Concurrency issues

The Malawi production instance has started seeing a bunch of issues that are related to concurrent requests (usually from the same user). The goal of this page is to keep track of the reported issues, pending discussions and possible fixes.

Possible causes of concurrent requests from the same user:

operations taking a long time and therefore making the user refresh the page and send a new request
offline mode breaking the loading modal and therefore allowing user to send a new request (https://openlmis.atlassian.net/browse/OLMIS-3163)
possibly missing loading modal in some states (like https://openlmis.atlassian.net/browse/MALAWISUP-133)
is it somehow possible to double click on an action button before loading modal is displayed? (perhaps on slower computers?) Less technical users may be double-clicking on buttons and links

Other causes of concurrent requests:

concurrent requests are to be expected - users may have access to the same resources and they can invoke actions on them in the same time

Current issues caused by concurrent reqeuests:

duplicate comments / status messages - https://openlmis.atlassian.net/browse/MW-203
duplicate requisition initiate, displaying weird errors to the user (a workaround has been applied in Malawi) - https://openlmis.atlassian.net/browse/MW-586
duplicate adjustments reasons (difficult to reproduce, but happens once in a while) - https://openlmis.atlassian.net/browse/MALAWISUP-86
https://openlmis.atlassian.net/browse/MALAWISUP-181 originally caused by duplicate adjustment reasons (https://openlmis.atlassian.net/browse/MALAWISUP-86)
most likely more...

Pending discussion:

https://groups.google.com/forum/#!topic/openlmis-dev/C3PtdbK0m5I