Comments on: ODTUG Kaleidoscope: HOTSOS Instrumentation Library for Oracle Friends of Oracle and Java Thu, 21 May 2015 20:49:51 +0000 hourly 1 By: Anton Scheffer Tue, 21 Aug 2007 09:01:36 +0000 My remark was not meant to criticism Hotsos ILO, I just wanted to show the possibilty to use the unknown (and undocumented) procedure sys.dbms_system.ksdwrt for writing messages to the tracefile. But I agree with you, using that procedure is not the same as using a full blown instrumentation package as Hotsos ILO.

P.S. And I have already written my own (to be true, it’s a logging package which can be used for instrumentation).

By: Cary Millsap Tue, 14 Aug 2007 16:28:01 +0000 Everything that Hotsos ILO does is doable without Hotsos ILO. We’re calling only procedures that are shipped with Oracle.

However, with Hotsos ILO, look at some of the things that now you don’t have to do:

– Keep your own stack of dbms_application_info history so that you can instrument task hierarchies, not just tasks at a single level. (A lot of people who bother to learn about and use dbms_application_info don’t tidy up after themselves; when their instrumented task ends, the relic data of the instrumented task persists in v$session until either the session ends, or some other code replaces the module/action info.)

– Figure out how to separate the act of instrumenting code (done by a developer at compile-time) from the act of activating or deactivating that instrumentation (done by a DBA at run-time).

– Figure out a consistent, application-wide policy for how to use dbms_application_info, dbms_session, dbms_support or dbms_monitor (there’s an Oracle version dependency there that you don’t want developers having to deal with), or dbms_system.ksdddt and -.ksdwrt. For example, should you nest module/action name changes within timestamps, or vice versa? What kind of format should anything you write to the trace data be in.

– Have your developers learn about dbms_support/monitor, dbms_application_info, dbms_session, etc. in the first place.

– Come up with your own security scheme to protect from public abuse of potentially dangerous packages like dbms_system.

– Worry about performance-tuning your instrumentation.

We made Hotsos ILO free and open-source, so whether you use it or not, you can see for yourself exactly what’s in there. Our hope is that you’ll find it well-written enough that you won’t bother to write your own.

By: Anton Scheffer Thu, 05 Jul 2007 14:24:20 +0000 Using sys.dbms_system.ksdwrt( 1, ‘Hallo Alex’ ) you can write whatever you want to the tracefile. You don’t need HOTSOS for that.



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