Events are deferred if they are generated at a point in time when the logically available proxy server is physically not available, perhaps shut down for maintenance. These deferred events will be sent the next time any action occurs which requires communication with the proxy tool and when the server is physically available.

There are a few events which may not be delivered at the same time as the event occurs. Currently this only applies to a few events. Each applicable event will be noted in the documentation for that event. The following situations result in the deferred delivery of an event:

1. Restoring/importing a course which uses a proxy tool that is not installed.
2. Restoring/importing a course which uses a proxy tool that is installed but not available.
3. Restoring/importing a course which uses a proxy tool that is installed and available but not responding to requests.
4. Copying a course which uses a proxy tool that is installed but not available.
5. Copying a course which uses a proxy tool that is installed and available but not responding to requests.
6. Copying a content item (without delete) whose content handler is a proxy tool that is installed but not available.
7. Copying a content item (without delete) whose content handler is a proxy tool that is installed and available but not responding to requests.
8. Copying a content item (with delete, to a different course) whose content handler is a proxy tool that is installed but not available.
9. Copying a content item (with delete, to a different course) whose content handler is a proxy tool that is installed and available but not responding to requests.

The deferred events are sent to the proxy tool when it is installed (if required) and made available. As part of this action, any deferred events are sent to the proxy tool.

There is a chance that you may receive deferred events multiple times; the proxy tool must be able to deal with this. The scenario that would produce this is as follows: T0: Your server is down T1: Events A, B, C are deferred T2: Your server is brought up again T3: The administrator saves the tool to activate sending the deferred events T4: After sending event A successfully, your server goes down again. At this point we will stop attempting to send the deferred events, but later on when we try to send them we will start with event A again.

If the proxy tool uses tool settings then the deferred event will record the tool settings appropriate for the event at the time it was originally attempted to be sent. When it is eventually sent those original settings will be used regardless of the current settings at the time of the actual send.