# Configuring a Syslog appender

You may want to send logs directly to a syslog, a syslog-ng or a rsyslog system.

## Procedure

1. Open the <RemoteEngineInstallationDirectory>/etc/org.ops4j.pax.logging.cfg file and add the following lines:
   ### Example
   ```
   log4j2.appender.syslog.type = Syslog
   log4j2.appender.syslog.name = SyslogAppender
   log4j2.appender.syslog.format = RFC5424
   log4j2.appender.syslog.host = localhost
   log4j2.appender.syslog.port = 514
   log4j2.appender.syslog.protocol = TCP
   log4j2.appender.syslog.appName = RE
   log4j2.appender.syslog.includeMDC = true
   log4j2.appender.syslog.facility = LOCAL0
   log4j2.appender.syslog.layout.type = JsonTemplateLayout
   log4j2.appender.syslog.layout.eventTemplateUri=${karaf.base.uri}/etc/jsonLogMinTemplate.json
   log4j2.appender.syslog.layout.stackTraceElementTemplateUri=${karaf.base.uri}/etc/StackTraceElementLayout.json

   log4j2.rootLogger.appenderRef.SyslogAppender.ref = SyslogAppender
   ```
2. Save the file.
3. Add the Mapped Diagnostic Context (MDC) information to the JSON template file so that the output logs, where applicable, contain the MDC information. This MDC information includes the run ID of a Talend Management Console task.
   1. In <RemoteEngineInstallationDirectory>/etc, create a configuration file and name it as jsonLogMinTemplateCustom.json.

      In this file, you configure the format of the output logs.
   2. Add the following lines to this new file to create a MDC resolver:
      ## Example
      ```
      {
         "logMessage": {
            "$resolver": "message", 
            "stringified": true
         },
         "my_mdc": { 
            "$resolver": "mdc" 
         },
         "logTimestamp": {
            "$resolver": "timestamp", 
            "epoch": {
               "unit": "millis", 
               "rounded": true
             }
         },
          "severity": {
             "$resolver": "level",
             "field": "name"
         },
          "ticLogLevel": {
             "$resolver": "source", 
             "field": "ticLogLevel"
         }
      }
      ```

      The example defines a JSON object to specify the fields to include in the MDC output. The object uses key-value pairs, where the keys represent the output fields and the values specify the resolvers to populate those fields.

      The "my\_mdc": { "$resolver": "mdc" } line creates a field called my\_mdc in the output. The mdc resolver populates this field with all MDC fields, which provide additional diagnostic information associated with the logs. A my\_mdc field can look like this:
      ```
      { 
        "accountID":"31e47fe5-abcd-4a80-a8b2-590123456789",
        "bundle.id":"289",
        "bundle.name":"org.talend.ipaas.engine.deployment-agent",
        "bundle.version":"2.13.7",
        "executionDestination":"REMOTE_ENGINE",
        "flowExecutionId":"ed31c1a8-abcd-4121-98bd-cd0123456789",
        "flowID":"61fbfc899e86410123456789",
        "flowVersion":"45.28",
        "remoteEngineId":"c62cd9a1-abcd-4580-8af1-220123456789",
        "userId":"user.talend.com",
        "workspaceId":"5ef6605b2632fd1234567890"
      }
      ```

      To retrieve specific MDC fields such as flowID (representing a task ID) and flowExecutionId (representing a task run ID), replace the "my\_mdc": { "$resolver": "mdc" } line with:
      ```
      "taskId": {"$resolver": "mdc", "key": "flowID"},
      "executionId": {"$resolver": "mdc", "key": "flowExecutionId"},
      ```

      The field names taskId and executionId are just examples. You can use any meaningful names to receive the MDC fields you want to include in the output.
4. Configure your Syslog system to use this new jsonLogMinTemplateCustom.json template instead of the default template file jsonLogMinTemplate.json.