Virtual DataPort Monitors

There are three monitors specific to Virtual DataPort servers:

  • Virtual DataPort Queries Monitor. It logs all the statements processed by Virtual DataPort. It is specific to Virtual DataPort and cannot be used to monitor other Denodo servers.

    The output is logged to denodo-monitor/logs/vdp-queries.log.

    It collects information about regular queries (i.e. SELECT and CALL) and DDL statements (i.e. CREATE TABLE, CREATE VIEW, DROP TABLE, etc.), CREATE USER, CONNECT, CLOSE, etc.

  • Virtual DataPort Cache Monitor. It logs the activity of the processes that load the Virtual DataPort cache. The output is logged to denodo-monitor/logs/vdp-loadcacheprocesses.log.

  • Virtual DataPort Connections Monitor. It logs information about opened and closed connections, user account that opened/closed the connection, the interface it used (JDBC, ODBC, web service, etc.), from which IP, etc.

  • Virtual DataPort Data Sources Monitor. Every number of seconds (determined by the interval property), it logs information about all the data sources of the Virtual DataPort server.

Logging Headers

Every time the Denodo Monitor starts monitoring or has to acquire a new connection to the server, the following header is included in the logs generated by the Server and Virtual DataPort monitors:

Logging started at: 2017-02-03T15:29:17.411. Denodo Monitor started at: 2017-02-03T15:29:16.925. VDP Server started at: 2017-02-03T14:36:24.260

This header provides timestamp information about:

  • Logging. Instant when the monitor started logging. It is different among monitors due to their different polling intervals.
  • Denodo Monitor. Instant when the Denodo Monitor started monitoring. It is the same value for all the monitors.
  • Virtual DataPort Server. Instant when Virtual DataPort Server was launched.

When the logs contain several logging headers, you can detect important events by comparing their values:

  • If Virtual DataPort Server start time changes, then Virtual DataPort Server was restarted.
  • If Denodo Monitor start time changes, then Denodo Monitor was restarted.
  • If both dates remain the same, then the connection with the server was lost.