Archive Shuttle Office 365 Module may log Exchange service is busy error (4294234)

Overview

The Archive Shuttle Office 365 module may log the following error:

2015-02-05 08:46:57Z|3456| 36|ERROR|CallService|[user1@test.com]: Error during call to Exchange Service - ServiceResponse: [Internal Server Error][InternalServerError].
2015-02-05 08:46:57Z|3456| 52| WARN|SetBackoffEnd|Exchange/Office365 EWS Server Busy - will continue ingest after: [2015-02-05 08:51:57Z] 
2015-02-05 08:46:57Z|3456| 52| INFO|CallService|[user1@test.com]: Exchange service is busy. Sleeping thread for [30000 ms]

Solution

Office 365 module gets such message from Exchange Web Service and it means that ingest of items is postponed for some amount of time.
In order to avoid this error:

• ask Microsoft to relax throttling limit, or
• add more accounts with Impersonation Permissions, or
• change Office 365 module threads, e.g go down with item parallelism as 1 per mailbox. With higher mailbox parallelism, it is necessary to adjust EV Export Module settings as well, so the export provides enough work for the import across a higher number of containers (e.g. try 20/4 instead of 5/15).