Feature request: KAS processing threshold provided by AccountLimit

[stophane]

Starting with KIM 1.5 specification, the current threshold from which a KIM-Clientmodul processes received/large mail data by the defined 'KAS process' is fixed to 15 MiB. Any KIM mail smaller than 15 MiB must be processed 'normally'/fully by TI-Konnektor.

To mitigate the known performance & memory issues of the TI-Konnektor, it might be benefitial to allow a smaller, by all means, variable threshold from which the KIM-Clientmodul uses the 'KAS process' instead of processing large amounts of data by a TI-Konnektor.

Solution:
Extend AccountLimit by a property 'kasMailSizeThreshold', which allows a threshold between 1 MiB and 15 MiB (default). Currently any KIM-Clientmodul implementing KIM 1.5 specification must request the AccountLimit before sending a message.

Advantage:

• This might increase the overall performance, e.g. by reducing the time required to send or receive KIM messages.
• As the AccountLimit already implies account-wise information, a KIM provider is enabled to set a threshold account-wise or globally for any account.

Disadvantage:

• A low threshold might result in more data stored on the KAS. This data isn´t explicitly managed by client´s or client software. Thus the on the KAS stored data is primarly managed through deletion by expiration (dataTimeToLive).

The KIM/KAS provider must decide/manage the threshold value, as the overall KAS performance and related storage management might be individual to each provider.

[dhufnagel]

Any explanation why this PR was closed without merging?

[gem-uku]

merge is done directly to develop branche

[dhufnagel]

I would appreciate doing a proper merge of the Pull requests next time, as it would honor the work of the people doing the actual work by mentioning them in the contributors list. A "manual merge" is not a good solution - imho.