Copyright © 2013 Apex Evangelists

Troubleshooting APEX ApplicationsNienke Gijsen en Roel Hartman

About Roel

• Director of APEX Evangelists NL

• 20+ years of Oracle Experience

• “RoelH” in the APEX Forum

• Presenter at KSCOPE, OOW, Collaborate, DOAG, UKOUG, ...

• Oracle ACE Director

• Blog @ http://roelhartman.blogspot.com

• Twitter : @RoelH

Enterprise Manager

Alert.log

• Twee tot drie keer per week

• Apex process

• ORA-04030: out of process memory when trying to allocate 82456 bytes (pga heap,control file i/o buffer)

• ORA-04030: out of process memory when trying to allocate 16328 bytes (koh-kghu sessi,pmucalm coll)

Trace FilePRIVATE HEAP SUMMARY DUMP

15 GB total:

15 GB commented, 183 KB permanent

81 KB free (0 KB in empty extents),

15 GB, 1 heap: "session heap "

declare

rc__ number;

simple_list__ owa_util.vc_arr;

complex_list__ owa_util.vc_arr;

begin

owa.init_cgi_env(:n__,:nm__,:v__);

htp.HTBUF_LEN := -1;

null;

null;

simple_list__(1) := 'sys.%';

simple_list__(2) := 'dbms\_%';

simple_list__(3) := 'utl\_%';

simple_list__(4) := 'owa\_%';

simple_list__(5) := 'owa.%';

simple_list__(6) := 'htp.%';

simple_list__(7) := 'htf.%';

simple_list__(8) := 'wpg_docload.%';

if ((wwv_flow_epg_include_modules.authorize('wwv_flow_file_mgr.get_file') = false) or (owa_match.match_pattern(p_string =>

'wwv_flow_file_mgr.get_file'

MetalinkPLSQL Procedure Causing ORA-04030: (pga heap,control file i/o buffer) And ORA-04030: (koh-kghu sessi,pmuccst: adt/record) or ORA-04030: (koh-kghucall ,pmucalm coll) Errors [ID 1325100.1]

Solution

• Change the page count at the OS level:

• $ more /proc/sys/vm/max_map_count$ sysctl -w vm.max_map_count=262144 (256K)

Apex Developers

• Error log

• Tijdstippen onderzoek

• Wat doet de get_file?

• Wat kan er 16GB groot zijn?

En  nu?

DBA

Troubleshooting APEX Applications

Debugging Tracing Logging

Debugging APEX Applications

Debugging APEX Applications

• Develop Mode

• Runtime Mode

• Websheets needs a Development environment !

• @apxdvins.sql / @apxdevrm.sql

Debugging Enable - Develop Mode

• Application Level Setting

Debugging Enable - Runtime Modebegin

wwv_flow_api.set_security_group_id(p_security_group_id=>2616513429239104);! !

wwv_flow_api.set_enable_app_debugging(103,1);

end;Workspace ID

Application ID 1 = ON0 = OFF

Debugging - Develop Mode

Debugging - Runtime Mode

LEVEL1 .. LEVEL9

Debugging - Instrumentation

apex_debug

Remote Debugging

• Using SQL Developer

Tracing APEX Applications

Tracing Enable - Develop Mode

• Workspace Level Setting (default “Yes”)

Tracing Enable - Runtime Modebegin apex_instance_admin.set_parameter( p_parameter => 'TRACING_ENABLED' , p_value => 'Y' );

end;

SYS, SYSTEM, APEX_040200 or APEX_ADMINISTRATOR_ROLE

Tracing - Develop & Runtime Mode

DEBUGGING must be enabled as well!

Logging APEX Applications

Logging Enable - Develop Mode

• Workspace Level Setting (default “U”)

• Application Level Setting (default “Yes”)

Logging Enable - Runtime Mode

• Workspace Level Setting (default “U”)begin

apex_instance_admin.set_parameter( p_parameter => 'APPLICATION_ACTIVITY_LOGGING' , p_value => 'U' ); -- or [A]lways, [N]everend;

• Application Level Setting (default “Yes”)begin

wwv_flow_api.set_security_group_id(p_security_group_id=>2616513429239104);!wwv_flow_api.set_logging(103,‘YES’); -- Or ‘NO’ to switch it off

end;

Logging - Where Is It Going?SELECT apex_view_name, comments FROM apex_dictionary where column_id = 0 AND apex_view_name LIKE '%LOG%'

•

Logging - How Long Is It In There?

• Workspace Level Setting

• Develop Mode

• Runtime Mode

begin apex_instance_admin.set_log_switch_interval ( p_log_name in 'ACTIVITY' -- or ‘ACCESS’, ‘CLICKTHRU’, ‘DEBUG’

, p_log_switch_after_days => 180 ); -- between 1 and 180, default 14 end;

• Rotating Logs

Logging Examining - Develop Mode

Logging Examining - Runtime Modeselect application_id, page_id, to_char(view_date, 'DD-MM-YYYY HH24:MI') datetime, log_context, elapsed_time, rows_queriedfrom apex_workspace_activity_logorder by elapsed_time desc

The Results

• Fluctuating Performance (avg 0.1 - max 1000 sec)

• Calls to WWV_FLOW_FILE_MGR.GET_FILE

• Used to retrieve images from the database

The Cause•SELECT ‘<img src=”#WORKSPACE_IMAGES#no_picture.jpg”>’ ...FROM <awesome join>WHERE <more or less restrictions>

• Calls WWV_FLOW_FILE_MGR.GET_FILE tons of timeto retrieve ... nothing ....

The Solution

• Moved all images (and CSS / JavaScript) to web server

• Replaced ‘<img src=”#WORKSPACE_IMAGES#no_picture.jpg”>’ with ‘<img src=”/my_img/no_picture.jpg”>’

• Now using web server caching

• Database isn’t suffering from millions of calls anymore

Copyright © 2013 Apex Evangelistshttp://apex-evangelists.com

Q & A

roel@apex-evangelists.comhttp://apex-evangelists.com