Re: [9fans] mail problems..

Re: [9fans] mail problems..

[Lucio De Re]

I thought I had a problem, and now I have to establish the nature of
the problem.  Presumably some inconsistency between the kernel, fossil
and venti.

I have just rebuilt the fossil and venti services, mkfs/mkext'd the
most recent image I have available (May 20th or thereabouts) onto the
fossil, then ran 'snap -a' as suggested in the wiki.

A fossil/flchk produces two bad blocks:

warn: unreacheable block: addr 94d0 type 8 tag 26fba734 state 5,Venti epoch 2 close 4294967295
warn: unreacheable block: addr 94d1 type 8 tag 3ee3966b state 5,Venti epoch 2 close 4294967295

Should I be looking to venti or fossil for this problem?

This is running off a slightly older snapshot, I think.  I'm using a
modified 9pccpu with a SCSI-based kfs.

++L

[9fans] Fossil problems (Was: mail problems..)

[Lucio De Re]

Oops, I really blundered with this one.  I changed the subject
header...

++L

On Thu, Jun 26, 2003 at 01:43:07PM +0200, Lucio De Re wrote:
>
> I thought I had a problem, and now I have to establish the nature of
> the problem.  Presumably some inconsistency between the kernel, fossil
> and venti.
>
> I have just rebuilt the fossil and venti services, mkfs/mkext'd the
> most recent image I have available (May 20th or thereabouts) onto the
> fossil, then ran 'snap -a' as suggested in the wiki.
>
> A fossil/flchk produces two bad blocks:
>
> warn: unreacheable block: addr 94d0 type 8 tag 26fba734 state 5,Venti epoch 2 close 4294967295
> warn: unreacheable block: addr 94d1 type 8 tag 3ee3966b state 5,Venti epoch 2 close 4294967295
>
> Should I be looking to venti or fossil for this problem?
>
> This is running off a slightly older snapshot, I think.  I'm using a
> modified 9pccpu with a SCSI-based kfs.
>
> ++L

Re: [9fans] mail problems..

[steve.simon]

[-- Attachment #1: Type: text/plain, Size: 193 bytes --]

I used to scan POP every 45 secs but got shouted at by the TI dep.
I was asked to scan no more than every 5 mins - thought our POP3
server is a CCmail database so enough said (sigh)

-Steve

[-- Attachment #2: Type: message/rfc822, Size: 847 bytes --]

From: 9fans@cse.psu.edu
To: 9fans@cse.psu.edu
Subject: Re: [9fans] mail problems..
Date: Thu, 26 Jun 2003 02:58:37 +0100
Message-ID: <2937630799@snellwilcox.com>

> By default, "periodically" means every 60 seconds, which is not a very
> good choice if you have a dial-up connection or a busy mail server (or
> both).  You can change this to N seconds by writing to /mail/fs/mbox/ctl
> the (undocumented?) control message 'refresh N'.

Is this too frequent or not frequent enough?  I usually do 15 seconds.

Russ

[9fans] mail problems..

[Apurva Mehta]

I have been trying to use plan 9 to check my email but I am getting
stuck. I have a pop3 account with gmx.net and here is what I have
typed on the command line to check it..

upas/fs -f /pop/pop.gmx.net/my_user_name

The first time I did that, I was asked for my password. It accepted it
and the I got the term% prompt again.

When I executed 'mail' from acme, it said that I had 0 messages. I
know for a fact that there were messages on the server, why were they
not downloaded?

Also, I am confused about how to send mail using an authenticated smtp
server. What do the different rewrite files do? I have edited my
rewrite.gateway file to point to my smtp server (mail.gmx.net). But
how do I handle authentication? I have also added a 'From' header file
in my /mail/box/user_name/headers file. Will this 'From' header be
used for every email I send from my account?

	- Apurva

Re: [9fans] mail problems..

[Dan Cross]

> upas/fs -f /pop/pop.gmx.net/my_user_name
>
> The first time I did that, I was asked for my password. It accepted it
> and the I got the term% prompt again.
>
> When I executed 'mail' from acme, it said that I had 0 messages. I
> know for a fact that there were messages on the server, why were they
> not downloaded?

It sounds like acme was running in a different namespace and thus didn't
see the /mail/fs that was being presented by upas/fs talking to the POP3
server.  Did you run acme in the same window you ran upas/fs in?

> Also, I am confused about how to send mail using an authenticated smtp
> server. What do the different rewrite files do? I have edited my
> rewrite.gateway file to point to my smtp server (mail.gmx.net). But
> how do I handle authentication? I have also added a 'From' header file
> in my /mail/box/user_name/headers file. Will this 'From' header be
> used for every email I send from my account?

Well, you should move rewrite.gateway to rewrite.  Authentication is
handled using smtp; change /mail/lib/remotemail such that, when it
invokes smtp, it supplies the ``-a'' and ``-u <your_user_name>''
options.  Note that authentication is a little picky in that the SMTP
server must support TLS for it to work.  The client won't authenticate
by sending a password over an unencrypted connection.  Make sure your
password on the mailserver is in a factotum that smtp can see (if
you're just using a standalone machine, that's your normal factotum).
Something like:
echo 'key proto=pass service=smtp server=''your.mail.server'' !password=''your_password''' >> /mnt/factotum/ctl
(You may not need to quote the mailserver name, nor the password, but
it won't hurt anything).

	- Dan C.

Re: [9fans] mail problems..

[Apurva Mehta]

On Tue, 24 Jun 2003 11:24:09 -0400
Dan Cross <cross@math.psu.edu> wrote:

>
> It sounds like acme was running in a different namespace and thus
> didn't see the /mail/fs that was being presented by upas/fs talking
> to the POP3 server.  Did you run acme in the same window you ran
> upas/fs in?

Thanks, I ran mail from the window I ran upas/fs from and I could read
my mail. However, it does not store a local copy of the messages, it
seems to download them from the server everytime I access my mail
box.. Is there any way to make it download a local copy while leaving
the original message on the server?

> Well, you should move rewrite.gateway to rewrite.  Authentication is
> handled using smtp; change /mail/lib/remotemail such that, when it
> invokes smtp, it supplies the ``-a'' and ``-u <your_user_name>''
> options.  Note that authentication is a little picky in that the
> SMTP server must support TLS for it to work.  The client won't
> authenticate by sending a password over an unencrypted connection.
> Make sure your password on the mailserver is in a factotum that smtp
> can see (if you're just using a standalone machine, that's your
> normal factotum). Something like:
> echo 'key proto=pass service=smtp server=''your.mail.server''
> !password=''your_password''' >> /mnt/factotum/ctl(You may not need
> to quote the mailserver name, nor the password, but it won't hurt
> anything).

I did that, but my messages do not seem to be reaching the recipients.
I will wait and see, but usually my smtp server delivers messages
almost instantly. BTW, I ran 'mail recipient_address' on the command
line and typed in a message. I then hit ESC and CTRL+D. Since I have
used justqmail in my rewrite file, I executed '/mail/lib/kickqueue'.
There was some activity on my modem and I got the prompt back..

Is this the correct way of going about sending mail? Also, my
smtp service requires that the address I am sending from should be an
@gmx.net address. I have added the line : "From: "Apurva Mehta"
<apurva@gmx.net> to my /mail/box/user_name/headers file. Will this
ensure that the 'from' address is as required by the service?

	- Apurva

Re: [9fans] mail problems..

[Russ Cox]

> Thanks, I ran mail from the window I ran upas/fs from and I could read
> my mail. However, it does not store a local copy of the messages, it
> seems to download them from the server everytime I access my mail
> box.. Is there any way to make it download a local copy while leaving
> the original message on the server?

It downloads every time you start it, but it does not delete them,
and if you leave it running, then it will dial out periodically
to check for new messages but not redownload the old ones.
If you delete them via mail or Mail, they get deleted from the
server.

Every time you run the "mail" command, it will dial out just to
see if there are new messages.  That might be the delay you are seeing.

> I did that, but my messages do not seem to be reaching the recipients.
> I will wait and see, but usually my smtp server delivers messages
> almost instantly. BTW, I ran 'mail recipient_address' on the command
> line and typed in a message. I then hit ESC and CTRL+D. Since I have
> used justqmail in my rewrite file, I executed '/mail/lib/kickqueue'.
> There was some activity on my modem and I got the prompt back..

tail /sys/log/smtp and /sys/log/mail.  Probably an error occurred
and they got dropped on the floor (the bounces bounced too).
You can look at the queue in /mail/queue/$user.

> Is this the correct way of going about sending mail? Also, my
> smtp service requires that the address I am sending from should be an
> @gmx.net address. I have added the line : "From: "Apurva Mehta"
> <apurva@gmx.net> to my /mail/box/user_name/headers file. Will this
> ensure that the 'from' address is as required by the service?

Sure, but you also need to edit /mail/lib/remotemail to set the
from domain there.  The headers file just affects the headers,
not the smtp envelope.

Russ

Re: [9fans] mail problems..

[Richard Miller, miller]

> It downloads every time you start it, but it does not delete them,
> and if you leave it running, then it will dial out periodically
> to check for new messages but not redownload the old ones.

By default, "periodically" means every 60 seconds, which is not a very
good choice if you have a dial-up connection or a busy mail server (or
both).  You can change this to N seconds by writing to /mail/fs/mbox/ctl
the (undocumented?) control message 'refresh N'.

Re: [9fans] mail problems..

[Russ Cox]

> By default, "periodically" means every 60 seconds, which is not a very
> good choice if you have a dial-up connection or a busy mail server (or
> both).  You can change this to N seconds by writing to /mail/fs/mbox/ctl
> the (undocumented?) control message 'refresh N'.

Is this too frequent or not frequent enough?  I usually do 15 seconds.

Russ

Re: [9fans] mail problems..

[Scott Schwartz]

> Is this too frequent or not frequent enough?  I usually do 15 seconds.

Our computer center won't let you poll the POP server more often than
once every few minutes.

Gripe: why don't ISPs pick some way to notify POP users, instead of
making them poll.  comsat wasn't rocket science, and all the instant
messager programs these days are a plausible alternative.

Re: [9fans] mail problems..

[boyd, rounin]

> Gripe: why don't ISPs pick some way to notify POP users, instead of
> making them poll.  comsat wasn't rocket science, and all the instant
> messager programs these days are a plausible alternative.

hmm,  i'd like to hear your design that would be reliable and scale
to thousands of users.  iirc, comsat was a toy that ran on old
machines in very limited user environments.

reliable scaleability is a hard problem.

Re: [9fans] mail problems..

[Scott Schwartz]

| hmm,  i'd like to hear your design that would be reliable and scale
| to thousands of users.

How about zephyr?  Or AIM?

| reliable scaleability is a hard problem.

Fine, so do best effort delivery and retry every 10 minutes.

Re: [9fans] mail problems..

[boyd, rounin]

> Fine, so do best effort delivery and retry every 10 minutes.

best effort?  no way.

maybe this might be an interesting read?

     http://www.strakt.com/~jacob/ifc-accu.ps

Re: [9fans] mail problems..

[Scott Schwartz]

Oh, come on... just to indicate that email is waiting?
A udp packet once in a while is more than enough.

It's all fantasy anyway.  People won't stop polling,
because their pop clients will continue to let them.

Re: [9fans] mail problems..

[boyd, rounin]

> Oh, come on... just to indicate that email is waiting?
> A udp packet once in a while is more than enough.

UDP?  is that reliable?  does it scale?

Re: [9fans] mail problems..

[Dan Cross]

I think Scott's point is that, for this application, it doesn't matter.
A UDP packet that said, ``hey, you just got mail,'' would certainly scale
to thousands of users.  Unfortunately, no user agent software supports
such a thing, and most over-zealous firewall administrators would block
it anyway.  In that case, one could certainly fallback to polling.

	- Dan C.

Re: [9fans] mail problems..

[boyd, rounin]

the whole thing is a fiasco.  it is next to impossible to get mail
notification 'right' and if it were my firewall(s) next to nothing
would be allowed to wander through.  isn't that the point?

having said that, firewalls are are just all wrong.

tomorrow is 'will do tcp/ip for food day', plus a chat to the
Swedish Embassy -- that should be fun :)

gawd, tcp is 20+ years old iirc ...

Re: [9fans] mail problems..

[andrey mirtchovski]

On Thu, 26 Jun 2003, boyd, rounin wrote:

> the whole thing is a fiasco.  it is next to impossible to get mail
> notification 'right'

mail notification seems to work right with plumbing...

Re: [9fans] mail problems..

[boyd, rounin]

> mail notification seems to work right with plumbing...

i'm thinking on a slightly more global scale ...

Re: [9fans] mail problems..

[andrey mirtchovski]

On Thu, 26 Jun 2003, boyd, rounin wrote:

> > mail notification seems to work right with plumbing...
>
> i'm thinking on a slightly more global scale ...
>

i'm sorry, i was thinking on a scale appropriate for this list :)

Re: [9fans] mail problems..

[okamoto]

> gawd, tcp is 20+ years old iirc ...

then, what is your solution?

Kenji

Re: [9fans] mail problems..

[boyd, rounin]

> then, what is your solution?

specification of the problem would be a start.

Re: [9fans] mail problems..

[Scott Schwartz]

| > Oh, come on... just to indicate that email is waiting?
| > A udp packet once in a while is more than enough.
|
| UDP?  is that reliable?  does it scale?

Sure.  It works fine for much larger things, like DNS and AIM.  It's just
the right tool for this job.

Re: [9fans] mail problems..

[boyd, rounin]

> Sure.  It works fine for much larger things, like DNS and AIM.  It's just
> the right tool for this job.

http://www.theregister.co.uk/content/6/31392.html

Re: [9fans] mail problems..

[matt]

boyd, rounin wrote:

>>Sure.  It works fine for much larger things, like DNS and AIM.  It's just
>>the right tool for this job.
>>
>>
>
>http://www.theregister.co.uk/content/6/31392.html
>

That seems to suggest that UDP works for billions of daily DNS requests.

Sounds like a few thousand mail clients per server would be well with
its capability.

It might make you reconsider knowing that Hotmail / Passport / MSN
Messenger offer that exact service.
Messenger notifies you if you have any Hotmail mail arrive, if that
isn't a proof of concept then I don't know what you would consider.

If the Beast can make it work for Hotmail & Windows then surely using
distributed computing should make it all the easier and less resource
hungry.

Sounds to me that this would be the sort of application for which the
use of Secstore/Factotum is intended.

Authenticating the sender will be mandated for communications with
Government somewhere soon, be that tax returns or road tolls or
something. Microsoft is already trying to get Passport as the de-facto :
http://theregister.co.uk/content/archive/24938.html

Re: [9fans] mail problems..

[boyd, rounin]

> That seems to suggest that UDP works for billions of daily DNS requests.

sure, and the reason it works is cos of the TCP zone transfers that populate
the planet with a bunch of local caches.

Re: [9fans] mail problems..

[matt]

boyd, rounin wrote:

>>That seems to suggest that UDP works for billions of daily DNS requests.
>>
>>
>
>sure, and the reason it works is cos of the TCP zone transfers that populate
>the planet with a bunch of local caches.
>

sooo, that's exactly what mail servers are, local caches

an email address is a handle used to retrieve a list of local caches
from the MX records

but you know all this.

Your original argument was against the local cache pushing something to
the client over UDP because UDP doesn't scale.

> hmm,  i'd like to hear your design that would be reliable and scale to thousands of users.

Well, you've heard the design and Microsoft already successfully scale it to well over thousands of users all day every day.




Dan C said :
> A UDP packet that said, ``hey, you just got mail,'' would certainly scale to thousands of users.
> Unfortunately, no user agent software supports such a thing,


Sorry Dan, although I don't know which client I'm pretty sure we can draw conclusions from Exchange supporting the mechanism similar to the one described :


    http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B264035


    MORE INFORMATION

New mail notification messages are sent by means of UDP packets from the
server to the client. The ports used for this notification are set by
the client when the client logs on to the information store.

As part of the log on process to the information store, the client tells
the server the IP address and port where it expects to receive new mail
notification messages. This will be a UDP port in the 1024-65535 range.

When the server receives a mail message for a mailbox that a client is
logged on to, it opens a UDP port dynamically, and sends a packet to the
IP address and port registered by the client logged on to that mailbox.

Because the client picks a port at startup and the server does not
always use the same port when sending the notification, there is no way
to predict either the source or destination ports that this traffic will
use.

Re: [9fans] mail problems..

[boyd, rounin]

> an email address is a handle used to retrieve a list of local caches
> from the MX records
>
> but you know all this.

yes, i do.

> Your original argument was against the local cache pushing something to
> the client over UDP because UDP doesn't scale.

no it doesn't and my other point is it's not reliable, so you just bang out
packets until one finds its destination.  this, in a worst case scenario,
would flood the 'network'.

it 'works' by virtue of the fact that the problem has been reduced in scale.

'caches are multiplicative' i think rob said in his sam paper.

and there's NAT and firewalls, just for extra points etc, etc ...

Re: [9fans] mail problems..

[David Presotto]

It would be silly to only announce mail messages.  The daemon on the client
should generate plumbing messages.  We should have broadcast groups too.
I think we should call it .NET instant messenger.

Re: [9fans] mail problems..

[Richard Miller, miller]

>> By default, "periodically" means every 60 seconds, which is not a very
>> good choice if you have a dial-up connection or a busy mail server (or
>> both).  You can change this to N seconds by writing to /mail/fs/mbox/ctl
>> the (undocumented?) control message 'refresh N'.
>
> Is this too frequent or not frequent enough?  I usually do 15 seconds.

Too frequent with a dial-up connection - particularly in the UK where you
get charged by the minute for every call (even on the local exchange).

Too frequent for a server like pop3.demon.co.uk, which at busy times can
take two or three minutes just to login and STAT.

Anyway, my solution to the notifcation problem, now that I have broadband,
is to switch to a provider who can forward mail directly by SMTP.

-- Richard

Re: [9fans] mail problems..

[Apurva Mehta]

On Tue, 24 Jun 2003 20:13:03 -0400
"Russ Cox" <rsc@plan9.bell-labs.com> wrote:

> Every time you run the "mail" command, it will dial out just to
> see if there are new messages.  That might be the delay you are
> seeing.

How does it dial out automatically? I have not saved any connection
information anywhere (yet).  I connect using ip/ppp ..

> tail /sys/log/smtp and /sys/log/mail.  Probably an error occurred
> and they got dropped on the floor (the bounces bounced too).
> You can look at the queue in /mail/queue/$user.

The /sys/log/smtp file was empty. The /sys/log/mail file did list the
mails I had tried to send, but there was no error message associated
with any of them.

> Sure, but you also need to edit /mail/lib/remotemail to set the
> from domain there.  The headers file just affects the headers,
> not the smtp envelope.

I set fd=gmx.net in /mail/lib/remotemail .. Is this correct? Also, in
the/sys/log/mail file it continues to list the sender as 'apurva',
with no mention of the gmx.net domain. Personally, I feel that this
may be the reason why my emails are not reaching.

	- Apurva

Re: [9fans] mail problems..

[Russ Cox]

> upas/fs -f /pop/pop.gmx.net/my_user_name
>
> The first time I did that, I was asked for my password. It accepted it
> and the I got the term% prompt again.
>
> When I executed 'mail' from acme, it said that I had 0 messages. I
> know for a fact that there were messages on the server, why were they
> not downloaded?

This is because acme and your terminal are running
in different name spaces.  You need to start upas/fs
in your profile, before rio, to make it appear everywhere.
Alternately, you can use the apparently undocumented -s
option to upas/fs to post a service file:

	upas/fs -f -s /pop/pop.gmx.net/my_user_name

and then execute

	Local mount /srv/upasfs.$user /mail/fs

in acme to access it.

Russ

Re: [9fans] mail problems..

[Apurva Mehta]

On Tue, 24 Jun 2003 20:16:54 -0400
"Russ Cox" <rsc@plan9.bell-labs.com> wrote:

> This is because acme and your terminal are running
> in different name spaces.  You need to start upas/fs
> in your profile, before rio, to make it appear everywhere.
> Alternately, you can use the apparently undocumented -s
> option to upas/fs to post a service file:
>
> 	upas/fs -f -s /pop/pop.gmx.net/my_user_name
>
> and then execute
>
> 	Local mount /srv/upasfs.$user /mail/fs
>

When I execute the last line in acme, I get the error
/srv/upasfs.apurva file not found.. How should I create it?

	- Apurva