Linux-Development-Sys Digest #770, Volume #6 Thu, 3 Jun 99 05:14:46 EDT
Contents:
Re: What are the differences between mySQL and mSQL? (Paul D. Smith)
Re: What are the differences between mySQL and mSQL? ("Jon Smirl")
Re: SMP needlessly migrating processes between processors? (bill davidsen)
Re: Linux development tools... ("Dirk-Jan C. Binnema")
Re: Terabite Plus Filesystems (bill davidsen)
Re: RAID-1 and 5 broken in 2.2.9? (bill davidsen)
Re: kernel vs egcs vs PentiumPro/II (Matt Bartley)
Re: Terabite Plus Filesystems ("Stefan Monnier "
<[EMAIL PROTECTED]>)
Re: What are the differences between mySQL and mSQL? (Paul D. Smith)
Re: Strange partial write on sockets problem (Tony Scholes)
Re: Strange partial write on sockets problem ("Duncan Stodart")
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (Paul D. Smith)
Crossposted-To:
comp.os.linux.development.apps,comp.os.linux.misc,comp.os.linux.setup,comp.lang.java.databases
Subject: Re: What are the differences between mySQL and mSQL?
Date: 03 Jun 1999 00:49:25 -0400
Reply-To: [EMAIL PROTECTED]
%% [EMAIL PROTECTED] writes:
p> According to Ruiming Chen <[EMAIL PROTECTED]>:
>> The Subject askes its all. Are they the same free database software
>> with two names? Or they are two different free database software?
>> Are they both run on Linux?
p> MySQL started out as a set of matches to mSQL by a team of application
p> programmers who wrote a package arround mSQL. When they realized the
p> limitations of mSQL, and that no amount of patches would get arround
p> them, they re-wrote their own database engine internally from the
p> ground up, but maintained (more or less) the same external (mSQL)
p> interface.
This is a common misconception, but it is not true. The database engine
of MySQL is significantly older and more mature than the entire mSQL
package; originally, though, it wasn't used with an SQL database. Heck,
mSQL has only had even acceptable indexing since mSQL 2.0 was released
what, a year ago?
When TcX decided to modify the database engine to be an SQL database,
they did use mSQL as the model for the API, etc. They wanted the MySQL
interface to be a drop-in replacement for those using mSQL.
Since then, it has diverged significantly.
--
===============================================================================
Paul D. Smith <[EMAIL PROTECTED]> Network Management Development
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist
===============================================================================
These are my opinions---Nortel Networks takes no responsibility for them.
------------------------------
From: "Jon Smirl" <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux.development.apps,comp.os.linux.misc,comp.os.linux.setup,comp.lang.java.databases
Subject: Re: What are the differences between mySQL and mSQL?
Date: Thu, 3 Jun 1999 01:12:05 -0400
It's not clear to me that I want the ability to modify my database engine.
Commercial versions of these engines go through extreme reliability testing
before being released.
Sybase on Linux is completely free in binary form - check out
http://linux.sybase.com. If you want to use Perl you don't have to buy
anything.
The Sybase Java driver for Linux is not free, but you only need the
workplace version to cover Linux.
http://www.sybase.com/products/internet/jconnect/ It costs $495. This gives
you an unlimited user, commerical deployment license. $495 is less than
msql/mysql would cost for commercial use. There is a free eval of JConnect
available too.
If you want to use the Sybase Linux server from Windows, just configure the
Microsoft SQL Server ODBC driver to point to the Linux server. MS SQL and
Sybase SQL were the same product at one time and they are very compatible
with each other. You can get ADO support with the ADO:ODBC bridge.
Sybase is a full feature database engine that is the flagship product of a
billion dollar software company. It is extremely reliable and well tested.
The Sybase engine supports thing like hot backup, mirrored servers, two
phase commit, multiple language sorting, SMP, etc. that are not availabe in
the mSQL/mySQL packages.
Oracle and Informix and also offering free versions of their engines for
development purposes only. Expect a big bill ($10-50K) from them when your
app goes live.
Jon Smirl
[EMAIL PROTECTED]
------------------------------
From: [EMAIL PROTECTED] (bill davidsen)
Subject: Re: SMP needlessly migrating processes between processors?
Date: 2 Jun 1999 21:46:22 GMT
In article <[EMAIL PROTECTED]>,
Skip Montanaro <[EMAIL PROTECTED]> wrote:
| I recently started running RH 5.2 on a dual P-II box (Tyan Thunderbolt
| motherboard). I'm running kernel 2.2.9. When I run a single
| CPU-intensive process and launch xosview to watch things, I see a
| pattern of CPU load that suggests to me that the single busy process is
| migrating back and forth between the processors roughly every half
| second or so. I see a little square wave pattern for the user time
| portion of the two CPU's graphs. The patterns for the two processors
| are roughly 180 degrees out of phase with one another. It seems to me
| that the scheduler isn't weighting things heavily enough to keep
| processes from migrating too much. Is this normal? Isn't there a cache
| flush overhead when migrating processes between processors?
Skip,
There is some overhead, but one flush every 500ms is not going to hurt
anything. The weighting method tends to make a process stay with a
processor by running something else a little if the desired processor
isn't available. If you up this value you get better binding but the
performance will be worse because the process will wait more for the
desired CPU.
Worse than that, the longer it waits the less chance of anything
useful being in the cache, and you get both the wait and the cache
flush penalties. In terms of real time it's best to have the time a
process waits for a given CPU similar to the flush penalty. Therefore,
play with the value, satisfy yourself that it is a very well chosen
value in most cases, and be happy.
Your xosview is probably the cause of some of this, it is known to
make the problem worse. It shows because your system is lightly loaded,
I bet. Under heavier load you won't see it.
--
bill davidsen <[EMAIL PROTECTED]> CTO, TMR Associates, Inc
The Internet is not the fountain of youth, but some days it feels like
the fountain of immaturity.
------------------------------
From: "Dirk-Jan C. Binnema" <[EMAIL PROTECTED]>
Subject: Re: Linux development tools...
Date: Thu, 3 Jun 1999 00:37:13 +0200
Hi there,
Chris White wrote in message <7ivfgf$90a$[EMAIL PROTECTED]>...
>Can anyone suggest some good tools for developing applications for X
>Windows? I come from the Microsoft Windows world and I think Visual C++
has
>me spoiled. :) Please help so I can break away from the Microsoft grasp.
>
>Chris
Check VDK, a widgetlib (based on GTK+) and a GUI, which is inspired by
Inprise C++ builder, and looks a bit like MFC (message maps etc.).
You'll be impressed!
http://www.guest.net/homepages/mmotta/VDKHome/index.htm
Cheers,
Dirk-Jan
------------------------------
From: [EMAIL PROTECTED] (bill davidsen)
Crossposted-To:
comp.os.ms-windows.nt.admin.misc,comp.sys.sun.admin,comp.sys.hp.misc,comp.os.linux.hardware
Subject: Re: Terabite Plus Filesystems
Date: 2 Jun 1999 22:01:18 GMT
In article <[EMAIL PROTECTED]>,
Jake Maizel <[EMAIL PROTECTED]> wrote:
| We are building a system that needs to handle a huge number of files
| that are 500KB-1MB in size (1-2TB total). Our only constraint right now
| is the desire to use intel-based hardware for the host computers for
| cost purposes.
At the risk of getting blasted here, have you looked at SCO? Their
UNIXware stuff has a large number of filesystem types, and I think you
would find them at least worthy of evaluation.
| My question really is regarding which OS would best
| handle a filesystem of this size. We are using lots of unix and NT so
| we don't have a bias one way but we don't have experience with any OS
| using a filesystem this big. What we are considering for hardware are
| HP LPr hosts connected to a AL-FC RAID system (probably HP). We would
| want to pick either HPUX, linux, NT or Solaris x86. Any experience
| that could be passed would be great.
I would avoid using AIX (I know you didn't mention it) for any
application which has a large number of files in a single directory. I
know Linux will handle this, but I have no idea how well.
Having used EMC2 and Hitachi RAID boxes I would favor Hitachi by a bit,
although either can and will fail if you use it long enough.
Final thought, backup. RAID isn't perfect, and even the best servers can
fail in a way which corrupts data.
--
bill davidsen <[EMAIL PROTECTED]> CTO, TMR Associates, Inc
The Internet is not the fountain of youth, but some days it feels like
the fountain of immaturity.
------------------------------
From: [EMAIL PROTECTED] (bill davidsen)
Subject: Re: RAID-1 and 5 broken in 2.2.9?
Date: 2 Jun 1999 21:16:49 GMT
In article <7invp0$51c$[EMAIL PROTECTED]>, bill davidsen <[EMAIL PROTECTED]> wrote:
| I think there is a problem in md support for raid-1 and 5 in 2.2.9. I
| have no problem with raid-0, but neither of the reliable personalities
| works. I get phantom superblock errors in both cases.
|
| I can't seem to find a site with a newer md utils, the Documentation
| says only linear and raid-0 are supported then on the next line talks
| about using raid-1. The kernel has raid-1 and raid-5 modules, and the
| raid-1 used to work.
I guess the answer is that the RAID-[145] stuff in the 2.2.9 kernel
doesn't work at all with anything any more (why is it there?). The md
stuff got broken somewhere along the line, and the raidtools stuff only
works after adding about 200k worth of patches (not a typo), and those
are alpha and only available for a few kernels, 2.0.36 and 2.2.6.
Shame to see stuff which worked broken.
--
bill davidsen <[EMAIL PROTECTED]> CTO, TMR Associates, Inc
The Internet is not the fountain of youth, but some days it feels like
the fountain of immaturity.
------------------------------
From: [EMAIL PROTECTED] (Matt Bartley)
Crossposted-To: comp.os.linux.development.apps
Subject: Re: kernel vs egcs vs PentiumPro/II
Date: 2 Jun 1999 23:00:02 -0700
In article <[EMAIL PROTECTED]>,
Paul Kimoto <[EMAIL PROTECTED]> wrote:
>In article <[EMAIL PROTECTED]>, Conrad Sanderson wrote:
>> what is -Os ?
>See the gcc info pages, of course! But in case you don't have an egcs
>installation at hand (as this is a new option):
>
>> `-Os'
>> Optimize for size. `-Os' enables all `-O2' optimizations that do
>> not typically increase code size. It also performs further
>> optimizations designed to reduce code size.
Some time ago I read about a command line option to gcc and/or egcs,
similar to "-v" but more verbose, which among other things shows all
the the "-f<optimisation>" flags which are in effect at the current
"-O" level.
I've looked through the docs time and time again, trying to find that
again, and haven't been able to. What is that option?
--
"When PCs run new applications successfully, most people feel relief
and almost pathetic gratitude - a standard of reliability tolerated in
no other consumer product."
_Economist_, Sept. 12 1998
------------------------------
From: "Stefan Monnier <[EMAIL PROTECTED]>"
<[EMAIL PROTECTED]>
Crossposted-To:
comp.os.ms-windows.nt.admin.misc,comp.sys.sun.admin,comp.sys.hp.misc,comp.os.linux.hardware
Subject: Re: Terabite Plus Filesystems
Date: 03 Jun 1999 02:11:33 -0400
>>>>> "Al" == Al in Seattle <[EMAIL PROTECTED]> sent this flame-bait:
> Well after all the sh** that I have taken because I dared to stand up and
> just *question* using NT versus Unix on this thread, I open up June 1999
> WinNT mag and on page 78, is a story about NCSA using a 192 processor
> cluster of off the shelf NT dual processor boxes, using off the shelf NT
> SP3.
> While I understand that this is not a terabite file system being used in it,
> you Unix Bigots that have said that NT doesn't scale ought to at least read
> the article. The person managing the system apparently has been very happy
> with it. Considers it an unqualified success.
WinNT mag is at least as biased towards NT as comp.os.linux.* is towards Linux.
Being mostly financed by Microsoft, they are unlikely to feature an article
about how NT is unusable.
Now, for the actual content, you'll note that indeed, a cluster of 96
bi-processors has very little to do with what was being discussed.
You don't mention what the cluster was used for, but you'll note that
I expect most OS designers to look at such clusters as the evidence that
the OS itself doesn't scale (the 192 processors were not a single-system
image). NT machines are also very often clustered for reliability reasons
(failover and friends) which is sometimes considered a tribute to NT's
instability, I don't know if that was the case for that NCSA example.
All unix vendors like Sun, HP, ... sell machines with terabyte filesystems
on a regular basis, which is something that cannot be said of NT (or Linux for
that matter).
So, yes, maybe NT can deal with such amounts of disk, maybe Linux can deal
with it also, but I haven't seen any evidence for such competence, whereas
there is ample evidence for the other Unix guys, hence the recommendation to go
with such a machine.
Stefan
------------------------------
From: [EMAIL PROTECTED] (Paul D. Smith)
Crossposted-To:
comp.os.linux.development.apps,comp.os.linux.misc,comp.os.linux.setup,comp.lang.java.databases
Subject: Re: What are the differences between mySQL and mSQL?
Date: 03 Jun 1999 01:53:51 -0400
Reply-To: [EMAIL PROTECTED]
%% "Jon Smirl" <[EMAIL PROTECTED]> writes:
js> It's not clear to me that I want the ability to modify my database
js> engine. Commercial versions of these engines go through extreme
js> reliability testing before being released.
MySQL can be modified to do such things as add new types, functions,
etc. Sometimes people need this flexibility in order to make their
database accesses sufficiently fast or useful.
However, I'm not denying that Sybase is a much more powerful engine than
MySQL and supports many features it doesn't. Obviously if you require
transactions, etc. then MySQL is definitely not for you.
I'm merely pointing out that, as behooves us on a Linux newsgroup, when
I say "this app is free" I mean much, much more than just "it doesn't
cost anything".
js> The Sybase engine supports thing like hot backup, mirrored
js> servers, two phase commit, multiple language sorting, SMP,
js> etc. that are not availabe in the mSQL/mySQL packages.
Agree for all this... except SMP? MySQL is a threaded solution so it
should be able to take full advantage of SMP. Certainly mSQL, which is
single process/single thread, cannot make much use of SMP.
On the other hand, all these features come with a cost, in speed,
complexity of management, minimum hardware requirements, etc.: for many
purposes a very fast, reliable, lightweight solution like MySQL is more
appropriate.
--
===============================================================================
Paul D. Smith <[EMAIL PROTECTED]> Network Management Development
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist
===============================================================================
These are my opinions---Nortel Networks takes no responsibility for them.
------------------------------
Date: Thu, 03 Jun 1999 09:51:03 +0200
From: Tony Scholes <[EMAIL PROTECTED]>
Subject: Re: Strange partial write on sockets problem
Scott Lanning wrote:
>
> Tony Scholes ([EMAIL PROTECTED]) wrote:
> : Works fine everywhere (and I mean everywhere, name a UNIX system
> : over the last 12 years and it's worked there) apart from on Red
> : Hat Linux that is.....
>
> Presumably you mean any Linux, as it seems any distribution with
> the same kernel and glibc would have same behavior.
>
Guess so, but I've only got RH to play with at the mo....
> : Example, write writes 1338 bytes, remote socket receives only 684,
> : and this is consistent... We can trace on the terminal server how
> : many bytes it sends down the serial wire (and thus how many it has
> : received on the socket)
>
> But perhaps there is a serial driver between sockets, so bytes sent
> doesn't equal bytes received at socket.
>
No, serial driver is after the socket on the terminal server... RH ->
Terminal Server is same segment, same subnet Ethernet...
> : Scary thing is, if I use gdb to trace the code, it works, though
>
> Don't let the penguin smell the fear.. :) I think gdb probably has
> some extra control over buffering.
>
> : Any ideas whatsoever, as to what might cause this? Some kind of
> : timing issue?
>
> Or maybe a buffering issue. Quick brainstorm:
>
> 1) serial port received all 1338 bytes, but socket only received
> 684 of them before closing (for some reason?)
>
> 2) buffer overflowed, extra characters lost. In particular, there
> may be some kind of MAX_BUF_LIMIT which is different in Linux than
> in other Unixes (seems more likely, no?)
>
I've played a bit more, and it looks as though it is some issue with the
TCP/IP on the Terminal Server....
Using tcpdump, I see that all 1338 bytes are sent (as 3 packets of 580,
580, 178) and the data in each packet is correct, all seems fine here..
in other words I,m pretty sure that the Linux server sends all the data
corectly, and it would seem to be received at the socket on the terminal
server, but still, only 684 get sent out of the serial port....
Also, wrote a small server program that just dumps bytes received on
it's listening socket to a file, and pointed the program on Linux at it,
all data received AOK, ran the server on several differenct UNICES, nop
problems....
It's looking like it's the terminal server which is unhappy about
something in the packets it receives from Linux, God knows what
though...
> --
> Scott Lanning: [EMAIL PROTECTED], http://physics.bu.edu/~slanning
> "If lightning is the anger of the gods, the gods are concerned mostly
> with trees." --Lao Tse
--
Tony Scholes
Technical Manager
===============================================================================
Beacon Computer Services Tel: +44 (0)1582 478888
The Friars, 82 High Street South Fax: +44 (0)1582 478810
Dunstable, Beds. UK Email: [EMAIL PROTECTED]
LU6 3HD Compuserve: 72660,207
===============================================================================
------------------------------
From: "Duncan Stodart" <[EMAIL PROTECTED]>
Subject: Re: Strange partial write on sockets problem
Date: Thu, 3 Jun 1999 18:23:02 +1000
Tony Scholes wrote in message <[EMAIL PROTECTED]>...
>Hi
>
>Environment: Redhat 5.1/5.2, gcc 2.7.2.3, glic 2.0.7
>
>We have a simple program that opens a socket connection, reads the
>contents of a file and then writes it to the socket, it's role in life
>is to enable us to glue printers on serial terminal servers (such as
>ShivaPort ATOMS) to the printing system on a UNIX/Linux server... We
>make the print system output to a named pipe then have this program sit
>there forever reading from the named pipe and writing to the socket on
>the terminal server...The socket on the terminal server is associated
>with one of it's serial ports, and anything it receives on the socket,
>it sends to the serial port...
>
>Works fine everywhere (and I mean everywhere, name a UNIX system over
>the last 12 years and it's worked there) apart from on Red Hat Linux
>that is.....
>
>The system we get is that the tail of the print job is sometimes lost
>(not for every job, but if a particular job fails, it always fails)..
>tracing the code, it appears that the write of the data to the socket
>returns the correct number of bytes written, but only the 1st so many
>bytes appear to arrive at the remote socket...!?
>
>Example, write writes 1338 bytes, remote socket receives only 684, and
>this is consistent... We can trace on the terminal server how many bytes
>it sends down the serial wire (and thus how many it has received on the
>socket)
>
>Scary thing is, if I use gdb to trace the code, it works, though not if
>I run the binary generated with -g outside of of gdb.....1
>
I've had similar problems with terminal servers. Is the terminal server
returning
anything when you get the buffer overflow? What I found in my case is
if I sent characters to the terminal server too quickly it through away
(buffer
overflow) characters. What gave it away was that the terminal server
returned
a bell character (as if I was typeing too fast). Fix was to slow down the
'entry'
of characters on the terminal server via the socket session. Ugly but it
worked.
------------------------------
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