#### Log panel

Logs can help you find out the reasons of problems, track down the workflow of a business process, and debug trivial messages. Options for configuring JReport Server logs have been provided in this panel. You can configure settings for each log category. After you select a log type, all the other options in the panel are used to define the log type. See the panel.

The options in the Log panel are listed as follows:

Log Type

Specifies the log category. It can be specified as one of the following:

- Engine
  Uses the "Engine" log if you want to log the events related to running reports, that is creating report results or exporting reports. Reports are run by the Engine component of JReport Server.
- Page Report
  Uses the "Page Report" log if you want to log the events related to end users modifying and saving page reports, including Ad Hoc and analysis features supported by Page Report Studio.
- Access
  Uses the "Access" log if you want to log which users accessed which services, such as report running service and task scheduling service.
- Manage
  Uses the "Manage" log if you want to log the events related to modifying settings in the Administration Console or server.properties.
- Error
  Uses the "Error" log if you want to log errors in any of the categories.
- Event
  Uses the "Event" log if you want to log the events related to the lifecycle of the server instance, such as its start time and stop time.
- Debug
  Uses the "Debug" log if you want to log the events most likely needed for debugging purposes, such as the exact SQL statements used to query the database.
- Performance
  Uses the "Performance" log if you want to analyze the performance of report result or export operations.
- Dump
  Uses the "Dump" log if you want to log events related to at what time what action is started or ended during the process of running tasks. For example, when the task is submitted, when the task is run, when the Engine is initiated, and when the Engine is stopped.

Descriptions

Displays the brief description of the specified log type.

Trace Level

Used for logging something expectable or regular, such as tracing program workflow, logging runtime information and associated elements.

You can set the trace level of the specified log type to one of the following:

- OFF
  Specifies not to use the trace level.
- OUTLINE
  The OUTLINE level specifies an outline of program workflow, and dump global variables, including a single thread, multiple threads, the time for when to begin to fetch data, and success in exporting to the specified result format.
- INFO
  The INFO level specifies informational messages that highlight the application progress at a coarse-grained level, and important local variables, such as query, parameter, formula value used when running reports, connection information, and SQL statement.
- TRIVIAL
  The TRIVIAL Level specifies fine-grained informational events most useful in tracing an application. Such as the report structure dump, or the result set dump.

Error Level

Used for logging something unexpected or irregular. For example, a URL is unreachable, a file is not there, or a table cannot be found in a data source.

You can set the error level of the specified log type to one of the following:

- OFF
  Specifies not to use the error level.
- FATAL
  The FATAL level specifies severe error events that will presumably lead the application to abort, for example, failing to read the valid key, and exceptions that result in feature uncompleted.
- ERROR
  The ERROR level specifies error events that may allow the application to continue running, such as failing to load a report, failing to find a catalog file, failing to parse a parameter, and failing to create db buffer.
- WARN
  The WARN level specifies potentially harmful situations, such as failing to find the resource, or having found invalid query or formula with grammar error when loading a catalog.

Additivity

Determines the inheritance of the appenders defined by the Logger's ancestors.

Log Destination

Specifies where the log contents will be outputted to.

If you have set log destination, the threshold level for each goal appender defines the basic log level which will be further filtered by JReport trace level and error level, and then comes out the final log output. Trace level and error level are JReport specific log levels developed based on Log4J. They group log information into two categories and add more levels to classify log information.

For example, if threshold=OFF, the trace level and error level will be ignored, and the log information output is none. If threshold=ALL, the output is determined by the trace level and error level. If threshold=one of the other levels, the output will be the result based on the trace level and error level that filter the threshold level.

- File
  Outputs log contents to the file appender that requires a layout. Logs of the specified category are written into a file. When File is checked, the following options are available:
  - Threshold
    Defines the appender's level (Log4j named as threshold).
  - Layout Type
    Specifies the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - File Name
    Specifies the name of the log file to which the File Appender will output the log contents. The suffix of the log file name is .log.
  - Append
    Specifies whether or not to retain the old contents of the specified file.
  - Buffered IO
    Specifies to create a buffer for the log IO.
- Rolling File
  Outputs log contents to the rolling file appender that requires a layout. When Rolling File is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Layout Type
    Describes the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - File Name
    Specifies the name of the log file to which the appender will output the log contents. The suffix of the log file name is .log.
  - Append
    Specifies whether or not to retain the old contents of the specified file.
  - Buffered IO
    Specifies to create a buffer for the log IO.
  - Maximum File Size
    Decides the maximum file size of the rolling file appender. The log system will create a new rolling file when the file size exceeds the maximum file size.
  - Maximum Backup Index
    Decides the maximum number of the latest rolling files that will be retained by the log system.
- Daily Rolling File
  Outputs log contents to the daily rolling file appender that requires a layout. When Daily Rolling File is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Layout Type
    Specifies the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - File Name
    Specifies the name of the log file to which the appender will output the log contents. The suffix of the log file name is .log.
  - Append
    Specifies whether or not to retain the old contents of the specified file.
  - Buffered IO
    Specifies to create a buffer for the log IO.
  - Date Pattern
    Specifies the data pattern used to generate the daily rolling file.
- Socket
  Outputs log contents to a remote log server. The socket appender needs not a layout. When Socket is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Remote Host
    Specifies the host name where the Socket Server is located.
  - Port
    Specifies the port number on which the Socket Server listens.
  - Delay
    Specifies the timeout interval value for when a client attempts to create a socket connection.
  - Location Information
    Specifies whether or not to output the log location information to the socket stream.
- NTLog
  Outputs log contents to the NT event log system. Applies only to Windows servers. This appender requires a layout. When NTLog is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Layout Type
    Specifies the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - Source
    Specifies the source name used and displayed by the NTEvent Viewer.
- Syslog
  Outputs log contents to a remote syslog daemon. Applies only to Unix and Linux servers. This appender requires a layout. When Syslog is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Layout Type
    Specifies the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - Syslog Host
    Specifies the host name where the Syslog server is located.
  - Facility
    Specifies the facility name that is used by the Syslog.
  - Facility Printing
    Specifies whether or not to print the facility information.
- LF5
  Outputs log contents to a swing based logging console. LF5 has a swing-based UI to view all of the logging messages at runtime and enables you to search and filter logging messages. This appender needs not a layout.

  When LF5 is checked, the following option is available:

  - Threshold
    Defines the appender's level.
- Telnet
  Outputs log contents to a read-only socket. You use telnet to connect to the socket and receive log data, and this is handy for remote monitoring, especially when monitoring a servlet. This appender requires a layout.

  When Telnet is checked, the following options are available:

  - Threshold
    Defines the appender's level.
  - Layout Type
    Specifies the layout type used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - Port
    Specifies the port number on which Telnet listens.
- Console
  Outputs log contents to the standard stream of Jave console. When Console is checked, the following options are available:
  - Threshold
    Defines the appender's level.
  - Layout Type
    Specifies the layout type that is used to format the log contents.
  - Pattern Conversion
    Sets the conversion pattern for the Pattern Layout.
  - Target
    Specifies the standard IO target of the Console.
    - System.out
      If selected, the log contents will be outputted to the standard output stream of the console.
    - System.err
      If selected, the log contents will be outputted to the standard error stream of the console.

Save

Applies all changes to JReport Server.

Notes:

- The Pattern Conversion option is available only when the Pattern is chosen as the Layout Type.
- For more information about the Pattern Conversion option, see comments in the LogConfig.properties file located in `<install_root>\bin` directory.