More on Inconsistencies

Are inconsistencies acceptable? #

As per the last lesson, the inconsistency of an asynchronous system is inevitable unless you want to give up availability.

It is therefore important to know the requirements for consistency, which requires some skill. Customers want a reliable system, data inconsistency seems to contradict this. That’s why it is important to know what happens when the data is temporarily inconsistent and whether this really causes problems.

After all, the inconsistencies should usually disappear after a few seconds. Besides, certain inconsistencies can even be tolerable from a domain perspective.

• For example, if goods are listed days before the first sale, inconsistencies are initially acceptable and must only be corrected when the goods are finally being sold.

If inconsistencies are not acceptable at all, asynchronous communication is not an option.

This means that synchronous communication must be used with all its disadvantages. If the tolerance for temporarily inconsistent data is not known, this can lead to a wrong decision regarding the communication variant.