Hotsos Symposium Speaker – Dave Abercrombie

Mr. Abercrombie is a returning Hotsos Symposium presenter.

Biography

Dave AbercrombieMr. Abercrombie is the Principal Database Architect at Convio, a company that he helped found about eleven years ago. Convio is an application service provider (ASP) providing fundraising, advocacy, event fundraising, web content management and email market services for large non-profits. Dave focuses on Oracle diagnostics, tuning, and design from the perspective of the application. Dave bridges the gap between the DBAs and the application developers, speaking both languages.

Mr. Abercrombie presents regularly at the Northern California Oracle Users Group (NoCOUG). Dave also has extensive experience speaking and training in-house staff on Oracle performance.

Presentation Title

End-to-End Metrics for Troubleshooting and Monitoring

Abstract

Oracle provides an API to "tag" a session with descriptive strings from your application. These tags are exposed in V$SESSION, which provides a real-time window into session activity or status. In addition, these session-level tags get copied into Oracle's diagnostics such as ASH and AWR, where they provide essential context for troubleshooting. These tags can also be used to trigger tracing events. This API is available in PL/SQL ("dbms_application_info"), JDBC ("End-to-End Metrics"), and OCI.

This presentation provides practical advice, based on years of real-world usage, to help you get the most out of this API. For example, effective use of this API requires several compromises and balancing decisions:

  • The tags should be at an appropriate level of detail: not as low as individual SQL statements (which are already known by SQL_ID), and not so high that necessary detail is lost.
  • The tags must be rather short (32, 48, or 64 characters), so brevity is important.
  • Not all tags get swept up into all diagnostic tables, so it is non-trivial to decide which ones to use.

Use of this API can help improve communication between developers and DBAs. Overhead costs of this API will also be presented.

Presentation Materials

Presentation materials are available online to attendees only. Dave's presentation slides and white paper will be available upon receipt.

Schedule

The speaker schedule is as follows: