APEX error: Found dead shared server

Question

Hi,
I frequently encounter an error when working with APEX. If I submit any change to APEX, fi a change on some page item, APEX asks me to whether I'd like to save the wwv_flow_accept URL. I then get a file save dialog. This doesn't happen all the time, but something like 2 out of 10 times I submit something.
Looking at the database logs, I see an entry in alert.log with this information:
<pre>
Fri May 22 17:56:36 2009
Errors in file c:\oraclexe\app\oracle\admin\xe\bdump\xe_s004_1948.trc:
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [_npierr+487] [PC:0x5F22C3] [ADDR:0x4] [UNABLE_TO_READ] []
Fri May 22 17:56:40 2009
found dead shared server 'S004', pid = (18, 1)
</pre>
Looking into the respective trace file gives me this information:
<pre>
Dump file c:\oraclexe\app\oracle\admin\xe\bdump\xe_s004_1948.trc
Fri May 22 17:56:36 2009
ORACLE V10.2.0.1.0 - Production vsnsta=0
vsnsql=14 vsnxtr=3
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
Windows XP Version V5.1 Service Pack 3
CPU : 1 - type 586, 1 Physical Cores
Process Affinity : 0x00000000
Memory (Avail/Total): Ph:727M/1511M, Ph+PgF:1181M/2133M, VA:1428M/2047M
Instance name: xe
Redo thread mounted by this instance: 1
Oracle process number: 18
Windows thread id: 1948, image: ORACLE.EXE (S004)
*** ACTION NAME:(PAGE 4311) 2009-05-22 17:56:36.625
*** MODULE NAME:(APEX:APPLICATION 4000) 2009-05-22 17:56:36.625
*** CLIENT ID:(CKH_DEV:2151496271973569) 2009-05-22 17:56:36.625
*** SESSION ID:(29.4) 2009-05-22 17:56:36.625
*** 2009-05-22 17:56:36.625
ksedmp: internal or fatal error
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [_npierr+487] [PC:0x5F22C3] [ADDR:0x4] [UNABLE_TO_READ] []
Current SQL statement for this session:
COMMIT
----- PL/SQL Call Stack -----
object line object
handle number name
267D174C 1275 package body APEX_030200.WWV_FLOW
267D174C 5421 package body APEX_030200.WWV_FLOW
267D174C 13366 package body APEX_030200.WWV_FLOW
26521088 30 anonymous block
----- Call Stack Trace -----
memory dump follows
</pre>
Has anybody an idea what is going wrong on my machine here?
Best regards,
Jürgen

Answer 1

Hi,
I took a bit of time to dig deeper into this issue. I came to the conclusion that there is a bug in Oracle XE:
If you connect to Oracle XE database using the EPG path and if you create a report that gets its data over a database link, the shared server processes used to connect to the database break.
What I did to produce this error:
I installed Oracle XE Universal Edition on a Windows XP system
I then updated APEX to the latest version 3.2
At the database I simply created a database link pointing to the same schema the APEX-application is running at. I tested the database link.
I then produced a simple test application with just one Report (I also tried a PPR-report with the same result) that displays orders with a query in line with this:
<pre>
select o.order_id, i.order_item_id, i.quantity, p.product_name, i.unit_price, i.unit_price * i.quantity amount
from demo_orders@ckh o, demo_order_items@ckh i, demo_product_info@ckh p
where o.order_id = i.order_id
and i.product_id = p.product_id
order by o.order_id, i.order_item_id
</pre>
When I ran this application, I was sometimes able to see the report without an error, sometimes a shared server process broke. You can watch the processes breaking by opening the admin/bdump directory and see how the database writes trace files for the shared server processes.
Interesting to see is that the error happens not only when you try to see the report. If you hit the edit page link while running the page or if you submit the page definition with the link query in it, the same is likely to happen. You can see this error happening when APEX offers you to download the call to wwv_flow or the f-procedure. The contents of this download then is:
<pre>IBMPC/WIN_NT-8.1.0</pre>
with some binary information in front of the message.
Another bug I'd like to add came up when I was lucky to see the report with the PPR-template. I tried pagination but this wouldn't work. Looking into this, I found the following link:
<pre>
javascript:html_PPR_Report_Page(this,'R2060428410112776','javascript:$a_report('2060428410112776','16','15','15');')
</pre>
To my understanding this can't work at all if you look a the apostrophes. So how to proceed with this???
This to me is a severe problem, as I wanted to utilize APEX as a frontend for a production database to report the contents. I was informed by Varad that a way around this is to use an Apache access to Oracle XE but as far as I'm informed, this forces me into a licenced version in order to be able to run mod_plsql.
I read about the mod_owa-approach, but the programmers state that this is not compatible with APEX. So my question is: Do you have any suggestion on how to proceed with this?
Thanks,
Jürgen
Edited by: j.sieben on May 27, 2009 5:41 PM