[Systems] Diagnosing download errors was Re: Physics review

[David Farning]

CCing systems.

Walter pointed out that he was have trouble with activities.sl.o
sending back 404 errors.  Following are some techniques that I use to
diagnose activities.sl.o and download.sl.o errors.

Run 'php -f maintenance.php publish_files' as the activites user on
sunjammer.  This script re-copies all necessary files from the sandbox
to the public repo. Is useful to insure that the permission are set
correctly to allow activities.sl.o to write to the public repo.

Next look to insure that the file you just tried to make public is
available via http://download.sugarlabs.org/activities .  If it is
available here the mirror system is recognizing it correctly.

I am pretty sure that the above step are working correctly.

The part that I am more doubtful about is the activities.sl.o
redirector.  Whenever you get a 404 error, try to download the file
with 'wget -v'  For example:
1. Right click on the download button and 'copy link location'
2. Go to to command line and wget -v <link location>
3. You will get output like the the following.

dfarning at acer:~$ wget -v
http://activities.sugarlabs.org/en-US/sugar/downloads/latest/4222/addon-4222-latest.xo?src=addondetail
--2009-10-24 15:48:22--
http://activities.sugarlabs.org/en-US/sugar/downloads/latest/4222/addon-4222-latest.xo?src=addondetail
Resolving activities.sugarlabs.org... 140.186.70.53, 2002:8cba:4635::1
Connecting to activities.sugarlabs.org|140.186.70.53|:80... connected.
HTTP request sent, awaiting response... 302 Found
Location: http://activities.sugarlabs.org/en-US/sugar/downloads/file/26322/xpi/sliderule-2.xo?src=addondetail
[following]
--2009-10-24 15:48:23--
http://activities.sugarlabs.org/en-US/sugar/downloads/file/26322/xpi/sliderule-2.xo?src=addondetail
Reusing existing connection to activities.sugarlabs.org:80.
HTTP request sent, awaiting response... 302 Found
Location: http://download.sugarlabs.org/activities/4222/sliderule-2.xo
[following]
--2009-10-24 15:48:23--
http://download.sugarlabs.org/activities/4222/sliderule-2.xo
Resolving download.sugarlabs.org... 140.186.70.53, 2002:8cba:4635::1
Reusing existing connection to activities.sugarlabs.org:80.
HTTP request sent, awaiting response... 302 Found
Location: http://mirrors.rit.edu/sugarlabs/activities/4222/sliderule-2.xo
[following]
--2009-10-24 15:48:23--
http://mirrors.rit.edu/sugarlabs/activities/4222/sliderule-2.xo
Resolving mirrors.rit.edu... 129.21.171.98
Connecting to mirrors.rit.edu|129.21.171.98|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 26802 (26K) [application/octet-stream]
Saving to: `sliderule-2.xo'

100%[================================================================================================================================================================>]
26,802      --.-K/s   in 0.1s

2009-10-24 15:48:43 (219 KB/s) - `sliderule-2.xo' saved [26802/26802]

dfarning at acer:~$

1. activities.sl.o determines path to the latest publicly available file.
2. activities.sl.o passes the path of the file to download.sl.o .
3. download.sl.o passes the path of the file to a mirror.
4. The mirror responds by send the file back to  the original requester.

hope this helps - from the outside a.sl.o and d.sl.o look like fragile
black boxes.
david