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.

Recital 10 introduced a FOREACH command, much like PHP and some other languages. This simply gives an easy way to iterate over arrays. foreach works on arrays and objects, and will issue an error when you try to use it on a variable with a different data type or an uninitialized variable. There are two syntaxes; the second is a minor but useful extension of the first:

FOREACH array_expression AS value
    statements...
ENDFOR

FOREACH array_expression AS key => value
    statements...
ENDFOR

The first form loops over the array given by array_expression. On each loop, the value of the current element is assigned to value and the internal array pointer is advanced by one (so on the next loop, you'll be looking at the next element).
The second form does the same thing, except that the current element's key will be assigned to the variable key on each loop. This form works only on associative arrays and objects.

After split brain has been detected, one node will always have the resource in a StandAlone connection state. The other might either also be in the StandAlone state (if both nodes detected the split brain simultaneously), or in WFConnection (if the peer tore down the connection before the other node had a chance to detect split brain).

At this point, unless you configured DRBD to automatically recover from split brain, you must manually intervene by selecting one node whose modifications will be discarded (this node is referred to as the split brain victim). This intervention is made with the following commands:

# drbdadm secondary resource 
# drbdadm disconnect resource
# drbdadm -- --discard-my-data connect resource

On the other node (the split brain survivor), if its connection state is also StandAlone, you would enter:

# drbdadm connect resource

You may omit this step if the node is already in the WFConnection state; it will then reconnect automatically.

If all else fails and the machines are still in a split-brain condition then on the secondary (backup) machine issue:

drbdadm invalidate resource

STRERROR()

Syntax

STRERROR( [ <expN> ] )

Description

The STRERROR() function returns a string describing the last operating system error message. If the optional error number is specified then the related operating system error message will be returned.

Example

mqdes=mqcreate("/myqueue", 2)
 if (mqdes < 0)
     messagebox(strerror()+",errno="+alltrim(str(error())))
    return
 endif
 rc = mqsend(mqdes, "Test message")
 if (rc < 0)
     messagebox(strerror()+",errno="+alltrim(str(error())))
    return
 endif
 mqclose(mqdes)