It would appear that gigabit LAN is not! In fact it often runs at the same speed as 100Mbps LAN. Let's look at why exactly.
After configuring your network you can use the ifconfig command to see what speeds the LAN is connected. Even though 1000Mbps is reported by the card, the reality is that the overall throughtput may well be ~100Mpbs. You can try copying a large file using scp to demonstrate this.
As it turns out, in order to use a gigabit LAN you need to use CAT6 cables. CAT5 and CAT5E are not good enough. End result, the ethernet cards throttle back the speed to reduce dropped packets and errors.
You can find a good article here titled Squeeze Your Gigabit NIC for Top Performance. After tuning up the TCP parameters i found that it made no dfifference. The principal reasons behind low gigabit ethernet performance can be summed up as follows.
- Need to use CAT6 cables
- Slow Disk speed
- Limitations of the PCI bus which the gigabit ethernet cards use
You can get an idea about the disk speed using the hdparm command:
Display the disk partitions and choose the main linux partition which has the / filesystem.
# fdisk -l
Then get disk cache and disk read statistics:
# hdparm -Tt /dev/sda0
On my desktop system the sata disk perfomance is a limiting factor. These were the results:
/dev/sda1:
Timing cached reads: 9984 MB in 2.00 seconds = 4996.41 MB/sec
Timing buffered disk reads: 84 MB in 3.13 seconds = 58.49 MB/sec
Well, that equates to a raw disk read speed of 58.49 * 8 = 467Mbps which is half the speed of a gigabit LAN.
So.. NAS storage with lots of memory looks to be the way to go... If you use the right cables!
We are pleased to announce the release of Recital 10.0.2.
Here is a brief list of features and functionality that you will find in the 10.0.2 release.
- New commands
SAVE/RESTORE DATASESSION [TO variable]
CONNECT "connectString"
DISCONNECT - New functions (OData compatible)
startsWith(haystack as character, needle as character)
endsWith(haystack as character, needle as character)
indexOf(haystack as character, needle as character)
substringOf(haystack as character, needle as character)
concat(expC1, expC2) - New system variables
_LASTINSERTEDSYNCNUM - Enhanced commands
Added CONNSTRING "connectingString" to the USE command to connect to remote servers (Recital, MySQL, PostgreSQL, Oracle, ODBC) - Further SQL query optimizer improvements to boost performance
- Performance improvements in Recital Web
- Forced all temporary files into temp directory (improves performance when local tmpfs is used as temp directory and reduces network i/o)
- Fixed cookie and session variable problems in Recital Web
- Fixed problem with temporary files being left after some server queries involving memos and object data types
- Improved performance of the Windows ODBC driver
- Fixed a security flaw in Recital Web
- Fixed all reported bugs

"Adobe® AIR® is a cross-operating system runtime that lets developers combine HTML, Ajax, Adobe Flash®, and Adobe Flex® technologies to deploy rich Internet applications (RIAs) on the desktop."
The outcome of this combination of technologies is that developers can design and render quite beautiful user interfaces cross platform. For us desktop Linux users it is nice to have

Examples of great Adobe air applications are Adobe.com for My Desktop, TweetDeck and the Times Reader. You can download these applications and many more at the Adobe Marketplace.
The easiest way to install Adobe Air on Fedora 12 is to download the latest build from Adobe, click here.
Once you have downloaded the .bin file do the following at the shell:
su - chmod +x AdobeAIRInstaller.bin ./AdobeAIRInstaller.binOnce you have Air installed, there is a slight tweak you will have to do to get it running on Fedora 12, it is related to the security certificates. This can be remedied in one simple line at the shell prompt as root.
su - for c in /etc/opt/Adobe/certificates/crypt/*.0; do aucm -n $(basename $c) -t true; doneWhat this line is doing is using the aucm which is the Adobe Unix certificate manager to set the certificates installed as trusted.
You will now be able to go to the Adobe Marketplace and download and run Air applications without any issues.
Enjoy!
If you have software packages which you wish to share with others or simply between your own personal machines, a neat and easy solution is to create your own YUM repository and provide your .repo file for download.
YUM is by far the easiest method of installing software on Red hat, Centos and Fedora. Not only does it mean you don't need to trawl the web looking for somewhere to download the packages, YUM does a great job of satisfying any package dependencies. As long as the required packages are available in the enabled repositories on your system, YUM will go out and get everything you need.
To create your own YUM repository, you will need to install the yum-utils and createrepo packages:
yum install yum-utils createrepo
yum-utils contains the tools you will need to manage your soon to be created repository, and createrepo is used to create the xml based rpm metadata you will require for your repository.
Once you have installed these required tools, create a directory in your chosen web server's document root e.g:
mkdir -p /var/www/html/repo/recital/updates
Copy the rpm's you wish to host into this newly created directory.
The next step is to create the xml based rpm metadata. To create this use the createrepo program we installed earlier.
At the shell type the following command:
createrepo -v -s md5 /var/www/html/repo/recital/updates
This will create the required metadata in the repodata directory of your /var/www/html/repo/recital/updates directory.
root@test repodata]# ls -l rwotal 44 -rw-r--r-- 1 root root 28996 Jan 13 21:42 filelists.xml.gz -rw-r--r-- 1 root root 284 Jan 13 21:42 other.xml.gz -rw-r--r-- 1 root root 1082 Jan 13 21:42 primary.xml.gz -rw-r--r-- 1 root root 951 Jan 13 21:42 repomd.xml
To do a final consistency check on your repository run the following command:
verifytree /var/www/html/repo/recital/updates
We now have a fully functioning YUM repository for our hosted rpm packages.
The next process is to create a .repo file in the client systems /etc/yum.repos.d directory.
Navigate to the /etc/yum.repos.d directory on your system as root.
Using your preferred text editor to create the .repo file. In this example I will call it recital.repo.
Now paste in the following lines:
[Recital] name=Recital Update Server baseurl=http://ftp.recitalsoftware.com/repo/recital/updates enabled=1 gpgcheck=1
Once that is saved, at the shell prompt on the same machine (YUM client system).
$ yum repolist Loaded plugins: presto, refresh-packagekit repo id repo name status Recital Recital Update Server enabled: 1 adobe-linux-i386 Adobe Systems Incorporated enabled: 17 fedora Fedora 12 - i386 enabled: 15,366
As you can see the Recital repo is now being picked up and we have access to all the packages it is hosting.
See how easy that was!
Unfortunately java does not support __FILE__ and __LINE__ but you can get the same functionality with this code which can be placed in one of your libraries.
public static void showTrace(String msg) { if (msg.length() > 0) System.out.println(msg); System.out.println("Trace: " + "file " + new Throwable().getStackTrace()[1].getFileName() + " class " + new Throwable().getStackTrace()[1].getClassName() + " method " + new Throwable().getStackTrace()[1].getMethodName() + " line " + new Throwable().getStackTrace()[1].getLineNumber()); }
// declare some simple procedures proc display(cArg) echo "display=" + cArg endproc proc show(cArg) echo "show=" + cArg endproc // create an object based on an anonymous class myobj = new object() // add some properties myobj["name"] = "barry" myobj["company"] = "recital" // now declare an anonymous method myobj["mymethod"] = display // call the method myobj.mymethod("hello world") // displays "display=hello world" // redeclare the method myobj["mymethod"] = show // call the method myobj.mymethod("hello world") // displays "show=hello world"Where this becomes particularly useful is when you have a procedure that calls anonymous methods in order to process data. This technique can be used to call anonymous procedures in your code.
proc processdata(oArg) oArg.mymethod(oArg.name) endproc proc show(cArg) echo "show=" + cArg endproc myobj = new object() myobj["name"] = "barry" myobj["mymethod"] = show processdata(myobj) // displays "show=barry"
Ext3 commits writes to disk within approximately 5 seconds - Ext4 can take from 40-150 seconds. In addition, if a system is using Ext3 and crashes before the commit takes place you will still have the previous contents of a file where under Ext4 the file will be empty. Theodore Tso feels that this is a failure at the application level and that the file system is behaving as designed and as specified by the POSIX spec (which apparently does not specify what is supposed to happen when a system is not shut down cleanly). His solution to the issue is to suggest proper use of fsync() and lists various scenarios/examples in post 54 of the bug report (linked above). In addition he wrote a patch that recognize the rename() situation mentioned in his post 54 yet retains the normal Ext4 behaviors and performance in the majority of cases. Also a more "proper" solution has been provided which allows the behavior of Ext3 to be retained under Ext4 by mounting it with alloc_on_commit.
A somewhat related topic is the use of on-board caching by hard drives. This behavior can be modified on most drives by using hdparm.
RTOS()
Syntax
RTOS( [ <workarea> ] )Description
The RTOS() function returns all the fields in the current row as a string. The string will begin with the unique row identifier and then the deleted flag, followed by the data in the record. An optional workarea can be specified, otherwise the current workarea will be usedExample
use backup in 0 use accounts in 0 nrecs=reccount() for i = 1 to nrecs if rtos(accounts) != rtos(backup) debug("record "+recno()+" don't match") endif next
// determine how many Recital users are on the system nusers = pipetostr("ps -ef | grep db.exe | wc -l")