com.atlassian.crowd.directory.cache

Class DeltaQueryCacheRefresher

java.lang.Object

com.atlassian.crowd.directory.cache.DeltaQueryCacheRefresher

All Implemented Interfaces:

CacheRefresher

public class DeltaQueryCacheRefresher
extends Object
implements CacheRefresher

Performs delta queries on Azure Active Directory to facilitate incremental synchronisation. More details can be found at https://developer.microsoft.com/en-us/graph/docs/concepts/delta_query_overview If no delta tokens are present a full synchronisation using Azure AD's delta endpoints will be performed to obtain delta tokens for future incremental syncs. As Azure AD returns a diff of group memberships, this cache refresher will add/remove the memberships specified by Azure AD instead of diffing current memberships with the ones obtained from the remote directory. This also causes a slight overhead due to the need to look up entity names for those memberships as Azure AD only specifies external ids and Crowd needs names. To facilitate this the names for added/changed entities are added into a cache local to a synchronisation and the cache is then populated whenever a lookup is performed. This CacheRefresher uses worker threads for synchronisation. There are two reasons for this:

• Increasing performance by concurrently fetching both users and groups
• Minimising the chance to have an outdated set of users and groups. As these are handled by two separate endpoints and use two separate tokens for tracking their state it's possible that one set will refer to outdated information. For example a user was added to a group and this information was fetched from the groups endpoint. However the user was deleted after that and the deletion was contained in the response from the users endpoint. Concurrent fetching reduces the window for such changes, however they are still possible.

Constructor Summary

Constructors

Constructor and Description
DeltaQueryCacheRefresher(AzureAdDirectory remoteDirectory)

Method Summary

Modifier and Type	Method and Description
CacheSynchronisationResult	synchroniseAll(DirectoryCache directoryCache) Will visit all Users and Groups in the external directory in order to do a Full refresh.
CacheSynchronisationResult	synchroniseChanges(DirectoryCache directoryCache, String syncToken) Attempts to synchronise changes since the last refresh as opposed to performing a full synchronisation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DeltaQueryCacheRefresher

public DeltaQueryCacheRefresher(AzureAdDirectory remoteDirectory)

Method Detail

synchroniseAll

public CacheSynchronisationResult synchroniseAll(DirectoryCache directoryCache)
                                          throws OperationFailedException

Description copied from interface: CacheRefresher

Will visit all Users and Groups in the external directory in order to do a Full refresh.

Specified by:

synchroniseAll in interface CacheRefresher

Parameters:

directoryCache - the DirectoryCache to update.

Returns:

result of synchronisation

Throws:

OperationFailedException - if there was an error processing the operation

synchroniseChanges

public CacheSynchronisationResult synchroniseChanges(DirectoryCache directoryCache,
                                                     @Nullable
                                                     String syncToken)
                                              throws OperationFailedException

Description copied from interface: CacheRefresher

Attempts to synchronise changes since the last refresh as opposed to performing a full synchronisation. Returns true if changes since the last refresh were synchronised successfully.

Specified by:

synchroniseChanges in interface CacheRefresher

Parameters:

directoryCache - the DirectoryCache to update.

Returns:

result of the synchronisation

Throws:

OperationFailedException - if there was an error processing the operation