I've been having trouble for the last 24 hrs or maybe a bit more with log
uploads failing.  The FTP either fails to connect, or it does connect and
the upload begins and then fails after a small percentage done.  Uploads are
scheduled every 6 hours.  Yesterday afternoon I tried renaming the log files
from a couple failures and triggering the upload manually, and it also
failed

An upload started a few mins ago, at 12:05 PM.  It progressed almost to
completion, and then ended with a reported failure from WS_FTP.

Glenn Z.
WCNet



----- Original Message ----- 
From: "Pete McNeil" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, March 20, 2004 1:13 AM
Subject: Re: [sniffer] Define Persistent sniffer.


> At 09:50 PM 3/19/2004, you wrote:
> >Pete,
> >        I follow this forum pretty well, however, having been out this
> > week on business it seems I have lost alot with this new feature set.
If
> > you don't mind, could you define Persistent Sniffer?  We average well
> > over a million emails a day between two servers, what impact might I see
> > on our server if I run this?  What is the recommended settings?  Thanks
> > for the aid.
>
> (Seems I'm in the "book writing" mode this evening... sorry for the
bandwidth)
>
> ____________________
> Performance Metrics:
>
> Our NT4/SP6a test bed, running IMail/Declude/Sniffer in persistent mode.
> P2/450, 2x 5400rpm IDE drives, mirrored, 256M Ram (No giggles please -
This
> is an intentionally underpowered server - how better to stress test a
> program like Sniffer?).
>
> Sniffer in persistent mode on this box is able to process 120k msgs /
month
> without issue. Logs show that each message on average now takes about
100ms
> total. Typical values are 20ms queue, 40ms scan though obviously some
> messages take longer and occasionally longer queue times do creep in.
>
> Prior to testing the persistent version of Sniffer, message scan times
> varied wildly but averaged about 300ms per message with some messages
> taking 3-5 seconds while waiting for I/O and other processes (Web Mail,
> IMAP, etc...). In fact, I intentionally waited until the CPU was at 100%
> (green line 100%, red line 50%+) before starting the service to see how
the
> creatures would handle the transition under heavy stress - The CPU dropped
> so much that at first I thought I had broken something (one of those
"oops"
> moments).
>
> The CPU now rests on the floor more often than not and generally runs
peaks
> to about 50% unless something odd is going on - such as a defrag run.
>
> YMMV - the above data is based on a very narrow data sample and only
> loosely calculated - and some of it is anecdotal. However most reports
from
> the field seem to support the general scale of improvement.
>
> On the back of the envelope I can calculate something like: 1 million per
> day is probably on the order of 125000 (1M/8hours) during a peak hour.
> 125000/3600 = about 35 per second. If message sniffer can scan about 10
per
> second on an overloaded p2/450, then on a 2.4ghz machine with plenty of
> memory we might expect at least a linear improvement - approximately 5x,
> but we will say 4x to be safe - 40/sec covers 35/sec so we have our
million
> based on these assumptions.
>
> IO not withstandng I would expect a persistent server version of Sniffer
on
> a well provisioned server with a 2.4ghz processor to handle 1 million per
> day _IF_ that's all it had to do... since there's always more to do and
> this would be a maximum load scenario, dividing this across two servers
> should work nicely - though it would probably be time to start considering
> a third server.
>
> Then again, you are probably not running generic single processor servers
> if you are handling 1 million messages per day ;-)
>
> ___________
> Definition:
>
> Probably the simplest definition of "Persistent Sniffer" as you put it is
a
> "lightweight daemon". It can't actually be launched as a daemon/service on

> it's own, and it is still compatible with the self-organizing-automata
> version of Sniffer, but it offers many of the performance savings of a
> daemon/service - along with some added redundancy and flexibility. For
> example, if the persistent server instance of Sniffer fails, then the
other
> instances simply return to their normal peer-server mode of operation so
> there is a drop in performance, but not a loss of service.
>
> ____________
> More Detail:
>
> Versions of Message Sniffer prior to 2-2 would always load the rule-base
> each time a message was to be scanned. Specifically, each instance of
> Message Sniffer was isolated and did the job itself. Up to 90% of the
> processing time typically required was bound in loading the rule-base
file.
> On our NT test bed, for example, we would regularly see queue/scan times
on
> the order of 1000/10, though more commonly 360/60 at the time when we
> developed version 2-2.
>
> Beginning with Version 2-2, we implemented a "cellular peer-server"
> technology with Message Sniffer. This technology allows instances of
> Message Sniffer running on the same server to interact and self-organize,
> much like a colony of insects. In simplest terms there are two modes that
> Sniffer 2-2 can be in: "server" or "client". Whenever an instance finds no
> other "server" instances it will elect to be a "server" and will load the
> rule-base and process messages for "client" instances for some period of
> time, or until there are no other "client" instances available. This
> significantly reduces the number of times the rule-base is loaded for a
> given number of messages and allows Sniffer to dynamically adapt to the
> loads on a given server.
>
> Beginning with the current beta (which will become version 2-3), we can
> force a sniffer instance to become a "persistent server". In simplest
> terms, we trick the creature into electing a server mode, and then further
> trick it into remaining alive for long periods - even if there are no
> clients to serve. The result is that all other instances of Sniffer
> _should_ elect to be clients - so there is only one instance that has
> loaded the rule-base and that instance only reloads the rule-base
> infrequently (about every 10 minutes unless there is an unusual collision
> event with other Sniffer instances).
>
> ________
> Effects:
>
> In general you should see a dramatic drop in processing times for any
> single message and a commensurate drop in I/O & CPU utilization by
Sniffer.
> One instance will be "nailed up" as a server, and all other instances will
> normally elect to be clients.
>
> ____________________
> Additional Comments:
>
> Note that additional software is required to run a persistent instance of
> sniffer as a service on the winx platform - but there are a number of
> utilities for this and they all appear to be stable and fairly simple to
use.
>
> Note also that Sniffer still does not depend on any network resources and
> therefore does not represent any additional networking load, nor any
> potential network security risk.
>
> This will change eventually as we do have plans to develop true
> Daemon/Service versions of Sniffer - but in the short/medium term we are
> putting our development resources into additional features and performance
> enhancements.
>
> Currently Message Sniffer uses a single code base that compiles on all
> platforms without modifications and a vanishingly small amount of #ifdef
> style code switches - primarily for dealing with the Sleep() function(s).
> We would like to keep it this way for as long as possible - there are many
> benefits.
>
> Hope this helps,
> Thanks!
> _M
>
>
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