Error Message

One of two errors will be seen in a client trace set to max tracing.

Scenario 1:

HDR:SYNC:ARC: MDC::Sync::FullSyncHandleFromEVItems: Creating stub. SNUM: 225411
HDR:PST: MDC::PSTCacheFolder::CreateMessage: 0x0
HDR:PST: MDC::PSTCacheFolder::SetModifiedBySync
HDR:PST: ~MDC::PSTCacheFolder::SetModifiedBySync
HDR:MSG: MDC::PSTCacheMessage::PSTCacheMessage: 0x0
HDR:MSG: MDC::PSTCacheMessage::AddRecipients: 0x0
HDR:MSG: ~MDC::PSTCacheMessage::AddRecipients: 0x0
HDR:MSG: ~MDC::PSTCacheMessage::PSTCacheMessage: 0x80040119
HDR:PST: ~MDC::PSTCacheFolder::CreateMessage: 0x0
HDR:PST: MDC::PSTCacheSearchFolder::~PSTCacheSearchFolder
………
HDR:SYNC:ARC: Sync Report - Aborted before fully complete
HDR:SYNC:ARC: Sync Report - FromSrv: New folders found: 207
HDR:SYNC:ARC: Sync Report - FromSrv: MDC items created: 766566
HDR:SYNC:ARC: ~MDC::MDCSyncReport::TraceSyncReport

Scenario 2:

 HDR:SYNC:ARC: Notifying the Content Cache about messages that were created in the archive and about those that were deleted
HDR:PST: MDC::PSTCacheTree::SetCacheState
HDR:PST: CacheState set to: 6
[snip]
HDR:PST: MDC::PSTCacheFolderIteratorBase::PSTCacheFolderIteratorBase: 0x0
HDR:PST: MDC::PSTCacheFolderIteratorBase::GetTable: 0x0
HDR:PST: ~MDC::PSTCacheFolderIteratorBase::GetTable: 0x0
HDR:PST: MDC::PSTCacheFolderIteratorBase::GetNextValue: 0x0
HDR:PST: ~MDC::PSTCacheFolderIteratorBase::GetNextValue: 0x800408CA
HDR:PST: ~MDC::PSTCacheFolderIteratorBase::PSTCacheFolderIteratorBase: 0x0

According to Microsoft this issue may occur for users with more than 100,000 items in a single folder. Microsoft guidelines around the number of items in a single folder are discussed in the following document: https://support.microsoft.com/en-gb/help/2768656/outlook-performance-issues-when-there-are-too-many-items-or-folders-in-a-cached-mode-.ost-or-.pst-file-folder

Per Microsoft there are hard limits in the storage structures they use inside PST files. The MDC file is based on PST technologies. In this particular scenario the data being created inside the MDC file is hitting one of the limits mentioned by Microsoft. Once that limit is reached, no further data can be added to the folder and behavior is undefined.

Note: Our testing has shown the exact number of items required in a folder depends on the data itself, and therefore will vary greatly.

Solution

Recommendations:

1. Use Enterprise Vault Search to find the items in the archive on the client machine.
2. Keep the number of items in a single folder smaller potentially less than 100k as per Microsoft article referenced above when importing data in to an Enterprise Vault archive.
3. Use IMAP instead of Virtual vault.

Metadata (also known as header) synchronization is a process where a metadata cache (MDC) file is built on the user’s client machine, inside of which stubs are created for each item that exists in the user’s Archive. ‘Stub’ refers to an item that represents an archived item with limited metadata attributes. This MDC file is used by Virtual Vault to present a user with a view of their Archive from within Outlook.

If a user has a very large archive containing many hundreds of thousands of items per folder, the initial MDC synchronization may fail, with an exception. As a result of this failure, Vault Cache header synchronization will not complete, and Virtual Vault will not be loaded into the user’s Outlook profile. The exact limit of items isn't known, as it depends on the internal structure of the .PST and the layout of the items and folders. It's possible that an existing MDC file may continue to synchronize past the limit, due to incremental synchs. If Vault Cache were to be reset, a full synch would then be needed, where the issue would then be seen.

Error Message

One of two errors will be seen in a client trace set to max tracing. Scenario 1: HDR:SYNC:ARC: MDC::Sync::FullSyncHandleFromEVItems: Creating stub. SNUM: 225411
HDR:PST: MDC::PSTCacheFolder::CreateMessage: 0x0
HDR:PST: MDC::PSTCacheFolder::SetModifiedBySync
HDR:PST: ~MDC::PSTCacheFolder::SetModifiedBySync
HDR:MSG: MDC::PSTCacheMessage::PSTCacheMessage: 0x0
HDR:MSG: MDC::PSTCacheMessage::AddRecipients: 0x0
HDR:MSG: ~MDC::PSTCacheMessage::AddRecipients: 0x0
HDR:MSG: ~MDC::PSTCacheMessage::PSTCacheMessage: 0x80040119
HDR:PST: ~MDC::PSTCacheFolder::CreateMessage: 0x0
HDR:PST: MDC::PSTCacheSearchFolder::~PSTCacheSearchFolder
………
HDR:SYNC:ARC: Sync Report - Aborted before fully complete
HDR:SYNC:ARC: Sync Report - FromSrv: New folders found: 207
HDR:SYNC:ARC: Sync Report - FromSrv: MDC items created: 766566
HDR:SYNC:ARC: ~MDC::MDCSyncReport::TraceSyncReport Scenario 2: HDR:SYNC:ARC: Notifying the Content Cache about messages that were created in the archive and about those that were deleted
HDR:PST: MDC::PSTCacheTree::SetCacheState
HDR:PST: CacheState set to: 6
[snip]
HDR:PST: MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::PSTCacheFolderIteratorBase: 0x0
HDR:PST: MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::GetTable: 0x0
HDR:PST: ~MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::GetTable: 0x0
HDR:PST: MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::GetNextValue: 0x0
HDR:PST: ~MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::GetNextValue: 0x800408CA
HDR:PST: ~MDC::PSTCacheFolderIteratorBase<class MDC::PSTCacheFolder,class MDC::PSTCacheMessage>::PSTCacheFolderIteratorBase: 0x0

ETrack: 3814985