently it's there to make sure requests leave the system even though it might take many seconds for the WWAN (3G) interface to wake up. 240 seconds seems rather steep, so they suggest to set a timer and cancel the asynchronous connection when your timer fires. I know this seems stupid, but that's the only I managed to get timeout for POST requests... :-(
As François mentioned above, the 240 seconds seemed to be working as he described up until iOS 6 (including on 5.1). Now, this timeout appears to take on the default value of 60 seconds as expected (if you didn't explicitly set it yourself), so if you have a POST request that might have relied on the longer time inadvertently, you might need to change the timeoutInterval manually to use a higher value. I've been able to set the timeout both below and above 60 seconds for a POST so it doesn't appear that the 60 second mark represents a minimum restriction to the timeout for this type of request either.
This issue is fixed in iOS5, So you won't be facing this problem now. And your code will work perfectly
Related
Sometimes, when an object is not in the cache, varnish will send an object that has a real size smaller than the size declared in the content-length header. For example - only part of the picture.
Is it possible to construct such a rule...?
if (beresp.http.content-lenght <> real_object_body_size) { return(retry); }
I wrote a script that tests the same request against the varnish and the backend. It compares the downloaded size with the content-lenght header. The backend, unlike varnish, sometimes ends up with a timeout but the size is always fine. The problem is rare but annoying because the objects are set to long user cache time.
After a few days I can say that the problem was in occasional backend problems with varnish's ability to send a chunked transfer if the object is not in the cache.
Thank you #Thijs Feryn for pointing this out. I knew about that property but until I read it here, I didn't connect it to my problem at all.
It seems that "set beresp.do_stream = false;" solved the problem.
I got strange behaviour of refresh ahead functionality.
Here is my configuration:
<cache-config>
<defaults>
<serializer>pof</serializer>
<socket-provider system-property="tangosol.coherence.socketprovider"/>
</defaults>
<caching-scheme-mapping>
<cache-mapping>
<cache-name>sample</cache-name>
<scheme-name>extend-near-distributed</scheme-name>
</cache-mapping>
</caching-scheme-mapping>
<caching-schemes>
<near-scheme>
<scheme-name>extend-near-distributed</scheme-name>
<front-scheme>
<local-scheme>
<high-units>20000</high-units>
<expiry-delay>10s</expiry-delay>
</local-scheme>
</front-scheme>
<back-scheme>
<distributed-scheme>
<scheme-ref>distributed</scheme-ref>
</distributed-scheme>
</back-scheme>
<invalidation-strategy>all</invalidation-strategy>
</near-scheme>
<distributed-scheme>
<scheme-name>distributed</scheme-name>
<service-name>sample</service-name>
<thread-count>20</thread-count>
<backing-map-scheme>
<read-write-backing-map-scheme>
<internal-cache-scheme>
<local-scheme>
<expiry-delay>10s</expiry-delay>
</local-scheme>
</internal-cache-scheme>
<cachestore-scheme>
<class-scheme>
<class-name>
com.sample.CustomCacheStore
</class-name>
</class-scheme>
</cachestore-scheme>
<refresh-ahead-factor>0.5</refresh-ahead-factor>
</read-write-backing-map-scheme>
</backing-map-scheme>
<autostart>true</autostart>
</distributed-scheme>
</caching-schemes>
</cache-config>
and if I request my service with a period of 6s (10s*0.5) seconds everything is fine. I have no delaying in response(except for the first time), but if i change a period to 3 seconds for example, then i start getting delays every 10 seconds. I have no idea why it is happening. It looks like if i request my service before expectable period (from 5 to 10 seconds) asynchronous loading doesn't happen even if after that i request it again. Is there any explanation of it and how can i bypass this behaviour?
Thanks
The problem has been solved. The reason why i've got such a situation is that front-scheme didn't notify the back-scheme because of the same expiration time. In a few words, to use refresh-ahead functionality with near cache you have to set expiration time of front-scheme equal to soft-expiration time(in that case it will be 10s*0.5).
I have an iPhone app which needs to load some data from a URL. I have the following line of code:
NSString *versionControlContents = [NSString stringWithContentsOfURL:[NSURL URLWithString:versionControlURL] encoding:encoding error:NULL];
The issue that I'm having is that if the contents of the URL have changed since the first time the URL was loaded, the changes aren't being reflected. Every subsequent time that line of code runs, versionControlContents ends up with the same content as the first time it ran.
I'm assuming this is because the iPhone has some sort of caching mechanism so that it doesn't actually load the data from the URL every subsequent time. How can I disable this temporarily?
Thanks!
You might try + requestWithURL:cachePolicy:timeoutInterval:
Then you can set your cacheing policy as you wish.
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSURLRequest_Class/Reference/Reference.html
In Cocoa, is there a notification i can register for, that informs me, when a new day begins - at 00h:00min:01s in the morning?
If it is for iPhone development, you can also listen for a UIApplicationSignificantTimeChangeNotification. It gets posted on more occasions than the arrival of midnight, but when you receive one, you can simply check if you are on or near midnight.
For Mac OS X, you would have to do what Tom Dalling suggests but you should also keep track of changes to the system clock yourself (in order to update your timer) as well as changes to the current time zone.
There's no notification that I know of. You can get a timer to fire whenever a new day begins like so:
[[NSTimer alloc] initWithFireDate:midnight
interval:60 * 60 * 24 //one day, in seconds
target:someObj
selector:#selector(someSelector)
userInfo:nil
repeats:YES];
The trick is getting an NSDate set to midnight. Check the Date and Time Programming Guide for how to do that with date components and the like.
EDIT: see this question for how to get the midnight NSDate.
As of iOS8, you can also directly listen to NSCalendarDayChangedNotification.
As mentioned by others, in iOS 8 you can use NSCalendarDayChangedNotification. In terms of how to do that, this post gives you more info.
Essentially NSCalendarDayChangedNotification requires that you go to your appDelegate file and insert the below code in app (adapted from guide for Swift 3):
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.dayChangedOperations(notif:)), name:NSNotification.Name.NSCalendarDayChanged, object:nil)
Where "ViewController" is the classname of one of my classes and "dayChangedOperations" is the name of the function that I want to run whenever the day changes.
Count Days Since Last Change
Note that all you get from this is an alert that the day changed. You are not given the number of days since the app last ran. So remember to save the date to a userDefault each time this function runs, so you can use it for comparison later.
My program puts a file into a remote host using HTTP. For some unavoidable
reasons, the remote hosts needs some time to acknowledge the final packet of
the data transmission. More time than the default timeout, which according
to my experience is around 30 seconds.
Therefore I wanted to increase the timeout to 5 minutes, using this code:
DWORD dwTimeout= 300000; // 5 minutes
pFtpConnection->SetOption( // KB176420: this has no effect on some
INTERNET_OPTION_SEND_TIMEOUT, dwTimeout); // old versions of IE.
pFtpConnection->SetOption(
INTERNET_OPTION_RECEIVE_TIMEOUT, dwTimeout);
pFtpConnection->SetOption( // NB: Docs say these 2 are not implemented.
INTERNET_OPTION_DATA_SEND_TIMEOUT, dwTimeout);
pFtpConnection->SetOption( // our own tests show that they are!
INTERNET_OPTION_DATA_RECEIVE_TIMEOUT, dwTimeout);
This is MFC code which boils down to calling
InternetOption(hConnection, INTERNET_XXX, &dwTimeout, sizeof(dwTimeout))
The problem is that this code apparently fails to modify the timeout on a
non negligeable proportion of computers where the program is used.
How can I reliably set the data connection timeout?
TIA,
Serge Wautier.
It looks like this WinInet isue can'tbe solved reliably.
I eventually switched from WinInet to Ultimate TCP/IP.