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Currently, Grouper sends messages (via AMQP or Amazon SNS) regarding changes going on in grouper Grouper with create/read/update/delete messages pertaining to groups, privileges, memberships, attribute changes, and possibly other activities. With respect to memberships in particular, the change and resulting message is incremental and includes essential information about the change along with the subject, the group and the action - usually ADD/DELETE. While there appears to be general agreement Identity Management related messages need to be delivered in order and never deleted (a deleted message implies not delivering in order), it remains possible actions represented by messages "get lost" either by the message broker system or by the consumer/processor itself on the receiving end of Grouper messages, OR an application fails in some way and needs to be synchronized with data/groups from Grouper.
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