The problem I have is - we need to process & change(update/insert) 55M Data every 2 min and this updated data to be available for Rest API for Filtering / Selection. Response time for Rest API should be less than 1 sec.
The most important factors for me are processing and storing time of 2 min. There need to be 2 views of Data One is for Selection & 2. Changed data.
Why an issue? Is AGPL a problem for you? It only means that if you change the source code of the server you need to contribute your scylla.git changes. 99.99999% of users don't need to change a single line thus it's the same as Apache.
Licensing policy suggests `We promise that we will not seek to enforce the copyleft provisions in the AGPL v3.0`, sadly license overrules promise. AGPL as a license is not that widely used or preferred, and there are very good reasons for it.
Most companies are already doing good with Cassandra, and to jump into a new database project with a complex license the incentive, just isnt there. no matter how good the benchmarks are.
Cassandra is quite capable of the task, in a highly available way, given appropriate scaling of the system. Remember that updates are only inserts, and that efficient retrieval is only by key (which can be a complex key). Talking of keys, make sure that the keys are well distributed.