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In Linux you can run lsof and pipe it though grep for the files you are interested in, for example;
$ lsof | grep db.exe | grep accounts
db.exe    16897      john    6uw     REG      253,0    20012    3413872 /usr/recital100/qa/accounts.dbf
db.exe    16897      john    7u      REG      253,0     4176    3413885 /usr/recital100/qa/accounts.dbx
If you want to check for locks you can use lslk, for example;
$ lslk | grep db.exe | grep accounts
db.exe    16897 253,0 3413872 20012  w 0  0  0 12319   0 /usr/recital100/qa/accounts.dbf
If you don't have lslk installed you can install it with one of the updaters, for example on redhat linux:
$ yum update lslk

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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.

  1. Need to use CAT6 cables
  2. Slow Disk speed
  3. 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!


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After an extended period of intense software development, we are pleased to announce the release of Recital 10 which is a milestone in our development efforts.
 
Recital 10 is comprised of major new versions of all of our products (which are all now Cluster Ready) as well as some new products, and a collection of open source technologies fully supported by ourselves to our customer base. 

The Recital 10 release notes can be found here.
  • Recital

    A powerful scripting language with an embedded database used for developing desktop database applications on Linux and Unix.

  • Recital Server

    A cross-platform SQL database and application server.

  • Recital Web

    A server-side scripting language with an embedded SQL database for creating web 2.0 web applications.

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Usually, you do not need to setup an email server under Linux. Most GUI email clients support Gmail POP3 and IMAP configurations. But, how do you send mail via the standard /usr/bin/mail user agents in a shell script? Programs such as sendmail / postfix / exim can be configured as a gmail smarthost but they are largely overkill for this use. The ssmtp program is a neat utility that does just that for you via gmail.

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Recital provides a wide variety of connectivity solutions to external data sources. This article provides an overview.
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A number of people have complained about data loss after a system crash when using Ext4.  A bug report was logged. According to multiple posts by a developer of Ext4, Theodore Tso, this is due to differences in approach to security and performance issues between the two file systems.

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.
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The ShellEd plugin is a good shell editor for Eclipse
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Occasionally subversion can get itself confused about what is and what is not in a working copy. This usually occurs if you have replaced the contents of a directory such as when you upgrade a component in Joomla!

You receive a message such containing this:

"working copy admin area is missing"

How to resolve this: 

Step 1 -- Rename the directory that is causing the error from a shell prompt and prefix it with __ 

mv com_docman __com_docman

Step 2 -- Using your subversion client refresh your working copy, then "update" the directory that is causing the problem e.g. update com_docman.

Step 3 -- Now you can commit the __com_docman directory.

After you have done this follow these steps, using your subversion client:

Step 4 -- delete the com_docman directory from your working copy
Step 5 -- rename __com_docman back to com_docman

Now "commit all" and both your working copy and repository will be in sync.
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In this article Barry Mavin, CEO and Chief Software Architect for Recital, details Working with Stored Procedures in the Recital Database Server.

Overview

Stored procedures and user-defined functions are collections of SQL statements and optional control-of-flow statements written in the Recital 4GL (compatible with VFP) stored under a name and saved in a Database. Both stored procedures and user-defined functions are just-in-time compiled by the Recital database engine. Using the Database Administrator in Recital Enterprise Studio, you can easily create, view, modify, and test Stored Procedures, Triggers, and user-defined functions

Creating and Editing Stored Procedures

To create a new Stored Procedure,  right-click the Procedures node in the Databases tree of the Project Explorer and choose Create. To modify an existing stored procedure select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it or selecting Modify from the context menu . By convertion we recommend that you name your Stored Procedures beginning with "sp_xxx_", user-defined functions with "f_xxx_", and Triggers with "dt_xxx_", where xxx is the name of the table that they are associated with.

Testing the Procedure

To test run the Stored Procedure, select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it. Once the Database Administrator is displayed, click the Run button to run the procedure.

Getting return values

Example Stored Procedure called "sp_myproc":
parameter arg1, arg2
return arg1 + arg2
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a Stored Procedure that adds to numeric values together
public int CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@arg1, @arg2)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@arg1"].Value = 10;
	cmd.Parameters["@arg2"].Value = 20;
	conn.Open();
	cmd.ExecuteNonQuery();
	int result = (int)(cmd.Parameters["retvalue"].Value);    // get the return value from the sp
	conn.Close();
	return result;
	}

Writing Stored Procedures that return a Resultset

If you want to write a Stored Procedure that returns a ResultSet, you use the SETRESULTSET() function of the 4GL. Using the Universal .NET Data Provider, you can then execute the 4GL Stored Procedure and return the ResultSet to the client application for processing. ResultSets that are returned from Stored Procedures are read-only.

Example Stored Procedure called "sp_myproc":
parameter query
select * from customers &query into cursor "mydata"
return setresultset("mydata")
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// sample code to call a stored procedure that returns a ResultSet
public void CallStoredProcedure()
{
	RecitalConnection conn = new 
		RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
	RecitalCommand cmd = new RecitalCommand();
	cmd.Connection = conn;
	cmd.CommandText = "sp_myproc(@query)";
	cmd.CommandType = CommandType.StoredProcedure;
	cmd.Parameters["@query"].Value = "where not deleted()";
	conn.Open();
	RecitalDataReader dreader = cmd.ExecuteReader();
	int sqlcnt = (int)(cmd.Parameters["sqlcnt"].Value);    // returns number of affected rows
	while (dreader.Read())
	{
		// read and process the data
	}
	dreader.Close();
	conn.Close();
}
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