Monthly Archives: May 2009

Discoverer Plus decreased interaction-performance with Sun JRE 1.6.0_03

User reported a very slow interacting on his new laptop with Discoverer Plus.  Changing tabs, opening workbook wizard e.g. Other laptops / workstation had no problems.

He was the only one who had a ‘modern’ Java version on his laptop : above 1.6.   So it had to be Java.  And that was right. Note  747189.1 is mentioning the following:

The problem does not exist with JInitiator or with Sun plugin 1.4 or 1.5 and earlier versions of 1.6

* JRE 1.6.0 – works correctly, runs with 1.5.0-like speed
* JRE 1.6.0_01 – works correctly
* JRE 1.6.0_02 – works correctly
* JRE 1.6.0_03 – here the problem is observed for the first time. The issue is then observed in all subsequent versions (e.g.,  _04, _05, _06, _07 and the new_10)

The problem does not exist when an entry for the Discoverer server exists in the local hosts file on the client PC (C:\WINDOWS\system32\drivers\etc\hosts).


Sun’s Java plug-in performs reverse DNS lookups when connecting to the Application Server. This can be observed with a network sniffer trace (Wire Shark).

There is a change in the DNS handling in Sun plug-in 1.6.0_03 and higher.

Solution:  Ensure the external facing IP address of the Discoverer server has a reverse DNS entry in the DNS server.

For example:

nslookup <IP address> must resolve to the <machinename.domainname>


nslookup <machinename.domainname> must resolve to <IP address>

An alternative or temporary solution would be to add an entry to the local PC hosts file, as described above.

–> I decided to go for the last option: local host file (one laptap for the time being). It works fine.

By |May 10th, 2009|App. Server|0 Comments|

Grid Control , ora-27102, memory needed.

Tried to prepare my – Grid Control for an upgrade to   See also .

Updated for example the shared_pool_size  as 128MB as minimum size (see below for other  recommended fixed parameter settings),  although I think it also will work while setting the sga_target. Changed the sga_max_size, shutdown, startup… unfortunately: ora-27102 – out of memory. Database couldn’t be started anymore, not even in nomount (seems logic..).   All the notes are pointing to the kernel-parameter kernel.shmall. But when I recalculate, it should be quite sufficient.

Platform: Suse 9.4, 32-bits. I’m only monitoring  for this customer about something more than hundred objects: 25 databases, some application servers, 13 hosts.

Put more memory in the machine: 8GB: Same problem. 83% of the memory appeared to be diskcache, which should be good. Solution for the moment: startup the database with no sga_max_size. Increased the sga_target with 1GB: no problem. Annoying, as I have to bounce the database when I change sga_target.
For the moment no other solution at hand.

Fixed Initalization Parameters (besides 128MB shared_pool)
job_queue_processes    10
db_block_size 8192
timed_statistics TRUE
open_cursors 300
session_cached_cursors 200
aq_tm_processes  1
compatible <currently installed Oracle Database release> (default)
undo_management AUTO
undo_retention 10800
undo_tablespace <any acceptable name>
processes 150
log_buffer 1048576
statistics_level TYPICAL (Note that this value is specific only to Enterprise Manager 10g Repository Database release and later.)
TEMP space (Tablespace)Foot 1  50 MB (extending to 100 MB)
_b_tree_bitmap_plans false (hidden parameter)

By |May 10th, 2009|grid control|0 Comments|