Recital's version of Samba allows application data to be shared and locked correctly across these systems, allowing a truly integrated heterogeneous data environment. For example Recital applications running on a UNIX/Linux server can read and update FoxPro databases residing on a Microsoft Windows NT server through the use of Samba.

DB_SAMBA=YES ;export DB_SAMBA 

preserve case = no 
default case = lower 
mangle case = yes 

oplocks = False 
share modes = no

This article talks about the log files available in Recital products and how to enable logging when required.

Overview

When discussing a problem with the Recital Support Team, one of the most common requests is that you enable logging and send them the log files produced. Log files along with error files are designed to provide detailed information about Recital processes and the prevailing environment and can be a fast-track to resolving a problem.

Log Files

There are three main types of log file:

1. System Log
2. Client/Server Communication Logs
3. Custom Logs

System Log

The System log is a system-wide  all product log.  It tracks all login and logout operations from either Recital or the Recital Server. Logout details include the exit code: 0 for an error-free, 'normal' exit and the error number and message when an error has occurred. It also shows the licenses that have been loaded and any license error codes and messages. The system log filename is recital.log.
 

Client/Server Communication Logs

The Client/Server communication logs track the requests and responses between the Recital Server and its clients. The log files are as follows:

Filename	Type	Description
dbserver.log	System-wide	The Recital Server startup log. This logs any problems with the Recital Server startup.
port.log	System-wide	The port listener log. The port listener (or portserver) listens on port 8001 for client connection requests and spawns the appropriate server process.
net.log	Connection	The netserver log. The netserver is the Recital Server database and 4GL engine.
rsi.log	Connection	The Recital Server Interface (RSI) Gateway log. This logs communication with the Database Gateways to SQL databases.
rec.log	Connection	The Recital Database Gateway log. The Recital Database Gateway (or recserver) is the SQL database engine for Recital Gateway data access.
mys.log	Connection	The MySQL Database Gateway log.
ora.log	Connection	The Oracle Database Gateway log.
inf.log	Connection	The Informix Database Gateway log.
ing.log	Connection	The Ingres Database Gateway log.
pos.log	Connection	The PostgreSQL Database Gateway log.
jdb.log	Connection	The JDBC Driver Database Gateway log.

Custom Logs

The Recital/4GL USERLOG() function can be used to log information to a user-specific log file for debugging or audit trail purposes. For full information on this function, please see the USERLOG() documentation.

Enabling Log Files

For instructions on enabling log files for individual products, please follow these links:

• Recital Server for Windows
• Recital Server for Linux
• Recital Server for UNIX
• Recital Server for OpenVMS
• Recital for Linux
• Recital for UNIX
• Recital for OpenVMS

Enabling Log Files: Recital Server for Windows

To enable the system log file for the Recital Universal Application Server for Windows, include the following command in the UAS\config.db file:

set syslogging on

The Recital Server Manager System Logging tab allows for the viewing and resetting of the System log.

Section

Item

Description

System Logging

DateTime

Date and time stamp of the action.

Name

Login name used by connection

Action

Action logged: Login, Logoff, Errot

Details

Details of action

Buttons

Purge

Allows the log file to be reset

Refresh

Refreshes the display

To set up Client/Server logging, use the Recital Server Manager Settings tab to update the server's Registry entries:

The following Log file settings can be configured:

Item	Description
Log files Directory Path	Enter the directory in which log files will be created. The default is the UAS\log directory.
Enabled	Check to enable log file creation.
Versions	Check to enable log file versioning.
Listener	Click to view the current port listener log file
Server	Click to view the current netserver log file
Purge	Click to purge all log files

Enabling Log Files: Recital Server for Linux

To enable the system log file for the Recital Server for Linux, include the following command in the conf/config.db file:

set syslogging on

To set up Client/Server logging, the Recital Server can be started with the 'logging' parameter, in which case, all relevant logging will take place.

# service startup logging<

Alternatively, one or more of the following environment variables can be added to the dbserver.conf file or set at the Operating System prompt.  The Recital Server must be restarted before environment variable changes will be recognized.  Each environment variable should be set to the name of a log file.

Environment Variable

Logs Activity of...

UASLOG_PORT

Port Server (db_rsiserver)

UASLOG_NET

(Net) Server (db_netserver)

UASLOG_ORA

Oracle Server (db_oraserver)

UASLOG_INF

Informix Server (db_infserver)

UASLOG_ING

Ingres Server (db_ingserver)

UASLOG_JDB

JDBC Server (db_jdbserver)

UASLOG_REC

Recital Server (db_recserver)

Extract from recital.conf:

UASLOG_PORT="port.log" ; export UASLOG_PORT
UASLOG_NET="net.log"   ; export UASLOG_NET
UASLOG_ORA="ora.log"  ; export UASLOG_ORA
UASLOG_INF="inf.log"     ; export UASLOG_INF
UASLOG_ING="ing.log"   ; export UASLOG_ING
UASLOG_JDB="jdb.log"   ; export UASLOG_JDB
UASLOG_REC="rec.log"   ; export UASLOG_REC

DB_LOGDIR

If the environment variable DB_LOGDIR is set to an existing directory, all log files will be written to this directory.  If not, the log files will be created in the bin directory.

DB_LOGDIR is set in the conf/recital.conf file. By default it is set to the log directory:

DB_LOGDIR=${ROI_ROOT}log/           ; export DB_LOGDIR

DB_LOGVER

If the environment variable DB_LOGVER is greater than 0, version numbers are added to the file names.  For example, the activity of the first Net Server process will be logged to net.log, the second to net001.log, the third to net002.log etc. up to the maximum value of DB_LOGVER.

DB_LOGVER is set in the conf/recital.conf file:

DB_LOGVER=10; export DB_LOGVER

Enabling Log Files: Recital Server for UNIX

To enable the system log file for the Recital Server for UNIX, include the following command in the conf/config.db file:

set syslogging on

To set up Client/Server logging, the Recital Server can be started with the 'logging' parameter, in which case, all relevant logging will take place.

# service startup logging

Alternatively, one or more of the following environment variables can be added to the <em>dbserver.conf</em> file or set at the Operating System prompt.  The Recital Server must be restarted before environment variable changes will be recognized.  Each environment variable should be set to the name of a log file.

Environment Variable

Logs Activity of...

UASLOG_PORT

Port Server (db_rsiserver)

UASLOG_NET

(Net) Server (db_netserver)

UASLOG_ORA

Oracle Server (db_oraserver)

UASLOG_INF

Informix Server (db_infserver)

UASLOG_ING

Ingres Server (db_ingserver)

UASLOG_JDB

JDBC Server (db_jdbserver)

UASLOG_REC

Recital Server (db_recserver)

Extract from recital.conf:

UASLOG_PORT="port.log" ; export UASLOG_PORT
UASLOG_NET="net.log"   ; export UASLOG_NET
UASLOG_ORA="ora.log"  ; export UASLOG_ORA
UASLOG_INF="inf.log"     ; export UASLOG_INF
UASLOG_ING="ing.log"   ; export UASLOG_ING
UASLOG_JDB="jdb.log"   ; export UASLOG_JDB
UASLOG_REC="rec.log"   ; export UASLOG_REC

DB_LOGDIR

If the environment variable DB_LOGDIR is set to an existing directory, all log files will be written to this directory.  If not, the log files will be created in the bin directory.

DB_LOGDIR is set in the conf/recital.conf file. By default it is set to the log directory:

DB_LOGDIR=${DB_ROOT}log/           ; export DB_LOGDIR

DB_LOGVER

If the environment variable DB_LOGVER is greater than 0, version numbers are added to the file names.  For example, the activity of the first Net Server process will be logged to net.log, the second to net001.log, the third to net002.log etc. up to the maximum value of DB_LOGVER.

DB_LOGVER is set in the conf/recital.conf file:

DB_LOGVER=10; export DB_LOGVER

Enabling Log Files: Recital Universal Application Server for OpenVMS

To enable the system log file for the Recital Universal Application Server for OpenVMS, include the following command in the db_uas:config.db file:

set syslogging on

To set up Client/Server logging, one or more of the following symbols can be added to the <em>db_uas:login.com</em> file.  The Recital Server must be restarted before symbol changes will be recognized.  Each symbol should be set to the name of a log file.

Symbol

Logs Activity of…

UASLOG_PORT

Port Server (db_rsiserver)

UASLOG_NET

(Net) Server (db_netserver)

UASLOG_ORA

Oracle Server (db_oraserver)

UASLOG_INF

Informix Server (db_infserver)

UASLOG_ING

Ingres Server (db_ingserver)

UASLOG_JDB

JDBC Server (db_jdbserver)

UASLOG_REC

Recital Server (db_recserver)

Extract from db_uas:login.com

$ uaslog_port :==  port.log
$ uaslog_net  :==  net.log
$ uaslog_ora  :==  ora.log
$ uaslog_inf  :==  inf.log
$ uaslog_ing  :==  ing.log
$ uaslog_jdb  :==  jdb.log
$ uaslog_rec  :==  rec.log

DB_LOGDIR

If the symbol DB_LOGDIR is set to an existing directory, all log files will be written to this directory.  If not, the log files will be created in the UAS directory.

DB_LOGDIR is set in the db_uas:login.com file. By default it is set to the UAS.log] directory:

$db_logdir    :== 'db_root'.log]               ! system logging directory

DB_LOGVER

If the symbol DB_LOGVER is enabled, version numbers are added to the file names. For example, the activity of the first Net Server process will be logged to net.log, the second to net001.log, the third to net002.log etc.

DB_LOGVER is set in the db_uas:login.com file:

$db_logver  :== true                           ! enable multiple log files

Enabling Log Files: Recital for Linux

To enable the system log file for Recital for Linux, include the following command in the conf/config.db file:

set syslogging on

Enabling Log Files: Recital for UNIX

To enable the system log file for Recital for UNIX, include the following command in the conf/config.db file:

set syslogging on

Enabling Log Files: Recital for OpenVMS

To enable the system log file for Recital for OpenVMS, include the following command in the db_ovd:config.db file:

set syslogging on

In Brief

• Log files provide important information to aid problem resolution, but they are also an overhead, so logging should only be enabled when required, not in normal production operation.
• The System log provides a system-wide view of logins, exits and error codes.
• The System log can be viewed in table format via the SYSLOGGING System Table.
• The System log is enabled using the SET SYSLOGGING ON Recital/4GL command in the conf/config.db file.
• Client/Server logs provide detailed information on client/server requests and responses.
• Client/Server logs are enabled using environment variables, symbols or Registry entries or by specifying the 'logging' parameter when starting the Recital Server.
• The location of log files is determined by the DB_LOGDIR setting.
• Versioning of log files is determined by the DB_LOGVER setting.

This article examines the advantages of using databases and looks at how to create databases for new and existing applications.

Overview

file which contains information, including full path details, about all the files that belong to that particular database. Opening a database gives an application access to all that database's files - operating system and data dictionary protection and security permitting - in whichever directory on the system they reside and database commands can target the files as a single unit.

NOTE: The word 'database' has often been used in Xbase products to refer to an individual '.dbf' file. In this article these are referred to as 'tables' and a database may contain many tables.

Advantages

Recital has always offered developers the maximum in flexibility in the design and deployment of their applications. The SET DEFAULT and SET PATH commands along with the ability to access files via their full Operating System path name has allowed data and code to be created and stored in any required location. Such flexibility does however put the onus on the developer to manage all elements of the application and ensure that maintenance tasks cover all files. The introduction of the database commands retains the established developer-driven design, but provides functionality to facilitate the access and maintenance of the components of that design. The functionality offered is in three main areas:

• Facilitate data access
• Facilitate the storage and extraction of information about the files in an application
• Facilitate the maintenance of the files in an application

These three areas are looked at in more detail in the sections below.

Data Access

The immediate effect of using a database is that all the database's tables and associated files (indexes, dictionaries, memo files) are accessible with the issue of a single command, the OPEN DATABASE command.

// Open the database
> open database southwind
// List the database tables
> list tables

Tables in Database southwind:
 Name                Source
 categories		/usr/recital/data/southwind/categories.dbf
 customers		/usr/recital/data/southwind/customers.dbf
 employees		/usr/recital/data/southwind/employees.dbf
 example		/usr/recital/data/southwind/example.dbf
 order_details	/usr/recital/data/southwind/order_details.dbf
 orders			/usr/recital/data/southwind/orders.dbf
 productsbyname	/usr/recital/data/southwind/productsbyname.dbf
 products		/usr/recital/data/southwind/products.dbf
 shippers		/usr/recital/data/southwind/shippers.dbf
 suppliers		/usr/recital/data/southwind/suppliers.dbf
 cisamdemo		/usr/recital/data/southwind/cisamdemo.dbf

> use example

In the case of the sample southwind database that ships with Recital products on all platforms and is shown above, this effect can be achieved in other ways (SET PATH or SET DEFAULT), since its files all reside in the southwind directory. The database advantage comes when the database catalog contains files from multiple directories, e.g.

// Open the database
> open database myapp
// List the database tables
> list tables

Tables in Database myapp:
  Name                Source
  zipcodes		/usr/myapp/data/lookups/zipcodes.dbf
  customers		/usr/myapp/data/current/customers.dbf
  archive03		/usr/myapp/data/archive/archive03.dbf
  archive04		/usr/myapp/data/archive/archive04.dbf
  users			/usr/allapps/data/users.dbf
  menus		/usr/myapp/data/system/menus.dbf

// Open a table
> use users

The OPEN DATABASE command requires only the database name to be specified, not the complete path of a directory as with SET PATH or SET DEFAULT. Databases are searched for in the sub-directories of the directory defined in the DB_DATADIR environment variable or symbol. DB_DATADIR is set in the system wide configuration file.

#---------------------------------------------------
# location of directories and important files
#---------------------------------------------------
DB_DATADIR="${ROI_ROOT}data/"     ;export DB_DATADIR

NOTE: DB_DATADIR is read from these files at startup to determine the home directory for databases. Updates to DB_DATADIR once a Recital process is running do not change this setting. The OPEN DATABASE command and certain other database commands allow a '?' to be specified in place of a database name. In this case the 'Select a file' dialog is displayed, listing the available files in the DB_DATADIR directory.

Click image to display full size

Fig 1: Recital Terminal Developer OPEN DATABASE ? command.

This functionality is also supported by the PACK DATABASE, REBUILD DATABASE and REINDEX DATABASE commands.

Databases can also simplify data access for Recital Client Drivers using the Recital Database Server: instead of specifying a starting directory, only a database name is required. The database can handle files from multiple directories and associate tables with their single index files.

Recital Universal .NET Data Provider

/////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

/////////////////////////////////////////
// sample code to call a Stored Procedure
public int CallStoredProcedure()
{
    string source = "Data Source=localhost;" +
	                "Database=southwind;" +
			"uid=?;"+
			"pwd=?";
						
	RecitalConnection conn = new RecitalConnection(source);
	...

Recital Universal JDBC Driver

import java.sql.*;
import java.io.*;
import java.net.URL;
import java.math.BigDecimal;
import Recital.sql.*;

public class jdbc_test {

  public static void main(String argv[]) {
    int i;
    ResultSet rs;
    ResultSetMetaData rsmd;

    System.out.println("Recital JDBC driver verification.");
	
    for (int ii=0; ii<1; ++ii) {
      try {
        //----------------------------------------------------------
        //-- Load the Client Driver for the
        //-- Recital Universal Application Server
        //----------------------------------------------------------
        System.out.println("Loading Recital JDBC driver.");
        new RecitalDriver();
        //-----------------------------------------------------------
        //-- The standard format of the connection URL is as follows:
        //-----------------------------------------------------------
        String url = "jdbc:Recital:" +
                     "SERVERNAME=?;" +
                     "DATABASE=jdbc_test;" +
                     "USERNAME=?;" +
                     "PASSWORD=?;" +
                     "ENCRYPTION=false";
...

Windows Recital Universal ODBC Driver

Click image to display full size

Fig 2: Recital Universal ODBC Driver DSN setup using a database.

Database Procedure Libraries

A database can have an associated procedure library, which is automatically opened when the database is opened. This way, any procedures required by the database's data files are always available. The procedure library should reside in the database's directory and be named dbc_xxx_library.prg, where 'xxx' is the name of the database. When the OPEN DATABASE command is issued, a check is made for the database procedure library and a SET PROCEDURE TO dbc_xxx_library.prg ADDITIVE issued automatically. The procedure library is in turn closed when the CLOSE DATABASES command is issued. This is particularly convenient for client/server database access.

Database Events

Issuing the OPEN DATABASE or CLOSE DATABASES command also fires a database event. Database events, like triggers for tables and forms, can have programs associated with them. The OPEN DATABASE command fires the DBC_OPENDATA event and will run a program called db_opendata.prg if one exists in the database's directory. Similarly, the CLOSE DATABASES command fires the DBC_CLOSEDATA event and runs the db_closedata.prg program. Both of these events also allow the current open or close operation to be abandoned if the associated program returns a logical false (.F.).

Information

Databases, specifically database catalogs, are an excellent place to store information about the files required by a particular application. Instead of having to search through application code to determine which tables are being used and what index keys they have, this information can be viewed in the database catalog. Database catalogs are themselves Recital tables and can be viewed and/or updated in the same way as any other Recital table. There is also a series of commands to provide information about the currently open database. DISPLAY/LIST DATABASE The DISPLAY DATABASE and LIST DATABASE commands display the database name and path, followed by the equivalent of LIST STRUCTURE INDEX and LIST DICTIONARY for each table in the database, e.g.

> open database southwind
> display database

Database Name:  southwind
Database Path:  /usr/recital-9.0/data/southwind/

Structure for database : categories.dbf
Number of data records : 8
Date of creation : 05/12/2004
Date of last update : 05/12/2004
Database encrypted : False


Field	Field Name		Type			Width	Dec	Description
    1	CATEGORYID	Numeric       	10			Category ID
    2	CATEGORYNAME	Character     	15			Category Name
    3	DESCRIPTION	Memo           	8			Description
    4	PICTURE		Memo           	8			Picture
** Total **                       42
Production DBX file: categories.dbx
  Master Index TAG: CATEGORYID
  Key: categoryid
  Type: Binary
  Len: 8
...

DISPLAY DATABASE shows the data one screen at a time, whereas LIST DATABASE is ideal for output to a file.

> open database southwind
> list database to file info.txt

DISPLAY/LIST TABLES

LIST TABLES, as we have seen above, lists all the tables from the database, giving each table's name and path. DISPLAY TABLES shows the information one screen at a time.

Maintenance

Using a database can simplify the maintenance of an application's programs, tables and indexes. Multiple files, possibly in different directories, can be targeted by a single database command.

COMPILE DATABASE

The COMPILE DATABASE command can be used to issue a COMPILE command for all program files listed in the database catalog.

// Open the database
open database myapp

// Compile all the database's programs
compile database

NOTE: Program files are added to a database using the SQL CREATE PROCEDURE command.

PACK DATABASE

The PACK DATABASE command issues a PACK command for every table in the database catalog. The PACK command is used to permanently remove any records that have been marked for deletion using the DELETE command.

// Open the database
open database southwind
// Pack all the database's tables
pack database

REINDEX DATABASE

The REINDEX DATABASE command rebuilds all the tag and single indexes in the catalog. This is the equivalent of an INDEX ON <key> TO | TAG <index> for each catalogued index key.

// Open the database
open database southwind
// Rebuild all the database's indexes
reindex database

NOTE: Using a database helps protect against a table being opened without its associated single index files also being opened. Any single index files that are included in the database catalog will automatically be opened when their table is opened via the database. If a single index appears in the database catalog, but the physical file no longer exists, it will be removed from the catalog when its associated table is next opened. All indexes, tagged indexes or single indexes, created while the database is open, are added automatically to the database catalog.

REBUILD DATABASE

The REBUILD DATABASE command is used to PACK, rebuild the index tags and refresh the contents of the database catalog file.

// Rebuild the database
rebuild database southwind

Creating and populating a database

Databases are created using the CREATE DATABASE command.

// Create new database
create database newdb

The CREATE DATABASE creates a sub-directory in the DB_DATADIR and initializes the new database's catalog file. The catalog file is given the same basename as the database and is a Recital table with a '.cat' file extension. It has a production index file with a '.cax' file extension and a memo file with a '.cam' file extension.

// Open the database
open database newdb

With the database open, the catalog file table is opened in the highest available workarea and is given an alias name of its basename preceded by an underscore, e.g. '_newdb'. Any new tables or indexes that are created will be automatically added into the catalog and form part of the database. 'Free' tables can also be manually added into a database using the SQL ADD TABLE command.

// config.db
set sql on
set sql to vfp
// end of config.db

// Create a 'free' table, with no database open
create table free1 (field1 char(10), field2 date)
// Open the database
open database newdb
add table free1

As the application runs, 'myapp' in the example above, each table that is opened is added to the database catalog. Indexes that are opened are added in the same way. Using SET AUTOCATALOG OFF, inclusion in the catalog can be restricted. Once all required areas of the application have been catalogued, the application can be updated to make use of the database commands.

Converting an existing application

The AUTOCATALOG commands can be used to automatically create a database catalog based on an existing application. The SET AUTOCATALOG TO >database< command will create the database if it does not already exist.

// Database must be closed during autocatalog process
close databases
// Specify the database
set autocatalog to myappdb
// Start the autocatalog process
set autocatalog on
do myapp
// The autocatalog process can be toggled off to exclude 
// certain parts of the application if required
// set autocatalog off

Exporting a database

The BACKUP DATABASE and RESTORE DATABASE commands have been added to simplify the process of moving applications between binary incompatible platforms. Binary files such as tables, memo files and data dictionaries must be exported to ASCII format to allow them to be transferred from one platform to another where the platforms have different binary ordering. For example, this is the case when moving files between a SUN Sparc Solaris machine and an Intel Linux machine. The BACKUP DATABASE and RESTORE DATABASE commands are extensions of the BUILD and INSTALL commands: where BUILD and INSTALL operate on a specified list of tables, BACKUP DATABASE and RESTORE DATABASE automatically handle an entire database.

// Open the database
open database southwind
// Export the database to ASCII format
backup database

The BACKUP DATABASE command goes through the database catalog, exporting each file into an ASCII format that can be handled by the RESTORE DATABASE command. The files are created in a directory with the same name as the database. This directory is a sub-directory of the directory specified in the environment variable DB_BACKUPDIR and is created automatically. By default, DB_BACKUPDIR is the 'backup' sub-directory of the Recital home directory.

// Query the DB_BACKUPDIR environment variable setting
> ? getenv([DB_BACKUPDIR])
/usr/recital/backup

Like DB_DATADIR, DB_BACKUPDIR is set in the system-wide configuration file and is read at startup to determine the home directory for database backups. Updates to DB_BACKUPDIR once a Recital process is running do not change this setting.

# profile.db/uas extract
#---------------------------------------------------
# location of directories and important files
#---------------------------------------------------
DB_BACKUPDIR="${ROI_ROOT}backup/"     ;export DB_BACKUPDIR

Once the BACKUP DATABASE command has completed, the files can be transferred to another platform, for example from Intel SCO OpenServer to IBM AIX and the RESTORE DATABASE command used to recreate the database.

// Export the database to ASCII format
// Note: the BACKUP DATABASE command operates
// on the active or specified database
$ db
> backup database southwind
> quit

// 'tar' up the files for transfer
$ cd /usr/recital/backup
$ tar cvf southwind.tar ./southwind

// Transfer the tar archive to DB_BAKUPDIR on the 
// target machine, then extract the files
$ pwd
/usr/recital/backup
$ tar xvf southwind.tar

// Rebuild the database on the target platform
// The database is automatically created 
// as a sub-directory of DB_DATADIR
$ db
> restore database southwind

Unison is a file-synchronization tool for Mac, Unix/Linux and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. 

Binary distributions for Unison can be found here.

The user manual can be found here.