IIS and SMTP - Low Throughput of SMTP Service (3 messages x sec)

Author

Low Throughput of SMTP Service (3 messages x sec)

Roberto

2004-03-20, 2:37 pm

Hi,

My scenario is this:
a) Our software generate a lot of emails and put in the pickup
directory of the SMTP service of IIS5
b) The maximun size of the emails is 300kb, and the average is 50kb
c) We have 640kbps bandwidth
d) We need to deliver at least 100.000 emails for hour
e) I have a queue of 80.000+ files and the SMTP SVC is sending 3 mails
x sec, and is using 30kbs of bandwidth, which is driving me crazy.
f) Our machine is a Pentium III, 1 Ghz, 512 Megas RAM, Hard drive
SCSI, OS Windows 2000 (last SP installed). The processor is 10% busy,
the IIS have 70 threads, the memory have 50 MBs available. I mean the
machine is "easy going", but the queue is VERY large, and my hair is
falling down :-)
g) We dont need a POP3, only a SMTP Gateway, that sends and receive
the emails. We dont have users, that need to read the emails
received. These emails received we read from a folder and process
them in order to generate the response.
h) We are runing a service of List management. We receive the emails
from SMTP or our web interface, process the personalization and put in
the "pickup directory"
i) The actual configuration of the INETINFO/SMTPSVC is:
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\SMTPSVC\Parameters)
MsgHandleThreshold 1.000
MsgHandleAsyncThreshold 1.000
FileCacheMaxHandles 600
MaxDSNSize 2.048
AdditionalPoolThreadsPerProc 20
MaxPercentPoolThreads 90

INETINFO (HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)
ListenBackLog 25
DispatchEntries SMTPSVC
MaxPoolThreads 5
PoolThreadLimit 200
FileCacheMaxHandles 600
MaxCachedFileSize 4.000
MemCacheSize 100

SMTP Instance
Inbound conections 200
Inbound Time out 1
Outbound Conexiones 500
Outbound Time out 2
Conecctions for domain 5
Limit Messages size to (KB) 2.048
Limit Session Size (KB) 20.000
Limit number of messages per conexión 100

My specifics questions:
1) Am I missing a parameter that improve the Throughput of the SMTP
SVC?
2) Why is not using more resources the smtpsvc? (more cpu, more
memory, more threads, etc)
3) What i have to do in order to send more messages x sec?

Thanks a lot for your help!!!

Best Regards,

Roberto Matute

m.marien

2004-03-21, 9:34 am

"Roberto" <matuteroberto@hotmail.com> wrote in message
news:f21f1d7e.0403200953.20f398a7@posting.google.com...
> Hi,
>
> My scenario is this:
> a) Our software generate a lot of emails and put in the pickup
> directory of the SMTP service of IIS5
> b) The maximun size of the emails is 300kb, and the average is 50kb
> c) We have 640kbps bandwidth
> d) We need to deliver at least 100.000 emails for hour
> e) I have a queue of 80.000+ files and the SMTP SVC is sending 3 mails
> x sec, and is using 30kbs of bandwidth, which is driving me crazy.

That sounds about right. I get 40KBytes/sec upload on a 640kbits/s
connection. I assume your messages are 50kbits = 6.25 KBytes x 3 =
18.75KBytes/sec. You have to remember the overhead of name resolution,
communication with SMTP etc. As a guess, for 100,000 messages I think you
need a 640kbs x (100000/3600) / 3 = 6Mbs connection, plus your computer may
not be able to handle that load.

> f) Our machine is a Pentium III, 1 Ghz, 512 Megas RAM, Hard drive
> SCSI, OS Windows 2000 (last SP installed). The processor is 10% busy,
> the IIS have 70 threads, the memory have 50 MBs available. I mean the
> machine is "easy going", but the queue is VERY large, and my hair is
> falling down :-)
> g) We dont need a POP3, only a SMTP Gateway, that sends and receive
> the emails. We dont have users, that need to read the emails
> received. These emails received we read from a folder and process
> them in order to generate the response.
> h) We are runing a service of List management. We receive the emails
> from SMTP or our web interface, process the personalization and put in
> the "pickup directory"
> i) The actual configuration of the INETINFO/SMTPSVC is:
> (HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\SMTPSVC\Parameters)
> MsgHandleThreshold 1.000
> MsgHandleAsyncThreshold 1.000
> FileCacheMaxHandles 600
> MaxDSNSize 2.048
> AdditionalPoolThreadsPerProc 20
> MaxPercentPoolThreads 90
>
> INETINFO
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)[color
=darkred]
> ListenBackLog 25
> DispatchEntries SMTPSVC
> MaxPoolThreads 5
> PoolThreadLimit 200
> FileCacheMaxHandles 600
> MaxCachedFileSize 4.000
> MemCacheSize 100
>
> SMTP Instance
> Inbound conections 200
> Inbound Time out 1
> Outbound Conexiones 500
> Outbound Time out 2
> Conecctions for domain 5
> Limit Messages size to (KB) 2.048
> Limit Session Size (KB) 20.000
> Limit number of messages per conexión 100
>
> My specifics questions:
> 1) Am I missing a parameter that improve the Throughput of the SMTP
> SVC?
> 2) Why is not using more resources the smtpsvc? (more cpu, more
> memory, more threads, etc)
> 3) What i have to do in order to send more messages x sec?
>
> Thanks a lot for your help!!!
>
> Best Regards,
>
> Roberto Matute[/color]

Roberto

2004-03-21, 5:34 pm

"m.marien" <mm AT RiverCityCanada DOT com> wrote in message news:<105r71ibif6052b@corp.supernews.com>...
> "Roberto" <matuteroberto@hotmail.com> wrote in message
> news:f21f1d7e.0403200953.20f398a7@posting.google.com...
>
> That sounds about right. I get 40KBytes/sec upload on a 640kbits/s
> connection. I assume your messages are 50kbits = 6.25 KBytes x 3 =
> 18.75KBytes/sec. You have to remember the overhead of name resolution,
> communication with SMTP etc. As a guess, for 100,000 messages I think you
> need a 640kbs x (100000/3600) / 3 = 6Mbs connection, plus your computer may
> not be able to handle that load.

Thanks a lot for your help!!!
Our bandwidth is 640 kbytes per sec; I mean the SMTP svc is using only
5% of our bandwith. This is what is driving me crazy; a really BIG
queue, and the smtp not using the bandwith.

I was playing with the parameters of the SMTP Svc and inetinfo in
order to increase the resources they use, but I can't make the
Throughput increase.

Best Regards,

Roberto

[color=darkred]
> (HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)

m.marien

2004-03-21, 7:34 pm

"Roberto" <matuteroberto@hotmail.com> wrote in message
news:f21f1d7e.0403211359.2e268657@posting.google.com...
> "m.marien" <mm AT RiverCityCanada DOT com> wrote in message
news:<105r71ibif6052b@corp.supernews.com>...
you[color=darkred]
may[color=darkred]
>
> Thanks a lot for your help!!!
> Our bandwidth is 640 kbytes per sec; I mean the SMTP svc is using only
> 5% of our bandwith. This is what is driving me crazy; a really BIG
> queue, and the smtp not using the bandwith.
>
> I was playing with the parameters of the SMTP Svc and inetinfo in
> order to increase the resources they use, but I can't make the
> Throughput increase.
>
> Best Regards,
>
> Roberto
>

Perhaps I am wrong. However, the way I understand it, a T1 line is 1.5Mbps.
The small b signifies bits rather than bytes which I think is normal for
measuring bandwidth. 640Kbps is a fractional T1 or perhaps an ADSL
connection. I have an ADSL with 3.2Mbps download and 640Kbps upload. My
average measured upload is 40KBytes per second. That is about half of what I
would expect (640Kbps / 8bits = 80 KBytes per second). However, there are
probably check bits, packet addressing and other communication overhead.

As a check, I rarely see better than 220KBytes per second download. So
3.2Mbps / 220 (download ratio) = ~15 * 40 (upload speed) = 600 which is
close to my upload speed of 640Kbps.

I could be wrong, but I think you are at your maximum bandwidth for your
connection. You need better than a 4 x T1 connection to send 100000 messages
per hour.

I think our ISP installed a few million dollars worth of equipment to handle
that volume.
[color=darkred]
>
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\SMTPSVC\Parameters)[color=
darkred]
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)[color
=darkred]

Roberto

2004-03-22, 1:35 pm

"m.marien" <mm AT RiverCityCanada DOT com> wrote in message news:<105s9ol6dqd0q5b@corp.supernews.com>...
> "Roberto" <matuteroberto@hotmail.com> wrote in message
> news:f21f1d7e.0403211359.2e268657@posting.google.com...
> news:<105r71ibif6052b@corp.supernews.com>...
> you
> may
>
> Perhaps I am wrong. However, the way I understand it, a T1 line is 1.5Mbps.
> The small b signifies bits rather than bytes which I think is normal for
> measuring bandwidth. 640Kbps is a fractional T1 or perhaps an ADSL
> connection. I have an ADSL with 3.2Mbps download and 640Kbps upload. My
> average measured upload is 40KBytes per second. That is about half of what I
> would expect (640Kbps / 8bits = 80 KBytes per second). However, there are
> probably check bits, packet addressing and other communication overhead.
>
> As a check, I rarely see better than 220KBytes per second download. So
> 3.2Mbps / 220 (download ratio) = ~15 * 40 (upload speed) = 600 which is
> close to my upload speed of 640Kbps.
>
> I could be wrong, but I think you are at your maximum bandwidth for your
> connection. You need better than a 4 x T1 connection to send 100000 messages
> per hour.
>
> I think our ISP installed a few million dollars worth of equipment to handle
> that volume.

Marien,

The important fact here is the smpt service is using only a 5% of our
bandwidth. I mean, in the stats from our DataCenter we are using
only a 5% of our total bandwith. What I want is to use ALL the
bandwith (or at least more than 50%). Is not a problem of units, is a
problem of the % of the bandwith SMTP Svc is using.

I was playing with all the parameters that put in my first post, but I
cant figure out how to improve the Throughput of the SMTP svc.

My questions are:
1) Am I missing a parameter that improve the Throughput of the SMTP
SVC?
2) Why is not using more resources the smtpsvc? (more cpu, more
memory, more threads, etc)
3) What i have to do in order to send more messages x sec?

Thanks for the help,

Roberto

[color=darkred]
> (HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\SMTPSVC\Parameters)
> (HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)

Jason McClellan

2004-03-28, 2:34 am

It sounds like a typical mix-up of 'bits' and 'bytes'

Your internet connection is 640 kiloBITS per second. Your mail server is
sending 30 kiloBYTES per second, which equates to roughly 300 kilobits/sec.
You cannot directly compare the numbers without converting one! Your
bandwidth utilization is definately a little low, but the other guy's right,
you have to add name resolution and such, so it's not unreasonable. Also,
if your resolving DNS server is slow to respond to your queries, it may
introduce delays for each message sent as well.

Remember the distinction between Kb/sec and KB/sec! It's at least ten-fold.
You need a bigger internet connection!

Of course, another option is to stop spamming... who else needs to send
100,000 emails per hour? <insert "can-of-worms opening" sound here>

Jason

"Roberto" <matuteroberto@hotmail.com> wrote in message
news:f21f1d7e.0403221021.385a8f28@posting.google.com...
> "m.marien" <mm AT RiverCityCanada DOT com> wrote in message
news:<105s9ol6dqd0q5b@corp.supernews.com>...[color=darkred]
50kb[color=darkred]
mails[color=darkred]
resolution,[color=darkred]
think[color=darkred]
computer[color=darkred]
1.5Mbps.[color=darkred]
what I[color=darkred]
are[color=darkred]
messages[color=darkred]
handle[color=darkred]
>
> Marien,
>
> The important fact here is the smpt service is using only a 5% of our
> bandwidth. I mean, in the stats from our DataCenter we are using
> only a 5% of our total bandwith. What I want is to use ALL the
> bandwith (or at least more than 50%). Is not a problem of units, is a
> problem of the % of the bandwith SMTP Svc is using.
>
> I was playing with all the parameters that put in my first post, but I
> cant figure out how to improve the Throughput of the SMTP svc.
>
> My questions are:
> 1) Am I missing a parameter that improve the Throughput of the SMTP
> SVC?
> 2) Why is not using more resources the smtpsvc? (more cpu, more
> memory, more threads, etc)
> 3) What i have to do in order to send more messages x sec?
>
>
> Thanks for the help,
>
> Roberto
>
>
>
busy,[color=darkred]
the[color=darkred]
is[color=darkred]
receive[color=darkred]
emails[color=darkred]
put in[color=darkred]
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\SMTPSVC\Parameters)[color=
darkred]
(HKEY_LOCAL_MACHINE\SYSTEM\CurrentContro
lSet\Services\InetInfo\Parameters)[color
=darkred]
SMTP[color=darkred]