Re: about realtime system

2014-08-24 Thread Nico Kadel-Garcia
On Sat, Aug 23, 2014 at 11:20 PM, Brandon Vincent
brandon.vinc...@asu.edu wrote:
 On Fri, Aug 22, 2014 at 9:41 AM, llwa...@gmail.com wrote:
 Does it really make difference in timing control comparing to non-realtime
 kernel? Thanks.

 Whether or not you need a RTOS depends on your specific needs. Since
 you're working with LabVIEW, I would check out their white paper on
 the subject.

 http://www.ni.com/white-paper/14238/en/

I assume you're running real hardware, instead of virtual systems?
I've seen people try to run real-time systems in virtuaalized,
CentOS based VMware systems, and the results for extremely low latency
operations were not encouraging. I also spent a lot of time with that
with CentOS 5 making sure the hosted partitions were 4096 byte block
aligned, which made a *big* difference with NetApp backend disk image
storage.

 I don't have NI's realtime system but I am looking for a free linux OS which
 supports realtime kernel. So I wonder does anyone have experience in
 this on scientific linux? Does it support realtime kernel?

 NI Linux Real-Time is based off of the PREEMPT_RT patch set which you
 can find on the kernel.org Wiki.

 https://rt.wiki.kernel.org/index.php/CONFIG_PREEMPT_RT_Patch

 I've never compiled an EL kernel with the patch, but there is no
 reason why it should not be possible.

 Brandon Vincent

If you go this route, do look into creating kernel RPM's with the
mock toolkit and with patches applied as part of the SRPM. It's
extra work to start with, but lets you manage the kernels and report
dependencies more effectively.


Re: about realtime system

2014-08-24 Thread John Lauro
Why spread FUD about Vmware.  Anyways, to hear what they say on the subject:
http://www.vmware.com/files/pdf/techpaper/latency-sensitive-perf-vsphere55.pdf

Anyways, KVM will not handle latency any better than Vmware.

- Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: Brandon Vincent brandon.vinc...@asu.edu, llwa...@gmail.com, 
 SCIENTIFIC-LINUX-USERS@FNAL.GOV
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 12:26:17 PM
 Subject: Re: about realtime system
 
 Wow I don't know how VMware got mentioned in this string but VMware
 is
 not capable of real time operation and if you ask the senior
 engineers
 at VMware they will tell you they don't want you even trying it on
 their product because they know it wont work. The reason is VMware
 plays games with the clock on the VM so the clocks can never be 100%
 accurate.
 It should be possible to do real time in KVM assuming you don't
 overbook your CPU Cores or RAM. Apparently Red Hat has been doing
 VM's
 with microsecond accurate clocks with PTP running on the
 visualization


Re: about realtime system

2014-08-24 Thread Nico Kadel-Garcia
On Sun, Aug 24, 2014 at 12:57 PM, John Lauro
john.la...@covenanteyes.com wrote:
 Why spread FUD about Vmware.  Anyways, to hear what they say on the subject:
 http://www.vmware.com/files/pdf/techpaper/latency-sensitive-perf-vsphere55.pdf

 Anyways, KVM will not handle latency any better than Vmware.

 - Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: Brandon Vincent brandon.vinc...@asu.edu, llwa...@gmail.com, 
 SCIENTIFIC-LINUX-USERS@FNAL.GOV
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 12:26:17 PM
 Subject: Re: about realtime system

 Wow I don't know how VMware got mentioned in this string but VMware
 is
 not capable of real time operation and if you ask the senior
 engineers
 at VMware they will tell you they don't want you even trying it on
 their product because they know it wont work. The reason is VMware
 plays games with the clock on the VM so the clocks can never be 100%
 accurate.
 It should be possible to do real time in KVM assuming you don't
 overbook your CPU Cores or RAM. Apparently Red Hat has been doing
 VM's
 with microsecond accurate clocks with PTP running on the
 visualization


I mentioned that I hope they were using real servers, not VM's. I'd
had people try to run real-time systems in virtualization,
specifically with VMware, and it wasn't workable for their needs.

Also, high precision is not the same as low latency, although both
are often grouped together for real-time operations. I'm curious if
Paul needs both.


Re: about realtime system

2014-08-24 Thread Brandon Vincent
On Sun, Aug 24, 2014 at 9:26 AM, Paul Robert Marino prmari...@gmail.com wrote:
 That said I've run hundreds of mission critical systems many accurate to 
 within 5
 milliseconds on the standard kernel with proper tuning and a stripped
 down OS install for nearly a decade and Ive never had an issue.

The standard Linux kernel shipped by most distributions is actually
quite effective in applications that require millisecond level
scheduling precision. Paul's experience confirms this.

If the need for smaller interrupt and scheduling latency arises, the
stock kernel source allows you to generate a soft real-time kernel by
choosing the Preemptible Kernel (PREEMPTDESKTOP) during kernel
configuration and compilation.

What the standard kernel source doesn't provide is reliable and
consistent sub-millisecond scheduling. Applying the PREEMPT_RT patch
generates what can for the most part be considered a hard RTOS kernel.

For the most part in 99% of applications the standard kernel will
suffice. Without knowing what Lee's application is, it is impossible
to determine if he really needs a soft or hard real-time kernel.

Brandon Vincent


Re: about realtime system

2014-08-24 Thread Paul Robert Marino
Nico
Depending on the role of the particular system and or which company I
was working for at the time I've need one the other or both.
In my current role in the broadcast industry precision with
predictable latency is more important for most of my systems.
That said when I worked in the financial industry it changed based on
what part of the industy I was working for.
The stock exchanges I've worked for cared about precision because it
was more important to them to make sure every one had the same latency
and our logging was accurate for audit purposes.
When I used to work for a managed systems vender for hedge funds they
were all about low latency because the faster they got data in and out
of the exchanges often determined if they had an edge over their
competitors or not. quite literally an extra millisecond could cost
them millions of dollars a second due to the nature of high frequency
trading.

Generally I don't think of real time kernels when I am thinking about
low latency because oftent they increase the latency when dealing with
multiple operations. however the reverse can true if you only have a
box doing one specific task only but that rarely is the case.

By the way one of those stock exchanges is where the VMware engineers
told us never to use their product in production. In fact we had huge
problems with VMware in our development environments because some of
our applications would actually detect the clock instability in the
VMware clocks and would shut themselves down rather than have
inaccurate audit logs. as a result we found we had trouble even using
it in our development environments.

By the way Red hat only told me recently about guaranteeing the
microsecond precision of the clocks in KVM on RHEV and said they have
been doing it in financial for over a year. there are conditions
though such as you need to turn off support for overbooking the CPU
cores. last I checked VMware still says do not use their product
anywhere where you need millisecond accurate clocks.

Further more I dont know about that statement Anyways, KVM will not
handle latency any better than Vmware. the article you pointed out
talks about VCPU's going in and out of halted states, which is normal
and completely expected in VMware because they always assume you are
going to overbook your CPU cores. there is a slight difference when
you talk about KVM in paravirtualized mode with overbooking disabled
it directly maps the CPU cores the the VM so as long as you don't have
power management enabled the CPU's are always operating at full speed
further more you can directly map PCIe bus address to the VM
(essentially assigning a card on your bus directly to the VM to be
completely managed by its kernel) to reduce latency in other ways to
hardware if you need too.

On Sun, Aug 24, 2014 at 2:02 PM, Nico Kadel-Garcia nka...@gmail.com wrote:
 On Sun, Aug 24, 2014 at 12:57 PM, John Lauro
 john.la...@covenanteyes.com wrote:
 Why spread FUD about Vmware.  Anyways, to hear what they say on the subject:
 http://www.vmware.com/files/pdf/techpaper/latency-sensitive-perf-vsphere55.pdf

 Anyways, KVM will not handle latency any better than Vmware.

 - Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: Brandon Vincent brandon.vinc...@asu.edu, llwa...@gmail.com, 
 SCIENTIFIC-LINUX-USERS@FNAL.GOV
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 12:26:17 PM
 Subject: Re: about realtime system

 Wow I don't know how VMware got mentioned in this string but VMware
 is
 not capable of real time operation and if you ask the senior
 engineers
 at VMware they will tell you they don't want you even trying it on
 their product because they know it wont work. The reason is VMware
 plays games with the clock on the VM so the clocks can never be 100%
 accurate.
 It should be possible to do real time in KVM assuming you don't
 overbook your CPU Cores or RAM. Apparently Red Hat has been doing
 VM's
 with microsecond accurate clocks with PTP running on the
 visualization


 I mentioned that I hope they were using real servers, not VM's. I'd
 had people try to run real-time systems in virtualization,
 specifically with VMware, and it wasn't workable for their needs.

 Also, high precision is not the same as low latency, although both
 are often grouped together for real-time operations. I'm curious if
 Paul needs both.


Re: about realtime system

2014-08-24 Thread Paul Robert Marino
PS. That last paragraph was intended to respond to John not Nico.

On Sun, Aug 24, 2014 at 3:27 PM, Paul Robert Marino prmari...@gmail.com wrote:
 Nico
 Depending on the role of the particular system and or which company I
 was working for at the time I've need one the other or both.
 In my current role in the broadcast industry precision with
 predictable latency is more important for most of my systems.
 That said when I worked in the financial industry it changed based on
 what part of the industy I was working for.
 The stock exchanges I've worked for cared about precision because it
 was more important to them to make sure every one had the same latency
 and our logging was accurate for audit purposes.
 When I used to work for a managed systems vender for hedge funds they
 were all about low latency because the faster they got data in and out
 of the exchanges often determined if they had an edge over their
 competitors or not. quite literally an extra millisecond could cost
 them millions of dollars a second due to the nature of high frequency
 trading.

 Generally I don't think of real time kernels when I am thinking about
 low latency because oftent they increase the latency when dealing with
 multiple operations. however the reverse can true if you only have a
 box doing one specific task only but that rarely is the case.

 By the way one of those stock exchanges is where the VMware engineers
 told us never to use their product in production. In fact we had huge
 problems with VMware in our development environments because some of
 our applications would actually detect the clock instability in the
 VMware clocks and would shut themselves down rather than have
 inaccurate audit logs. as a result we found we had trouble even using
 it in our development environments.

 By the way Red hat only told me recently about guaranteeing the
 microsecond precision of the clocks in KVM on RHEV and said they have
 been doing it in financial for over a year. there are conditions
 though such as you need to turn off support for overbooking the CPU
 cores. last I checked VMware still says do not use their product
 anywhere where you need millisecond accurate clocks.

 Further more I dont know about that statement Anyways, KVM will not
 handle latency any better than Vmware. the article you pointed out
 talks about VCPU's going in and out of halted states, which is normal
 and completely expected in VMware because they always assume you are
 going to overbook your CPU cores. there is a slight difference when
 you talk about KVM in paravirtualized mode with overbooking disabled
 it directly maps the CPU cores the the VM so as long as you don't have
 power management enabled the CPU's are always operating at full speed
 further more you can directly map PCIe bus address to the VM
 (essentially assigning a card on your bus directly to the VM to be
 completely managed by its kernel) to reduce latency in other ways to
 hardware if you need too.

 On Sun, Aug 24, 2014 at 2:02 PM, Nico Kadel-Garcia nka...@gmail.com wrote:
 On Sun, Aug 24, 2014 at 12:57 PM, John Lauro
 john.la...@covenanteyes.com wrote:
 Why spread FUD about Vmware.  Anyways, to hear what they say on the subject:
 http://www.vmware.com/files/pdf/techpaper/latency-sensitive-perf-vsphere55.pdf

 Anyways, KVM will not handle latency any better than Vmware.

 - Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: Brandon Vincent brandon.vinc...@asu.edu, llwa...@gmail.com, 
 SCIENTIFIC-LINUX-USERS@FNAL.GOV
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 12:26:17 PM
 Subject: Re: about realtime system

 Wow I don't know how VMware got mentioned in this string but VMware
 is
 not capable of real time operation and if you ask the senior
 engineers
 at VMware they will tell you they don't want you even trying it on
 their product because they know it wont work. The reason is VMware
 plays games with the clock on the VM so the clocks can never be 100%
 accurate.
 It should be possible to do real time in KVM assuming you don't
 overbook your CPU Cores or RAM. Apparently Red Hat has been doing
 VM's
 with microsecond accurate clocks with PTP running on the
 visualization


 I mentioned that I hope they were using real servers, not VM's. I'd
 had people try to run real-time systems in virtualization,
 specifically with VMware, and it wasn't workable for their needs.

 Also, high precision is not the same as low latency, although both
 are often grouped together for real-time operations. I'm curious if
 Paul needs both.


Re: about realtime system

2014-08-24 Thread John Lauro
The recommendation changed with 5.5.  
http://blogs.vmware.com/performance/2013/09/deploying-extremely-latency-sensitive-applications-in-vmware-vsphere-5-5.html

... However, performance demands of latency-sensitive applications with very 
low latency requirements such as distributed in-memory data management, stock 
trading, and high-performance computing have long been thought to be 
incompatible with virtualization.
vSphere 5.5 includes a new feature for setting latency sensitivity in order to 
support virtual machines with strict latency requirements.


- Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: John Lauro john.la...@covenanteyes.com, Brandon Vincent 
 brandon.vinc...@asu.edu, Lee Kin
 llwa...@gmail.com, SCIENTIFIC-LINUX-USERS@FNAL.GOV 
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 3:27:39 PM
 Subject: Re: about realtime system
...
 By the way one of those stock exchanges is where the VMware engineers
 told us never to use their product in production. In fact we had huge
 problems with VMware in our development environments because some of
 our applications would actually detect the clock instability in the
 VMware clocks and would shut themselves down rather than have
 inaccurate audit logs. as a result we found we had trouble even using
 it in our development environments.


Re: about realtime system

2014-08-24 Thread Paul Robert Marino
John
reread the first and third paragraph of my previous email.
Trading firms care about low latency but never cared about the
accuracy millisecond of the clocks. Sock exchanges on the other hand
want predictable latency not necessarily low latency but absolutely
require millisecond and if possible microsecond accurate clocks.
The reason for this is trading funds are worried about getting quotes,
bids, executions, etc. to the exchanges gateways as fast as possible;
however the exchange has to be able to prove to both the member firms
and the regulators that everyone is treated fairly once they put an
order into the gateway.

While yes VMware says under very specific configurations with 3/4ths
of their features disabled and special network cards which offload
their virtual switch's work VMware can handle low latency, but they
still can not handle clocks accurate to the millisecond and certain
cant handle it to the microsecond.
Furthermore I find this article highly suspect because its talking
about reducing the latency overhead in their visualization stack to
the point where it becomes less noticeable not necessarily true low
latency. This makes it acceptable for small hedge funds which have
staff and equipment budget constraints, but not really good enough for
the big boys if they are smart. I would advise you to be careful with
VMwares technical marketing docs and blogs in this area because the
sale people will tell you anything to get you to buy it, their high
level engineers will actually tell you the truth if they know what you
are using it for. In true real time and high precision situations
their senior engineers will tell the sales department to wave you off
of using their product if your employer is a big enough name for for
the real senior engineers (not sales engineers) to look at your
design prior to sale.

If you dive deep into that article it say's you need
   1) very specific hardware support specifically network cards
   2) you need to turn off vmotion and all of the other fault tolerance features
   3) you need to have very specific features turned on
   4) It makes strongly implied suggestion but doesn't state flat out
that for best performance you need to align the number of cores you
assign to the layout of the cache in your CPU so you don't get
multiple VM's sharing CPU cache even if that means assigning more
VCPUs than you need.
   5) a separate physical network card for each VM
   6) disable memory over committing (Same as KVM)
   7) disable CPU over committing (Same as KVM)

Even with that all of that you still do not have a 10 microsecond
latency jitter in the network stack, and the accuracy of the clocks
are still not guaranteed to the millisecond. In no place in that
article or the blog is clock accuracy mentioned at all.
All they are talking about is better response time latency not real precision.




On Sun, Aug 24, 2014 at 3:46 PM, John Lauro john.la...@covenanteyes.com wrote:
 The recommendation changed with 5.5.
 http://blogs.vmware.com/performance/2013/09/deploying-extremely-latency-sensitive-applications-in-vmware-vsphere-5-5.html

 ... However, performance demands of latency-sensitive applications with very 
 low latency requirements such as distributed in-memory data management, stock 
 trading, and high-performance computing have long been thought to be 
 incompatible with virtualization.
 vSphere 5.5 includes a new feature for setting latency sensitivity in order 
 to support virtual machines with strict latency requirements.


 - Original Message -
 From: Paul Robert Marino prmari...@gmail.com
 To: Nico Kadel-Garcia nka...@gmail.com
 Cc: John Lauro john.la...@covenanteyes.com, Brandon Vincent 
 brandon.vinc...@asu.edu, Lee Kin
 llwa...@gmail.com, SCIENTIFIC-LINUX-USERS@FNAL.GOV 
 scientific-linux-users@fnal.gov
 Sent: Sunday, August 24, 2014 3:27:39 PM
 Subject: Re: about realtime system
 ...
 By the way one of those stock exchanges is where the VMware engineers
 told us never to use their product in production. In fact we had huge
 problems with VMware in our development environments because some of
 our applications would actually detect the clock instability in the
 VMware clocks and would shut themselves down rather than have
 inaccurate audit logs. as a result we found we had trouble even using
 it in our development environments.


Re: gnome-disk-utility

2014-08-24 Thread ToddAndMargo

On 08/24/2014 04:00 PM, Vladimir Mosgalin wrote:

Hi ToddAndMargo!

  On 2014.08.24 at 13:30:43 -0700, ToddAndMargo wrote next:


I noticed on the 6.2 live cd (might have been dvd) that there
was a tool called gnome-disk-utility.  It flagged a
failing hard drive, which was much appreciated.

So I went looking for it on my native 6.5 to use it there too.
Yum says I have it installed.

I can't find it for my life.

How do I use this thing the way they did in the Live CD?


Yes it has quite funny name.

$ rpm -ql gnome-disk-utility|grep bin
/usr/bin/palimpsest


Hi Vladimir,

Yup.  That is it.  Thank you!

Also, it has no man or info page.

How do I get it up in my task bar, as does the Live CD?

Many thanks,
-T


Re: about realtime system

2014-08-24 Thread jdow

The stock exchange could remove most of the problem, meaning high
frequency trades, by placing a purely random 0 to 1 second latency
on all incoming data and all outgoing data. The high frequency trading
reads to me as just another means of skimming now that they're not
allowed to round down fractional pennies and pocket the change. It's
time to give mere mortals some practical access to the exchanges. And
this interest in microsecond clocks would simply vanish from the
exchanges.

On a different point, the word I can find is that the free version of
VMWare does not support this high latency sensitivity setting.

{o.o}   Joanne, Just sayin'

On 2014-08-24 13:42, Paul Robert Marino wrote:

John
reread the first and third paragraph of my previous email.
Trading firms care about low latency but never cared about the
accuracy millisecond of the clocks. Sock exchanges on the other hand
want predictable latency not necessarily low latency but absolutely
require millisecond and if possible microsecond accurate clocks.
The reason for this is trading funds are worried about getting quotes,
bids, executions, etc. to the exchanges gateways as fast as possible;
however the exchange has to be able to prove to both the member firms
and the regulators that everyone is treated fairly once they put an
order into the gateway.

While yes VMware says under very specific configurations with 3/4ths
of their features disabled and special network cards which offload
their virtual switch's work VMware can handle low latency, but they
still can not handle clocks accurate to the millisecond and certain
cant handle it to the microsecond.
Furthermore I find this article highly suspect because its talking
about reducing the latency overhead in their visualization stack to
the point where it becomes less noticeable not necessarily true low
latency. This makes it acceptable for small hedge funds which have
staff and equipment budget constraints, but not really good enough for
the big boys if they are smart. I would advise you to be careful with
VMwares technical marketing docs and blogs in this area because the
sale people will tell you anything to get you to buy it, their high
level engineers will actually tell you the truth if they know what you
are using it for. In true real time and high precision situations
their senior engineers will tell the sales department to wave you off
of using their product if your employer is a big enough name for for
the real senior engineers (not sales engineers) to look at your
design prior to sale.

If you dive deep into that article it say's you need
1) very specific hardware support specifically network cards
2) you need to turn off vmotion and all of the other fault tolerance 
features
3) you need to have very specific features turned on
4) It makes strongly implied suggestion but doesn't state flat out
that for best performance you need to align the number of cores you
assign to the layout of the cache in your CPU so you don't get
multiple VM's sharing CPU cache even if that means assigning more
VCPUs than you need.
5) a separate physical network card for each VM
6) disable memory over committing (Same as KVM)
7) disable CPU over committing (Same as KVM)

Even with that all of that you still do not have a 10 microsecond
latency jitter in the network stack, and the accuracy of the clocks
are still not guaranteed to the millisecond. In no place in that
article or the blog is clock accuracy mentioned at all.
All they are talking about is better response time latency not real precision.




On Sun, Aug 24, 2014 at 3:46 PM, John Lauro john.la...@covenanteyes.com wrote:

The recommendation changed with 5.5.
http://blogs.vmware.com/performance/2013/09/deploying-extremely-latency-sensitive-applications-in-vmware-vsphere-5-5.html

... However, performance demands of latency-sensitive applications with very 
low latency requirements such as distributed in-memory data management, stock 
trading, and high-performance computing have long been thought to be incompatible 
with virtualization.
vSphere 5.5 includes a new feature for setting latency sensitivity in order to 
support virtual machines with strict latency requirements.


- Original Message -

From: Paul Robert Marino prmari...@gmail.com
To: Nico Kadel-Garcia nka...@gmail.com
Cc: John Lauro john.la...@covenanteyes.com, Brandon Vincent 
brandon.vinc...@asu.edu, Lee Kin
llwa...@gmail.com, SCIENTIFIC-LINUX-USERS@FNAL.GOV 
scientific-linux-users@fnal.gov
Sent: Sunday, August 24, 2014 3:27:39 PM
Subject: Re: about realtime system

...

By the way one of those stock exchanges is where the VMware engineers
told us never to use their product in production. In fact we had huge
problems with VMware in our development environments because some of
our applications would actually detect the clock instability in the
VMware clocks and would shut themselves down rather than have
inaccurate audit logs. as a result we found we had 

Re: about realtime system

2014-08-24 Thread Nico Kadel-Garcia
On Sun, Aug 24, 2014 at 3:27 PM, Paul Robert Marino prmari...@gmail.com wrote:
 Nico
 Depending on the role of the particular system and or which company I
 was working for at the time I've need one the other or both.
 In my current role in the broadcast industry precision with
 predictable latency is more important for most of my systems.
 That said when I worked in the financial industry it changed based on
 what part of the industy I was working for.

I... need to step out of some parts of this disussion, due to NDA's.

 Further more I dont know about that statement Anyways, KVM will not
 handle latency any better than Vmware. the article you pointed out
 talks about VCPU's going in and out of halted states, which is normal

I'm afraid that wasn't me. I just expressed my hope that the original
poster was using real hardware, not virtualization, due to my poor
experience and the architectural constraints of virtualization.

 and completely expected in VMware because they always assume you are
 going to overbook your CPU cores. there is a slight difference when
 you talk about KVM in paravirtualized mode with overbooking disabled
 it directly maps the CPU cores the the VM so as long as you don't have
 power management enabled the CPU's are always operating at full speed
 further more you can directly map PCIe bus address to the VM
 (essentially assigning a card on your bus directly to the VM to be
 completely managed by its kernel) to reduce latency in other ways to
 hardware if you need too.

I'm not disagreeing. It's extra work, it's fragile in configuration,
and that sort of fine tuning is very, very easy to get wrong.


Re: about realtime system

2014-08-24 Thread Nico Kadel-Garcia
On Sun, Aug 24, 2014 at 7:50 PM, jdow j...@earthlink.net wrote:
 The stock exchange could remove most of the problem, meaning high
 frequency trades, by placing a purely random 0 to 1 second latency
 on all incoming data and all outgoing data. The high frequency trading
 reads to me as just another means of skimming now that they're not
 allowed to round down fractional pennies and pocket the change. It's
 time to give mere mortals some practical access to the exchanges. And
 this interest in microsecond clocks would simply vanish from the
 exchanges.

The whole high frequency trading, low latency mess is due to leave the
Linux world, at least for the hosts directly receiving the data, due
to the availability of FPGA's that can live on fiber optic
connections, physically adjacent to the stock market. I can say that
based on interviews I did some years back, without a signed NDA for
the interviews, and based on press articles on the technology.

Generating the rules for the FPGA's, now, *that* is an interesting
potential Linux market, and I can point people to job ads for
precisely this. Tying it back to Scientific Linux, I'd *love* to see
them using Scientific Linux for this due to the support available from
the Scientific Linux world for oddball scientific computing
requirements. And the Scientific Linux built-in integration for 3rd
party repositories like EPEL and ATrpms is invaluable.

 On a different point, the word I can find is that the free version of
 VMWare does not support this high latency sensitivity setting.

 {o.o}   Joanne, Just sayin'

Cool  thanks for looking into it!


Re: about realtime system

2014-08-24 Thread Paul Robert Marino
Seriously lets take the high frequency trading thing off this list and any one else who wants to talk to me as well a out it, I'm perfectly happy to explain it.Further more I'm willing to explain the real problems with the world financial system but not on this list and certainly not on this thread-- Sent from my HP Pre3On Aug 24, 2014 8:55 PM, Nico Kadel-Garcia nka...@gmail.com wrote: On Sun, Aug 24, 2014 at 7:50 PM, jdow j...@earthlink.net wrote:
 The stock exchange could remove most of the problem, meaning high
 frequency trades, by placing a purely random 0 to 1 second latency
 on all incoming data and all outgoing data. The high frequency trading
 reads to me as just another means of skimming now that they're not
 allowed to round down fractional pennies and pocket the change. It's
 time to give mere mortals some practical access to the exchanges. And
 this interest in microsecond clocks would simply vanish from the
 exchanges.

The whole high frequency trading, low latency mess is due to leave the
Linux world, at least for the hosts directly receiving the data, due
to the availability of FPGA's that can live on fiber optic
connections, physically adjacent to the stock market. I can say that
based on interviews I did some years back, without a signed NDA for
the interviews, and based on press articles on the technology.

Generating the rules for the FPGA's, now, *that* is an interesting
potential Linux market, and I can point people to job ads for
precisely this. Tying it back to Scientific Linux, I'd *love* to see
them using Scientific Linux for this due to the support available from
the Scientific Linux world for oddball scientific computing
requirements. And the Scientific Linux built-in integration for 3rd
party repositories like EPEL and ATrpms is invaluable.

 On a different point, the word I can find is that the free version of
 VMWare does not support this "high latency sensitivity" setting.

 {o.o}   Joanne, Just sayin'

Cool  thanks for looking into it!