Skip to main content
Version: 1.12.6.x LTS

Logging

Log files​

The log files of nevisMeta are stored in the following directory:

/var/opt/nevismeta/<instancename>/logs/

nevismeta.log​

Contains all log messages of nevisMeta.

Configuration​

Logging is configured by using the following command:

nevismeta config log

Logging layout patterns​

The pattern of each in

RollingFile:
  - name: FILE
    fileName: "logs/nevismeta.log"
    filePattern: "log/nevismeta.log.%i"
    PatternLayout:
      pattern: "%d\{ISO8601\} %20.20c\{1\}:%-4.5L \[%-8.8X\{LoginID\}\] (%t) %-6.6p%x%X\{indent\}%m%n"
    Policies:
      SizeBasedTriggeringPolicy:
        size: 10MB
    DefaultRollOverStrategy:
      max: 10

The above example prefixes log lines with the following elements (in that order):

  • a date/time timestamp (%d),
  • the thread name (%t),
  • the trace group (%c)
  • the line number(%-4.5L)

It also indents traces (%X{indent}).

Important trace groups The following table describes the most important trace groups:

Log categoryDescription
ch.adnovumTracing of nevisMeta core code
ch.nevisTracing of Nevis subcomponents such as Ninja
ch.nevis.nevismetaTracing of nevisMeta code
ch.nevis.perfRequest performance report on trace level INFO
com.sun.jerseyDebugging of REST interface code
nevismeta.propertiesConfiguration facility, configuration dump
http.requestDebugging of HTTP requests (disabled by default)
http.responseDebugging of HTTP responses (disabled by default)
http.bodyDebugging of HTTP requests body (disabled by default)
http.sessionDebugging of HTTP sessions (disabled by default)
http.timeDebugging of HTTP timings (disabled by default)
jcan.OpTrace information about SOAP method invocations (set to INFO by default)

Syslog​

You may forward log messages to a local or remote syslog host by configuring a dedicated appender. This can replace the existing file appenders, or it can be configured in addition to them.

The original SyslogAppender delivered with log4j2 have the following limitations regarding formatting:

  • If you use RFC 5424 formatting, the implementation does not allow the prefixing of logs. Prefixes are used in Nevis setups to decode the component, log file, or instance information.
  • If you do not use RFC 5424 formatting, messages are truncated to a maximum length of 1024 bytes. This is due to the message size limit of 1024 bytes defined in RFC 5424.

To work around these limitations, you can use the SocketAppender. However, SocketAppender does not allow the configuration of the facility to be set to LOCAL3. The following points help you apply the workaround despite this limitation:

  • The facility is a prefix on the message in the format of <code>, that is decoded by syslog to a facility. You can add the facility by mapping all log levels to the same facility.
  • Note that each log severity needs a different code for the same facility. The mapping grid can be found here.
  • To send all log levels to LOCAL3, you need to define the following in the beginning of the message:
<%level{TRACE=159, DEBUG=159, INFO=158, WARN=156, ERROR=155, FATAL=153}>

Sample code:

Configuration:
  monitorInterval: 60
  Appenders:
    Socket:
      - name: "SYSLOG_SERVER"
        host: "localhost"
        port: "514"
        protocol: "UDP"
        ThresholdFilter:
          level: "INFO"
          onMatch: "ACCEPT"
          onMismatch: "DENY"
        PatternLayout:
          pattern: "<%level{TRACE=159, DEBUG=159, INFO=158, WARN=156, ERROR=155, FATAL=153}>nevisMeta/audit/default: %d\{ISO8601\} %40.40c\{1\}:%-4.5L \[%-8.8X\{LoginID\}\] (%t) %-6.6p%x%X\{indent\}%m%n"
 
...
 
  Root:
    level: TRACE
    AppenderRef:
      - ref: FILE
      - ref: SYSLOG_SERVER