# Enhanced WEM Logging

The WEM application is equipped with enhanced logging functionality that provides the user with the ability to:

- Dynamically change logger parameter settings in real-time through the use of text-based Extensible Markup Language (XML) configuration files.
- Tailor both the log message and log file format to meet your needs.
- Provide log messages for different severity levels.
- Filter log messages.

This chapter includes the following topics:

- Supported Components
- Configuring Appender Settings
- Configuring Logger Settings
- Configuring Log Message Filters
- Configuring Support for Dynamic Logging Updates

IMPORTANT:

Unless otherwise specified, all information in this chpater applies to both Sun Solaris- and Red Hat Enterprise Linux-based WEM systems.

Supported Components

Enhanced logging functionality is supported for the following WEM components:

- WEM Server: Logging for the server component of the WEM is facilitated by the emslogger.xml file located in the /<ems_dir>/server/etc directory by default. This component consists of a number of categories (called loggers) as described in the following table.

Table 1. EMS Server Component Logger Categories

Category | Description
--- | ---
AAARADIUS | Pertains to authentication, authorization, and accounting (AAA) functionality using the RADIUS protocol functionality.
ADHOCRPT | Pertains to ad-hoc report generation functionality
AlarmMgmtMain | Pertains to SNMP alarm management functionality.
APN | Pertains to Access Point Name (APN) functionality
CA | Pertains to Context Administration (CA) functionality.
CAT | Pertains to Config Audit Trail (CAT) functionality.
CDR | Pertains to Charging Detail Record (CDR) functionality.
CHARGINGSVC | Pertains to integrated Enhanced Charging Service (ECS) functionality.
CPU | Pertains to system Central Processing Unit (CPU) state information.
CSM | Pertains to Client Session Management (CSM) functionality.
CSP | Pertains to the system’s Card, Slot, Port (CSP) software task.
CSS | Pertains to Content Service Steering (CSS) functionality.
DB | Pertains to Data Base (DB) functionality.
DHCP | Pertains to DHCP functionality.
FM | Pertains to Fault Management (FM) functionality.
GBLCMDS | Pertains to system Global Commands (GBLCMDS) functionality.
starent-tableGGSN | Pertains to GGSN functionality.
starent-tableGTPC | Pertains to GTP Control (GTPC) functionality.
GTPP | Pertains to GTP Prime (GTPP) functionality.
IMGCACHE | Pertains to system Information Cache (IMGCACHE) functionality.
IMGKA | Pertains to system Keep-Alive (IMGKA) functionality.
IMGLicense | Pertains to system session and feature-use licensing.
Interceptor | Pertains to Client interceptor methods functionality.
IPSec | Pertains to IP Security functionality.
L2TP | Pertains to L2TP functionality.
Logs | Pertains to system log functionality.
MIP | Pertains to Mobile IP functionality.
Monitor | Pertains to Monitor functionality.
NR | Pertains to Network Reachability Server Configuration functionality.
ORBEM | Pertains to Common Object Broker Request Architecture (CORBA) functionality.
OSPF | Pertains to OSPF routing functionality.
Pdsn | Pertains to PDSN functionality.
PM | Pertains to Process Monitor (PM) functionality.
PortMon | Pertains to system port monitoring functionality.
PPP | Pertains to PPP functionality.
PS | Pertains to polling support functionality.
RP | Pertains to RP interface functionality.
ScbrSessMgt | Pertains to subscriber session management functionality.
SessionSubsystem | Pertains to the system session subsystem software.
SNMP | Pertains to SNMP functionality.
SVPN | Pertains to the system Virtual Private Network (VPN) software tasks.
System | Pertains to system functionality.
TCA | Pertains to threshold crossing alert functionality.
Topology | Pertains to Topology interface functionality.
UA | Pertains to User Administration functionality.
UCM | Pertains to Access Service Configuration (UCM) functionality.
UPref | Pertains to User Preferences functionality.
SWU | Pertains to Software Upgrade functionality.
ConfigBackup | Pertains to the Web Element Manager’s configuration backup functionality.

- Bulk Statistics Parser: Logging for the Bulk Statistic Parser component of the WEM is facilitated by the bsparserlogger.xml file located in the /<ems_dir>/server/etc directory by default. This component is responsible for analyzing information collected by the Bulk Statistic Server.
- Bulk Statistics Server: Logging for the Bulk Statistic Server component of the WEM is facilitated by the bsserverlogger.xml file located in the /<ems_dir>/server/etc directory by default. This component is responsible for collecting bulk statistic information from the system.
- Script Server: Logging for the Script Server component of the WEM is facilitated by the scriptlogger.xml file located in the /<ems_dir>/server/etc directory by default. This component supports the ability to execute specific scripts upon the receipt of SNMP alarms.
- NorthBound Server: Logging for the NorthBound Server component of the WEM is facilitated by the nbserverlogger.xml file located in the /<ems_dir>/server/etc directory by default. This component is responsible for collecting NB server information from the system.

The XML configuration file for each of the above components consists of the following configurable elements:

- Appender settings: Control log file parameters such as naming, output location, format, and sizing specifications.
- Logger settings: Control logging parameters for the specified category such as whether or not to use appender settings and the log level. As described previously, the WEM Server component consists of multiple loggers. There is a single logger for the other components.
- Root element: Contains references to other appenders that should be added to loggers contained in the XML configuration file. In addition, this element contains a parameter that dictates how often the system is to scan and incorporate changes made to the logger configuration. (Additional information on configuring the scan frequency is provided in the Configuring Support for Dynamic Logging Updates section of this chapter.)

Configuring Appender Settings

Appender settings control log file parameters such as naming, output location, format, and sizing specifications.
Appenders are defined by their class. Each class has related parameters that are configurable. The following appender classes are supported:

- Asynchronous Appender
- Console Appender
- File Appender
- Rolling File Appender
- Daily Rolling File Appender
- Socket Appender
- Telnet Appender
- SMTP Appender
- Syslog Appender

Detailed information for each of the above classes is provided in the sections that follow.

By default, each logging configuration file has a single Rolling File Appender configured called Main. Each logger within the file is configured to use this appender by default. (It is referenced in the root element in the configuration file.) Additional appenders can be added to the configuration file using a text editor (such as Vi Editor) if desired.

Asynchronous Appender Settings

Asynchronous appenders are used to log events asynchronously. It uses a bounded buffer to store logging events. A separate thread is used to serve the events in its bounded buffer.

Multiple appenders can be attached to an Asynchronous appender. In this scenario, this appender collects the events sent to it and then, dispatches them to all the appenders that are attached to it.
Asynchronous appenders have the following format:

    <appender name="appender_name" class="AsyncAppender">

       <param
    name="BufferSize" value="size"/>

       <appender-ref ref="attached_appender"/>

    </appender>

The variables identified in the format above are described in the following table.
Table 2. Asynchronous Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
size | Specifies the number of events to be stored in buffer. This is configured as a non-negative integer value. The default is 128 events.
attached_appender | The name of an appender to be attached to this appender.

Console Appender Settings

Console appenders display log events to the console display.
Console appenders have the following format:

    <appender name="appender_name" class="ConsoleAppender">

       <param
    name="Target" value="output"/>

       <layout class="layout_class">

          <param name="ConversionPattern" value="conv_pattern"/>

       </layout>

    </appender>

The variables identified in the format above are described in the following table.
Table 3. Console Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
output | Specifies the file output as either stdout or stderr. The default target is stdout.
layout_class | Specifies the format of the log file output. Refer to the Log File Output Formats section of this chapter for information on supported output formats.
conv_pattern | Specifies the conversion pattern used to format event related information. Refer to the Pattern Layout Supported Conversion Characters table for a list of supported conversion characters.

File Appender Settings

This appender adds log events to a file.
File appenders have the following format:

    <appender name="appender_name" class="FileAppender">

       <param
    name="File" value="file_name"/>

       <param
    name="Append" value="append_option"/>

       <layout class="layout_class">      <param name="ConversionPattern" value="conv_pattern"/>

       </layout>

    </appender>

The variables identified in the format above are described in the following table.
Table 4. File Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
file_name | Specifies the name of the output file.
append_option | Dictates whether log information will be appended to the file or not. This can be set to either of the following options: true : Append the information; this is the default setting. false : Do not append the information.
layout_class | Specifies the format of the log file output. Refer to Log File Output Formats section of this chapter for information on supported output formats.
conv_pattern | Specifies the conversion pattern used to format event related information. Refer to the Pattern Layout Supported Conversion Characters table for a list of supported conversion characters.

Rolling File Appender Settings

This appender type extends the File Appender capability to backup the log files when they reach a certain size. This is the default appender type.
Rolling File appenders have the following format:

    <appender name="appender_name" class="RollingFileAppender">

       <param
    name="File" value="file_name"/>

       <param
    name="Append" value="append_option"/>

       <param
    name="MaxFileSize" value="size"/>

       <param
    name="MaxBackupIndex" value="max_backups"/>

       <layout class="layout_class">

       <param
    name="ConversionPattern" value="conv_pattern"/>

       </layout>

    </appender>

The variables identified in the format above are described in the following table.
Table 5. Rolling File Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender. By default, each configuration file has a single appender configured called Main-- each logger within the file are configured to use this appender by default. Additional appenders can be added to the configuration file using the defined format. This allows you to specify an appender for each logger if desired.
file_name | Specifies the name of the output file.
append_option | Dictates whether log information will be appended to the file or not. This can be set to either of the following options: true : Append the information; this is the default setting. false : Do not append the information.
size | Specifies the maximum size (in mega bytes) a log file can reach before creating a backup file and starting a new log file. This can be configured to any integer value from 0 to (263-1). The suffixes “KB”, “MB” or “GB” so that the integer is interpreted being expressed respectively in kilobytes, megabytes or gigabytes. (For example, the value “10KB” is interpreted as 10240 Bytes.) The default value is 5MB.
max_backups | Specifies How many backup files are kept before the oldest is erased. It can be configured as a non-negative integer value. A value of 0 generates no backup files no backup files and truncates the log file when it reaches MaxFileSize. The default value is 10.
layout_class | Specifies the format of the log file output. Refer to the Log File Output Formats section of this chapter for information on supported output formats.
conv_pattern | Specifies the conversion pattern used to format event related information. Refer to the Pattern Layout Supported Conversion Characters table for a list of supported conversion characters.

Daily Rolling File Appender Settings

This appender extends the File Appender capability so that the underlying file is rolled over at a user chosen frequency. The rolling schedule is specified by the DatePattern option. A formatted version of the date pattern is used as the suffix for the rolled file name.
Daily Rolling File appenders have the following format:

    <appender name="appender_name" class="DailyRollingFileAppender">

       <param
    name="File" value="file_name"/>

       <param
    name="Append" value="append_option"/>

       <param
    name="DatePattern" value="date_format"/>

       <layout class="layout_class">      <param
    name="ConversionPattern" value="conv_pattern"/>

       </layout>

    </appender>

The variables identified in the format above are described in the following table.
Table 6. Daily Rolling File Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender. By default, each configuration file has a single appender configured called Main-- each logger within the file are configured to use this appender by default. Additional appenders can be added to the configuration file using the defined format. This allows you to specify an appender for each logger if desired.
file_name | Specifies the name of the output file.
append_option | Dictates whether log information will be appended to the file or not. This can be set to either of the following options: true : Append the information; this is the default setting. false : Do not append the information.
date_format | Specifies the date format. The following time and date options are supported: %a -- Abbreviated weekday name %A -- Full weekday name %b -- Abbreviated month name %B -- Full month name %c -- Standard date and time string %d -- Day of month as a decimal(1-31) %H -- Hour(0-23) %I -- Hour(1-12) %j -- Day of year as a decimal(1-366) %m -- Month as decimal(1-12) %M -- Minute as decimal(00-59) %p -- Locale's equivalent of AM or PM %Q -- Millisecond as decimal (000-999) %S -- Second as decimal(00-59) %U -- Week of year, Sunday being first day(0-53) %w -- Weekday as a decimal(0-6, Sunday being 0) %W -- Week of year, Monday being first day(0-53) %x -- Standard date string %X -- Standard time string %y -- Year in decimal without century(0-99) %Y -- Year including century as decimal %Z -- Time zone name %% -- The percent sign
layout_class | Specifies the format of the log file output. Refer to the Log File Output Formats section of this chapter for information on supported output formats.
conv_pattern | Specifies the conversion pattern used to format event related information. Refer to the Pattern Layout Supported Conversion Characters table for a list of supported conversion characters.

For example, if the File parameter is set to abc.log and the DatePattern parameter is set to .%Y-%m-%d, on 2001-02-16 at midnight, the logging file abc.log is copied to abc.log.2001-02-16 and logging for 2001-02-17 will continue in abc.log until it rolls over the next day.

Socket Appender Settings

This appender has the following properties:

- If sent to a Socknode, remote logging is non-intrusive as far as the log event is concerned. In other words, the event will be logged with the same time stamp, nested diagnostic Context, and location information as if it were logged locally by the client.
- Socket appenders do not use a layout. They ship a serialized LoggingEvent object to the server side.
- Remote logging uses the TCP protocol. Consequently, if the server is reachable, then log events eventually arrive at the server.
- If the remote server is down, the logging requests are simply dropped. However, if and when the server comes back up, event transmission is resumed transparently. This transparent re-connection is performed by a connector thread which periodically attempts to connect to the server.

Socket appenders have the following format:

    <appender name="appender_name" class="SocketAppender">

       <param
    name="RemoteHost" value="host"/>

       <param
    name="Port" value="port_no"/>

    </appender>

The variables identified in the format above are described in the following table.
Table 7. Socket Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
host | Specifies the host to log messages to.
port_no | Specifies the port number over which to log events.

Telnet Appender Settings

This appender specializes in writing to a read-only socket. The output is provided in a telnet-friendly way so that a log can be monitored over TCP/IP. Clients using telnet connect to the socket and receive log data. This is handy for remote monitoring, especially when monitoring a servlet.
Telnet appenders have the following format:

    <appender name="appender_name" class="TelnetAppender">

       <param
    name="RemoteHost" value="host"/>

       <param
    name="Port" value="port_no"/>

    </appender>

The variables identified in the format above are described in the following table.
Table 8. Telnet Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
host | Specifies the host to log messages to.
port_no | Specifies the port number over which to log events.

SMTP Appender Settings

This appender supports the sending of an e-mail when a specific logging event occurs, typically on errors or fatal errors.

The number of logging events delivered in this e-mail depend on the value of BufferSize option. The SMTP Appender keeps only the last BufferSize logging events in its cyclic buffer. This keeps memory requirements at a reasonable level while still delivering useful application context.
SMTP appenders have the following format:

    <appender name="appender_name" class="SMTPAppender">

       <param
    name="BufferSize" value="size" />

       <param
    name="SMTPHost" value="smtp_host"/>

       <param
    name="From" value="sender"/>

       <param
    name="To" value="recipient"/>

       <param
    name="Subject" value="subject"/>

       <layout class="layout_class">

          <param
    name="ConversionPattern" value="conv_pattern"/>

       </layout>

    </appender>

The variables identified in the format above are described in the following table.
Table 9. SMTP Appender Variable Descriptions

Variable | Description
--- | ---
appender_name | The name of the appender.
size | Specifies the maximum number of logging events to collect in a cyclic buffer. When the BufferSize is reached, the oldest events are deleted as new events are added to the buffer. The size can be configured to a non-negative integer value. The default size of the cyclic buffer is 512 events.
smtp_host | Specifies the SMTP mail server.
sender | Specifies the e-mail address of the sender.
recipient | Specifies the e-mail address of the recipient.
subject | Specifies a subject for the e-mail.
layout_class | Specifies the format of the log file output. Refer to the Log File Output Formats section of this chapter for information on supported output formats.
conv_pattern | Specifies the conversion pattern used to format event related information. Refer to the Pattern Layout Supported Conversion Characters table for a list of supported conversion characters.

Log File Output Formats

The WEM enhanced logging function provides the ability to specify the log file output format. Layout configuration is performed using the layout class parameter.

The following formats are supported:

- HTML Layout
- TTCC Layout
- Simple Layout
- Pattern Layout

Detailed information for each of the above classes is provided in the sections that follow.

HTML Layout

This layout displays events in HTML tables. For each event, the following fields are provided:

- Time: Event time
- Thread: Event thread
- Level: Event severity Level
- Category (Module): The enhanced logging function category that generated the event
- Message: Event description

Use the following parameter configuration to use the HTML Layout:

    <layout class="HTMLLayout"/>

An example of this layout’s output is shown below.
Figure 1. Sample HTML Layout

TTCC Layout

This layout consists of Time, Thread, Category, and nested diagnostic Context information. Each of these items can be individually enabled or disabled. The time format depends on the DatePattern used.

CAUTION:

Do not use the same TTCC Layout instance from within different appenders. The TTCC Layout may not handle event threads properly when used in this way.
Use the following parameter configuration to use the TTCC Layout:

    <layout class="TTCCLayout"/>

       <param
    name="DatePattern" value="date_format"/>

    </layout>

The variables identified in the format above are described in the following table.
Table 10. TTCC Layout Variable Descriptions

Variable | Description
--- | ---
date_format | Specifies the date format. The following time and date options are supported: %a -- Abbreviated weekday name %A -- Full weekday name %b -- Abbreviated month name %B -- Full month name %c -- Standard date and time string %d -- Day of month as a decimal(1-31) %H -- Hour(0-23) %I -- Hour(1-12) %j -- Day of year as a decimal(1-366) %m -- Month as decimal(1-12) %M -- Minute as decimal(00-59) %p -- Locale's equivalent of AM or PM %Q -- Millisecond as decimal (000-999) %S -- Second as decimal(00-59) %U -- Week of year, Sunday being first day(0-53) %w -- Weekday as a decimal(0-6, Sunday being 0) %W -- Week of year, Monday being first day(0-53) %x -- Standard date string %X -- Standard time string %y -- Year in decimal without century(0-99) %Y -- Year including century as decimal %Z -- Time zone name %% -- The percent sign

An example of this layout’s output is shown below.

    176 [main] INFO
     examples.Sort - Populating an array of 2 elements in reverse order.

    225 [main] INFO
     examples.SortAlgo - Entered the sort method.

Simple Layout

This layout displays the event severity level and the event description.
Use the following parameter configuration to use the Simple Layout:

    <layout class="SimpleLayout"/>

An example of this layout’s output is shown below.

    INFO  - Populating an
    array of 2 elements in reverse order.

    INFO  - Entered the sort method.

Pattern Layout

This layout allows the specification of an output format through the configuration of a pattern string. It formats the log event and returns it as a string.
Use the following parameter configurations to use the Pattern Layout:

    <layout class="org.apache.log4j.PatternLayout"/>

       <param
    name="ConversionPattern" value="pattern"/>

    </layout>

pattern specifies the conversion characters used to format the output. The following table provides information on supported conversion characters.
Table 11. Pattern Layout Supported Conversion Characters

Character | Description
--- | ---
c | Used to output the logger of the logging event. The logger conversion specifier can be optionally followed by precision specifier, that is a decimal constant in brackets. If a precision specifier is given, then only the corresponding number of right most components of the logger name will be printed. By default the logger name is printed in full. For example, for the logger name “a.b.c” the pattern %c{2} will output “b.c”.
d | Used to output the date of the logging event. The date conversion specifier may be followed by a date format specifier enclosed between braces. For example, %d{%H:%M:%S} or %d{%d %b %Y %H:%M:%S}. If no date format specifier is given then ISO8601 format is assumed.The following format options are possible: %a -- Abbreviated weekday name %A -- Full weekday name %b -- Abbreviated month name %B -- Full month name %c -- Standard date and time string %d -- Day of month as a decimal(1-31) %H -- Hour(0-23)%I -- Hour(1-12) %j -- Day of year as a decimal(1-366) %m -- Month as decimal(1-12) %M -- Minute as decimal(00-59) %p -- Locale's equivalent of AM or PM %Q -- Millisecond as decimal (000-999) %S -- Second as decimal(00-59) %U -- Week of year, Sunday being first day(0-53) %w -- Weekday as a decimal(0-6, Sunday being 0) %W -- Week of year, Monday being first day(0-53) %x -- Standard date string %X -- Standard time string %y -- Year in decimal without century(0-99) %Y -- Year including century as decimal %Z -- Time zone name %% -- The percent sign You can also use the enhanced logging function’s predefined date formatters. These can be specified using one of the following strings: ABSOLUTE : AbsoluteTimeDateFormat DATE : DateTimeDateFormat ISO8601 : ISO8601DateFormat For example, %d{ISO8601} or %d{ABSOLUTE}.
F | Used to output the file name where the logging request was issued. IMPORTANT: Generating caller location information is extremely slow. It's use should be avoided unless execution speed is not an issue.
l | Used to output location information of the caller which generated the logging event. IMPORTANT: Though location information can be very useful, it's generation is extremely slow. It's use should be avoided unless execution speed is not an issue.
L | Used to output the line number from where the logging request was issued. IMPORTANT: Generating line number information is extremely slow. It's use should be avoided unless execution speed is not an issue.
m | Used to output the application supplied message associated with the logging event.
n | Outputs the platform dependent line separator character or characters. This conversion character offers practically the same performance as using non-portable line separator strings such as “\n”, or “\r\n”. Thus, it is the preferred way of specifying a line separator.
p | Used to output the level (priority) of the logging event.
r | Used to output the number of milliseconds elapsed since the start of the application until the creation of the logging event.
t | Used to output the name of the thread that generated the logging event.
x | Used to output the NDC (nested diagnostic context) associated with the thread that generated the logging event.
% | The sequence %% outputs a single percent sign.

An example of this layout’s output when the following conversion pattern was specified is shown below:

    %d{%d:%b:%Y %H:%M:%S:%Q}%6p %3t [%-16x] %8m%n

    25:Aug:2005 13:14:27:494
      INFO   1 [main DBData::initialize] DB info initialized

Configuring Logger Settings

Loggers are configured for each of the WEM components described previously in this document. Additionally, for the WEM Server component which consists of multiple categories, loggers are configured for each of the categories.
Loggers are configured using the following format:

    <logger name="name" additivity="add_option">

       <level
    value="severity"/>

       <appender-ref
    ref="appender_name"/>

    </logger>

Table 12. Logger Variable Descriptions

Variable | Description
--- | ---
name | The name of the WEM component of category for which logging parameters are being configured.
add_option | Specifies whether or not the logger is to inherit the appenders defined within the root element of the configuration file. The following options are supported: true : Use appender defined within root (default) false : Do not use appender defined within root
severity | Specifies the severity level of events to log. The following severity levels are supported: OFF, 0 DEBUG, 1I NFO, 2 WARN, 3 SEVERE, 4 FATAL, 5 All, 6
appender_name | The name of the appender to use for this logger. IMPORTANT: This parameter is used if the additivity parameter is set to false.

Configuring Log Message Filters

Log messages can be filtered based on the following criteria:

- Level match
- Level range
- String match
- Deny filter

Detailed information for each of the above classes is provided in the sections that follow.

Level Match Filters

This filter displays or rejects logs for events that match the specified severity level.
Level Match filters are configured using the following format:

    <filter class="LevelMatchFilter">

       <param
    name="LevelToMatch" value="severity" />

       <param
    name="AcceptOnMatch" value="accept_option"/>

    </filter>

Table 13. Level Match Filter Variable Descriptions

Variable | Description
--- | ---
severity | Specifies the severity level of events to filter. The following severity levels are supported: OFF, 0 DEBUG, 1 INFO, 2 WARN, 3 SEVERE, 4 FATAL, 5 All, 6
accept_option | Specifies whether or not the logger is to accept logs that match the specified severity. The following options are supported: true : Logs matching the severity are accepted false : Logs matching the severity are not accepted

Level Range Filters

This filter displays or rejects logs for events that fall within the specified minimum and maximum severity levels.
Level Range filters are configured using the following format:

    <filter class="LevelRangeFilter">

       <param
    name="LevelMax"  value="max_sev"/>

       <param
    name="LevelMin"  value="min_sev"/>

       <param
    name="AcceptOnMatch" value="accept_option"/>

    </filter>

Table 14. Level Range Filter Variable Descriptions

Variable | Description
--- | ---
max_sev | Specifies the maximum severity level for the range of events to filter. The following severity levels are supported: OFF, 0 DEBUG, 1 INFO, 2 WARN, 3 SEVERE, 4 FATAL, 5 All, 6
min_sev | Specifies the minimum severity level for the range of events to filter. The following severity levels are supported: OFF, 0 DEBUG, 1 INFO, 2 WARN, 3 SEVERE, 4 FATAL, 5 All, 6
accept_option | Specifies whether or not the logger is to accept logs that fall within the specified severity range. The following options are supported: true : Logs matching the criteria are accepted false : Logs not matching the criteria are not accepted

String Match Filters

This filter displays or rejects logs for events based on whether or not any part of the event message matches the specified string.
String Match filters are configured using the following format:

    <filter class="StringMatchFilter">

       <param
    name="StringToMatch" value="string" />

       <param
    name="AcceptOnMatch" value="accept_option"/>

    </filter>

Table 15. String Match Filter Variable Descriptions

Variable | Description
--- | ---
string | Specifies the text string upon which to filter the log.
accept_option | Specifies whether or not the logger is to accept logs that match the specified severity. The following options are supported: true : Logs matching the criteria are accepted false : Logs not matching the criteria are not accepted

Deny Filters

This filter denies all log messages regardless of severity.
Deny filters are configured using the following format:

    <filter class="DenyAllFilter">

This can be used in conjunction with other log message filters that display logs based on the specified criteria. For example, the following configuration displays Warning-level logs and denies all others:

    <filter class="LevelMatchFilter">

       <param
    name="LevelToMatch" value="WARN" />

       <param
    name="AcceptOnMatch" value="true"/>

    </filter>

    <filter class="DenyAllFilter">

Configuring Support for Dynamic Logging Updates

A key benefit of the WEM’s logging functionality is the ability to dynamically incorporate changes made to the logging configuration without restarting server processes.

The WEM periodically checks the XML configuration files for changes. If the changes are found, they are automatically applied.
Each XML configuration file contains a parameter called delay value that is used to specify the frequency with which the server looks for changes. This parameter is defined under the root element as shown below:

    <root>

        <priority value="WARN"/>

        <!-- A delay used
    by the Watchdog thread to continuously read/check

        the modified configuration
    applies to EMS Logger-->

        <delay value="3000"/>

        <appender-ref
    ref="Main"/>

    </root>

The delay is measured in milliseconds (ms). The default value is 3000 ms.