Closed Bug 453672 Opened 17 years ago Closed 17 years ago

something really slow www.mozilla.org from the office network

Categories

(mozilla.org Graveyard :: Server Operations, task)

Product:
mozilla.org Graveyard
Component:
Server Operations
Platform:
All
Other
Type:
task
Priority:
Not set
Severity:
normal

Tracking

(Not tracked)

Status:
RESOLVED WORKSFORME

People

(Reporter: dbaron, Assigned: aravind)

Details

Since I got back yesterday, access to many mozilla.org Web sites from the office network (wired network in Building S) has been really slow for me. (Pages like bugzilla, tinderbox, www.mozilla.org, etc., take 10 seconds or more to load -- sometimes even 30-60 seconds.) Non-Mozilla sites are performing normally. The problem might be related to DNS, because I've observed the following: If I do "ping www.mozilla.org", I get very fast ping responses, but it takes ping multiple seconds to print out the response and then do the next ping (note the total time at the bottom): $ ping www.mozilla.org PING www.mozilla.org.usgscac.cdnetworks.net (64.245.124.44) 56(84) bytes of data. 64 bytes from 64.245.124.44: icmp_seq=1 ttl=53 time=10.8 ms 64 bytes from 64.245.124.44: icmp_seq=2 ttl=53 time=11.0 ms 64 bytes from 64.245.124.44: icmp_seq=3 ttl=53 time=10.3 ms 64 bytes from 64.245.124.44: icmp_seq=4 ttl=53 time=10.4 ms 64 bytes from 64.245.124.44: icmp_seq=5 ttl=53 time=10.4 ms --- www.mozilla.org.usgscac.cdnetworks.net ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 20099ms rtt min/avg/max/mdev = 10.394/10.643/11.042/0.260 ms however, if I do "ping -n www.mozilla.org", things are quite snappy: $ ping -n www.mozilla.org PING www.mozilla.org.usgscac.cdnetworks.net (64.245.124.38) 56(84) bytes of data. 64 bytes from 64.245.124.38: icmp_seq=1 ttl=53 time=12.8 ms 64 bytes from 64.245.124.38: icmp_seq=2 ttl=53 time=10.4 ms 64 bytes from 64.245.124.38: icmp_seq=3 ttl=53 time=10.6 ms 64 bytes from 64.245.124.38: icmp_seq=4 ttl=53 time=10.4 ms --- www.mozilla.org.usgscac.cdnetworks.net ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3000ms rtt min/avg/max/mdev = 10.404/11.097/12.894/1.045 ms
Actually, I see the same ping behavior from home, but the sites are faster from home.
Is this all from your laptop by any chance? Do you have ipv6 enabled? Most OSes if you have ipv6 enabled, will try to use it first, then fall back on ipv4 when it fails, and the symptoms are almost exactly what you're describing. Disabling ipv6 often fixes the problem.
Summary: something really slow about DNS for mozilla sites from the office network → something really slow www.mozilla.org from the office network
It's from my laptop, via wired network, but disabling ipv6 doesn't seem to help. I also thought IPv6 was supposed to work from the office network.
(I tried disabling IPv6 both by deleting the ipv6 address from the eth0 interface and the pref in Firefox.) But the problem seems to appear and disappear every few minutes.
(And note that I think the reason all the other sites are slow to load is that they're waiting on a style sheet load from www.mozilla.org.)
ipv6 hasn't worked here for some time (fyi)
Also, I sort of don't think it's an IPv6 issue given that what I see at the command line is: $ telnet www.mozilla.org 80 Trying 64.245.124.38... almost instantaneously, and then a long hang at that point.
(In reply to comment #7) > Also, I sort of don't think it's an IPv6 issue given that what I see at the > command line is: > > $ telnet www.mozilla.org 80 > Trying 64.245.124.38... > > almost instantaneously, and then a long hang at that point. I've tried this several times today on my wired and computer and again on my wireless computer. I instantaneously get: mrz-mp:~ mrz$ telnet www.mozilla.org 80 Trying 64.245.124.38... Connected to www.mozilla.org.usgscac.cdnetworks.net. Escape character is '^]'. ^] telnet> Connection closed. This is under OSX, if that matters.
Assignee: server-ops → mrz
I could be wrong about ipv6 - aravind has similar problems and disabled v6 in Firefox. Assigning to him.
Assignee: mrz → aravind
For what it's worth, I haven't seen this for a few days now.
Well, I saw it again just now, but it went away once I'd had a chance to read "man tcpdump".
OK, I just had the hang again in my browser (loading two pages), so I started tcpdump -w file, did "telnet www.mozilla.org 80", and the telnet hung for probably ~30 seconds, and then connected. (I typed "Connection: close" into it and then enter twice, which wasn't the right syntax since I didn't make a request.) The two page loads in the browser finally finished a few minutes later, and I stopped the tcpdump after those loads finished. The www.mozilla.org address that I connected to in the telnet command was 64.245.124.41 (from the telnet output). My address (today) is 10.250.2.236. I'll attach the tcpdump output as a private attachment if there's anything you want to look for in it.
dbaron says this doesn't seem to be an issue anymore. Please re-open if needed.
Status: UNCONFIRMED → RESOLVED
Closed: 17 years ago
Resolution: --- → WORKSFORME
Product: mozilla.org → mozilla.org Graveyard
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