PowerPointpresentatie

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PTW-043 Dynamic Debugging In OpenEdge
Peter van Dam pvd_at_netsetup.nl
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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Dynamic Programming

• Dynamic Windows, Frames Widgets
• Dynamic Browses
• Dynamic Buffers Queries
• Dynamic Temp-Tables
• Objects, Handles, Methods Attributes
• AppServer
• WebClient

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Memory leaks

• Show up after a long time
• Can be extremely difficult to track down (until
  now)

Bites you at deployment!
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Memory leaks

• Dynamic objects arescoped to the session
• You are responsible fordeleting objects when you
  are done with themDELETE OBJECT
  hBuffer.hBuffer ?.
• Use VALID-HANDLE in your code

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Memory leak example

• / countcust.p /
• DEF VAR hQuery AS HANDLE NO-UNDO.
• DEF VAR hBuffer AS HANDLE NO-UNDO.
• DEF VAR iCount AS INTEGER NO-UNDO.
• CREATE BUFFER hBuffer FOR TABLE "customer".
• CREATE QUERY hQuery.
• hQuerySET-BUFFERS(hBuffer).
• hQueryQUERY-PREPARE("FOR EACH customer
  NO-LOCK").
• hQueryQUERY-OPEN().
• hQueryGET-FIRST().
• DO WHILE hBufferAVAILABLE
• iCount iCount 1.
• hQueryGET-NEXT().
• END.
• MESSAGE iCount "customers found" VIEW-AS
  ALERT-BOX.

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Memory leak example

• / countcust.p /
• DEF VAR hQuery AS HANDLE NO-UNDO.
• DEF VAR hBuffer AS HANDLE NO-UNDO.
• DEF VAR iCount AS INTEGER NO-UNDO.
• CREATE BUFFER hBuffer FOR TABLE "customer".
• CREATE QUERY hQuery.
• hQuerySET-BUFFERS(hBuffer).
• hQueryQUERY-PREPARE("FOR EACH customer
  NO-LOCK").
• hQueryQUERY-OPEN().
• hQueryGET-FIRST().
• DO WHILE hBufferAVAILABLE
• iCount iCount 1.
• hQueryGET-NEXT().
• END.
• MESSAGE iCount "customers found" VIEW-AS
  ALERT-BOX.

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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The new Debugger

• A brand new Debugger was introduced in OE 10
  (actually 9.1D05)
• You must enable the Debugger in OE10

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Enabling the Debugger in OE10
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The Open Edge 10 Debugger

• The new Debugger now also allows you to trace
  memory leaks
• Use the debugalert startup parameter to invoke
  it from any message box (demo)
• Or start from the 4GL (demo)
• Or attach to a process (demo)
• Trace a memory leak (demo)
• Inspect dynamic properties (demo)

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Checking memory leaks in 4GL

• New in OE10 SESSIONFIRST-QUERYhQuery
  SESSIONFIRST-QUERY.DO WHILE VALID-HANDLE(hQuery)
  ASSIGN iQueries iQueries 1. hQuery
  hQueryNEXT-SIBLING.END.
• SESSIONFIRST-BUFFER already in 9.1B
• Demo countcustmemcheck1.p

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Getting more info from the 4GL

• Remember if you have the handle of an object,
  you can query its attributes
• For example, for a BUFFER you can find the table
  name
• For a QUERY you can find the PREPARE-STRING
• Tip use the NAME and PRIVATE-DATA attributes to
  identify dynamic objects
• Demo countcustmemcheck2.p

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What can you check in the 4GL

• Dynamic BUFFERS and TEMP-TABLES
• Dynamic QUERIES
• Dynamic DATASETS and DATA-SOURCES
• SERVERS and SOCKETS
• PERSISTENT PROCEDURES
• Non-modal WINDOWS
• Demo countcustmemcheck3.p

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What is still missing in the 4GL

• SESSIONMEMORY-SIZE
• SESSIONFIRST-WIDGET-POOL
• WIDGET-POOLFIRST-OBJECT

Just as well, because all the fun would be gone!
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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Enhanced logging in OE 10

• In Open Edge 10 the LOG-MANAGER system handle was
  introduced
• You can use it dynamically to log resources and
  events in detail
• The most important attributes for dynamic
  debugging are LOGFILE-NAME and LOG-ENTRY-TYPES

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LOG-MANAGERLOGFILE-NAME

• You can only set LOG-MANAGERLOGFILE-NAME once
  per session
• So you cannot change log files during the session
• Regrettably it is also not possible to clear the
  log file during the session

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LOG-MANAGERLOG-ENTRY-TYPES

• There are many log entry types
• You can set and unset them during the session
• Each log entry type can have different logging
  levels
• I created the Dynamic Debugging Logging
  Settings window to add to your PROTools palette

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Dynamically SettingLog Entry Types and Logging
Levels
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Using enhanced logging

• Demo Switch on the Dynamic Database Objects
  logging type, set the level to 3 or 4 and run
  countcust.p again
• The log file will show that a dynamic BUFFER and
  dynamic QUERY object are created in an unnamed
  widget pool but not deleted

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Other useful Log Entry Types

• 4GLTrace turns on logging for all RUN, FUNCTION,
  PUBLISH and SUBSCRIBE statements.
• Dynamic UI Objects tells you where dynamic
  widgets are created and deleted in your
  application. Example Track down error 4025
  (Unable to realize widget).

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Query logging

• Query Information adds very detailed information
  on dynamic queries. Example track down all
  WHOLE-INDEX queries in your application.
• You can also log information from individual
  queries by settinghQueryBASIC-LOGGING
  TRUE.Demo countcust4.p

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Event logging

• Printable Character Events logs all events
  concerning printable characters.
• Non-printable UI Events logs events concerning
  non-printable characters and WM GUI events.
• Other Events logs COM, Async and Sockets events

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Analyzing Dynamic Queries

• You can gather information on your dynamic
  queries using the Query Information Log Entry
  Type
• During development it would be nice if you could
  analyze your dynamic queries interactively
• Marius Fiere wrote a Query Tester for this purpose

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Dynamic Query Tester

• Publish your QUERY-PREPARE strings
  forinterception by the Query TesterPUBLISH
  QUERY (hQueryPREPARE-STRING).
• Press the Full Test button for live analysis
• Demo run countcust3.p

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Dynamic Query Tester results

• The Query Tester makes clever use of Dynamic
  Queries and VSTs (IMHO better information than
  DynObjects.DB Logging)
• The analysis shows that this query cannot use an
  index
• The Query Tester traps this problem although the
  performance is fine in the development environment

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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Dynamic Temp-table memory leaks

• Dynamic temp-tables aremost likely to cause
  memory leaks
• OUTPUT TABLE-HANDLES are created in the SESSION
  WIDGET-POOL (whether you like it or not)
• You need to delete those explicitly

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2 dynamic temp-table memory leaks
OUTPUT TABLE-HANDLE
CREATE TEMP-TABLE
DB
tt-leak1.p
tt-leak2.p

• tt-leak2.p contains a CREATE TEMP-TABLE statement
  that creates the TEMP-TABLE in the current
  WIDGET-POOL
• The temp-table received by tt-leak1.p is created
  in the SESSION WIDGET-POOL

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LOG-MANAGER information

• Demo Switch on Dynamic Database Objects logging
  and run tt-leak1.p
• The log shows that the following objects are
  created but not deleted

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Dynamic Temp-Table Viewer

• Lets you examine dynamic temp-tables in memory
• Download tool from www.v9stuff.com
• It shows only one memory leak
• Can you explain why?
• Can you find out how?

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Agenda

• Creating memory leaks in the 4GL
• The new Debugger
• Checking for memory leaks in 4GL
• Enhanced logging in OE10
• Dynamic Query Tester
• Dynamic Temp-table Viewer
• Dynamic AppServer debugging

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AppServer Debugging

• Enhanced Debugging is also available in AppServer
  environments
• Logging information is written to the normal log
  files
• When you hunt for memory leaks, you sometimes
  want to inspect the memory of these remote
  Progress sessions
• You can do this by splitting the memory checker
  in a client part and a server part

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Checking AppServer memory
Getappsmeminfo1.p
Getappsmeminfo2.p
DB
(Web)Client
AppServer

• The AppServer program takes a snapshot of
  AppServer memory usage and returns the result to
  the client for further processing

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Publishing debug information

• Instead of adding and removing debug messages in
  your code, you can PUBLISH the information
• At any point in time you candecide to subscribe
  to it andprocess the information
• This could mean display on aclient, write to a
  log file on theserver, analyze etc.
• I use standard debug levels Demo

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The new Debugger

• In OpenEdge 10.0B you can now also attach the
  debugger to an AppServer process anywhere on your
  network!

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Conclusion

• Open Edge 10 provides you with a spectrum of
  tools that can help you troubleshoot dynamic
  programs
• More capabilities have been added to the 4GL for
  this but there are always wishes left
• Start exploring the new Debugger
• Using handles, VSTs and pub/sub you can write
  your own tools

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More information

• Progress documentation
• OpenEdgeTM Development Debugging and
  Troubleshooting
• OpenEdgeTM Development Progress 4GL Handbook
  (John Sadds latest book)
• All example programs and tools used in this
  presentation are included on your conference CD
• www.v9stuff.com
• Progressions magazine (www.wss.com)
• Progress Email Group (www.peg.com)

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Question time