Using Trace Files to Troubleshoot Streams

SQLstream s-Server uses the standard Java logging interface (defined in the package java.util.logging) to trace execution for debugging purposes. Trace files can let you troubleshoot stream functioning during development.

Trace files are useful in troubleshooting streams, because they allow you to see when a stream failed and why.

s-Server has two trace logs. The first will be the most useful in troubleshooting streams.

  • Trace.log This is the “master” trace, which includes all trace information for the entire server. It is located at /var/log/sqlstream/Trace.propertiesTrace.log.
  • ApplicationTrace.log This contains only trace information relevant to installed application components (such as plugins, user-defined transforms, and SQL statements). It is located at /var/log/sqlstream/Trace.propertiesApplicationTrace.log.

Note: All errors that are logged to the trace log are also available in a system management stream called sys_boot.mgmt.all_trace. The latest (up to 1000) error messages are also available in a table called sys_boot.mgmt.saved_trace. You can use these to create visualizations of errors; they can be accessed from SQLline or anywhere that has a JDBC connection to s-Server. See the Global Error Stream for more details.

These logs may also be useful.

  • Console.log. A timestamped console.log is located in /var/log/sqlstream/console.log
  • Syslog. The syslog for your system may also provide useful information on s-Server.