disabling oradiag_user logging for oracle instant client

After getting the Oracle Instant Client and DBD::Oracle successfully installed, users noticed that they were getting enormous log files in oradiag_[username]/diag/clients/user_[username]/host_nnnnnn_nn , and that logging was apparently set to 16, which is full ridiculous logging. E.g. alert/log.xml had:

<msg time='2011-08-10T13:36:50.258-04:00' org_id='oracle' comp_id='clients'
type='UNKNOWN' level='16' host_id='hostname.domain.etc' host_addr='nnn.nnn.nnn.nnn'>
<txt>Directory does not exist for read/write [/usr/lib/oracle/11.2/client64/log] []
</txt>
</msg>

LAME. So lame. Following various advice, I added the following to $ORACLE_HOME/network/admin/sqlnet.ora :

TRACE_LEVEL_CLIENT = OFF
TRACE_DIRECTORY_CLIENT=/dev/null
LOG_DIRECTORY_CLIENT = /dev/null
LOG_FILE_CLIENT = /dev/null
LOG_LEVEL_CLIENT = OFF

... all apparently for nothing. However, I eventually found Oracle document 454927.1 (note: you need to be logged in to support.oracle.com for that link to work), which indicated I needed to also disable ADR (new as of client 11.2, fancy-pants xml-based logging system) using DIAG_ADR_ENABLED = OFF. THEN you are in the old logging mode, at which point your old settings to completely avoid OCI logging will work. So, sqlnet.ora should look like this:

DIAG_ADR_ENABLED = OFF
TRACE_LEVEL_CLIENT = OFF
TRACE_DIRECTORY_CLIENT=/dev/null
LOG_DIRECTORY_CLIENT = /dev/null
LOG_FILE_CLIENT = /dev/null
LOG_LEVEL_CLIENT = OFF

HOWEVER, you must make sure that users have TNS_ADMIN=/usr/lib/oracle/11.2/client64/network/admin/ (or wherever your sqlnet.ora file is). You can add the line "export TNS_ADMIN=/path/to/your/file/" to /etc/profile to set it for all your users by default. Users can override TNS_ADMIN in their ~/.bashrc file to whatever they want.

Note - why would you want to disable the Oracle Instant Client logging? Isn't logging inherently good and disabling it inherently evil?
- If your application (e.g. perl) is already catching Oracle errors.
- If your application is in production and making many requests, the I/O from the logging might slow it down to a measurable extent.

Other sources that helped me find this solution: stackoverflow.com, CERN Savannah Bugs #58917, Oracle Forums thread #959329 (only found via the CERN page - gah!).
... thanks guys!

install perl DBD::Oracle (Lesson learned: CPAN and yum don't mix)

From the many tales of woe on the web about installing perl DBD::Oracle, from "invalid lvalue in assignment" to mysterious make errors, and the pages of intricate instructions doubtfully translated from the French, I assumed that it was a long and difficult process and it was natural that I was having problems installing on 64-bit CentOS. WRONG! It can actually be easy for lazy and dumb people like me.

First, just use yum and hand-compiling. Don't add CPAN to the mix.

1. Add the rpmforge repo and the EPEL repo (see links for instructions) so that you can install perl-DBD and perl-DBI via yum.
2. Install perl-DBD and perl-DBI via yum.
3. Download and install the OCI client "basic" and "sdk/devel" packages from Oracle. Note that you might need an older version if you're connecting to an older version of Oracle. Note also that Oracle makes you log in to download this. Note also that you need both the SDK and the Basic package. I recommend getting the rpms - install with a simple rpm -Uvh .
4. Oracle puts the libraries in a wacky place, e.g. /usr/lib/oracle/11.2/client64/lib if you're using the 64-bit version of 11.2. Therefore, create a new file, e.g. oci.conf, in /etc/ld.so.conf.d/, with the library location in it, and then run (as root) ldconfig -v to add it.
5. Download the DBD::Oracle source from cpan and extract it someplace. 
6. Set some environment variables:
   

   export ORACLE_HOME=/usr/lib/oracle/11.2/client64
   export PATH=$PATH:$ORACLE_HOME/bin
   export LD_LIBRARY_PATH=$ORACLE_HOME/lib

7. Run "perl Makefile.PL -V 11.2.0" in the directory where the OCI client was extracted. Change the version number to whatever the correct version is. This avoids the "I could not determine Oracle client version so I'll just default to version 8.0.0.0" issue.
8. Run "make install".
9. You should be done!

The latest versions of the Oracle Instant Client default to making incredibly verbose logs in the user's home directories - how to disable default oradiag_user instant client logging.