1. Memory Management in SharePoint 2007 Development Matt Vignau Liquid Hub, Inc www.liquidhub.com [email_address]

3. Working with SharePoint since SP 2003

4. Work for Liquid Hub

5. User Group speaker

7. No more destructors

8. SPSite and SPWeb not always disposed

9. Leaves growing used memory block

10. Leads to problems

12. Application Pool limitations

13. 64 bit vs 32 bit

15. Memory is reserved in chunks – like number of diners

16. Memory wants to “sit together”

18. SPSite and SPWeb sites have ~2kB size wrappers

19. Object sizes are closer to 1-2 MB

20. One site with 15 webs accessed twice has used around 30 MB of system memory; for *one* user

21. Can bring down entire farms

22. Running in Debug mode

23. /3 GB switch – Doesn't work in SharePoint!

24. Example 1 public void GetNavigationInfo() { SPWeb OurWeb = http://intranet.litwareinc.com; foreach( SPWeb OurWeb in OurWeb .GetSubWebsForCurrentUser()) { //Our Subsite code here } }

26. Does the entire system crash or users receive “Page not available”?

27. Does the system use custom webparts or third party webparts?

28. Are you running multiple applications from the same app pool?

29. Does the ULS log state “Potentially excessive number of SPRequest threads currently unreleased”?

30. Was any compiled code released in debug mode?

31. Example 2 public void GetNavigationInfo() { SPWeb OurWeb = http://intranet.litwareinc.com; foreach( SPWeb OurWeb in OurWeb.GetSubWebsForCurrentUser()) { //Our Subsite code here OurWeb.Dispose(); } }

32. Example 3 pt 1 try { SPSite OurSiteObject; SPWeb OurObject; //our main code body here }

33. Example 3 pt 2 catch { //Our exception handling code }

34. Example 3 pt 3 finally { if(OurObject != NULL) { OurObject.Dispose(); } if(OurSiteObject != NULL) { OurSiteObject.Dispose(); } }

36. Finally block executes the dispose after the code block is complete to avoid problems

37. No explicit calls to dispose necessary for SPContext initializations*

39. Single block usage with automatic disposal

40. No additional call out to the dispose method is needed

41. Cannot use method outbound transfer of object beyond the using block

43. //Our Code Here;

44. }

46. Improves access time

49. {

50. SPListItemCollection oListItems;

51. oListItems = (SPListItemCollection)Cache["ListItemCacheName"];

52. if(oListItems == null)

53. {

54. oListItems = DoQueryToReturnItems();

55. Cache.Add("ListItemCacheName", oListItems, ..);

56. }

57. }

59. {

60. DataTable oDataTable;

61. SPListItemCollection oListItems;

62. lock(this)

63. {

64. oDataTable = (DataTable)Cache["ListItemCacheName"];

65. if(oDataTable == null)

66. {

67. oListItems = DoQueryToReturnItems();

68. oDataTable = oListItems.GetDataTable();

69. Cache.Add("ListItemCacheName", oDataTable, ..);

70. }

71. }

73. Even with proper dispose, memory can grow

74. Projected concurrent users are a factor in your design

75. Size of farm employed to host

77. Is the data the same for all users or does it change? (Dependent on user account, department within the company, etc)

78. Is the data easily accessible or does it require a long time to return the data?

80. What is the size of the data?

81. Is the SharePoint site on a single server or on a server farm?

83. Memory Pressure in MOSS: http://blogs.technet.com/stefan_gossner/archive/2007/11/26/dealing-with-memory-pressure-problems-in-moss-wss.aspx

84. Memory leak checking tool : http://blogs.msdn.com/b/rogerla/archive/2009/01/29/automate-sharepoint-dispose-code-reviews-with-spdisposecheck.aspx

85. Memory Explained; The restaurant analogy: http://blogs.msdn.com/b/tess/archive/2006/09/06/net-memory-usage-a-restaurant-analogy.aspx