Subject: afp alarm child timed out seems to lead to dissappearing server in choser

From: "Markus Koch" <[email-masked]>
Date: Sun, 22 Jul 2001 03:45:58 +0200

Hi

Once in a while the whole appletalk network goes down for a period of 1 to 5
minutes: the server (and all other macs) dissapear from the choser on every
computer, without any appearent reason. Even the windows clients (samba)
have problems accessing the server. It almost looks like the network raffic
is to much to do anything.
I am running 1.4b2+asun2.1.3 on a Suse system. The kernel is a plain (not
suse) 2.2.16 with raidpatch.
Here is a part from syslog during one of these downperiods.

Jul 11 16:08:53 base afpd[5666]: afp_alarm: child timed out
Jul 11 16:08:53 base afpd[5666]: 29.55KB read, 70.70KB written
Jul 11 16:08:53 base afpd[342]: server_child[1] 5666 exited 1
Jul 11 16:08:53 base afpd[5556]: afp_alarm: child timed out
Jul 11 16:08:53 base afpd[5556]: 24.99KB read, 108.03KB written
Jul 11 16:08:53 base afpd[342]: server_child[1] 5556 exited 1
Jul 11 16:09:06 base afpd[6044]: afp_alarm: child timed out
Jul 11 16:09:06 base afpd[6044]: 6393.42KB read, 186858.25KB written
Jul 11 16:09:06 base afpd[342]: server_child[1] 6044

Although the afpd´s died here, at 16:12 the connections came back without
any new entries in the log.

Anyone a hint? BTW what does this child timed out mean? What has happend?

thanks
markus

---

From: Thomas Kaiser <[email-masked]>
Date: Mon, 23 Jul 2001 11:41:56 +0200

on Sun, 22 Jul 2001 03:45:58 +0200, Markus Koch wrote:

> computer, without any appearent reason.

Does your switch indicate high traffic / many collissions if the problem
appears?

> Even the windows clients (samba) have problems accessing the server.

They are connecting via TCP/IP, so it's not an AppleTalk-specific problem.

> It almost looks like the network raffic is to much to do anything.

You should check the network connection on lower layers, to see what's going
wrong there.

In these situations, use 'ping' from the servers terminal to check whether
other hosts are reachable _via TCP/IP_ (if your network behaves normal you
can get a list of ip addresses by entering '/usr/sbin/arp -n' on your
server.

To check the AppleTalk-side you can use 'aecho [AppleTalk address]'. You
probably will not be able to use AppleTalk (NBP-) names in this case, so you
should create a list of AppleTalk names to AppleTalk addresses table with
'nbplkup' before.

You should also try to nail the problems down using a packet sniffer like
tcpdump. Maybe there are broadcast storms which prevent the transmission of
normal packets?

> BTW what does this child timed out mean?

After a specific amount of time, the afpd gets no response from a mac, it
thinks the mac had crashed or has been disconnected from the network and
therefore this afp session timed out.

Regards,

Thomas