Document information about the current solution

Signed-off-by: Akashdeep Dhar <akashdeep.dhar@gmail.com>

docs/fcas/creation_fail.rst

@@ -0,0 +1,61 @@
+.. _creation_fail:
+
+Why does the existing solution not work?
+====
+
+The existing solution does not work anymore and necessitates the need of a new
+solution because of the following reasons.
+
+Internal reasons
+----
+
+The existing solution does not work anymore because of the following reasons 
+pertaining to the system itself.
+
+1. Retrieval of a filtered list of human-only usernames from FASJSON service is
+   a performance intensive process and time consuming process both at the 
+   serving and the receiving end. Having the service unit to fetch the list of
+   all usernames not only delivers penalty to the performance of the service 
+   unit itself but also harms the experience of those using FASJSON service at
+   their ends. This can lead to severely unintended consequences such as 
+   causing an unplanned downtime at the serving end, hogging up the reources 
+   due to the contigious nature of the request and deteriorating the quality of
+   service for other FASJSON users.
+
+2. Obtaining a moderated list of active human-only usernames from Datagrepper
+   is also a performance intensive and time consuming process both at the 
+   serving and the receiving end. While running this service unit does not 
+   deteriorate the quality of service of Datagrepper for other users, the 
+   process is very slow as the Datagrepper service has to further interact with
+   the Datanommer database in order to be able to compute the request and fetch
+   the requested information elements. As a consequence, the service unit 
+   runtime is very long and can be incredibly dependent on the network 
+   performance of the client machine.
+
+3. Having too many entities in the system not only makes it complicated but it
+   also brings in the added risks of failure and cost in time and effort 
+   required to connect these entities with each other in the form of processes.
+   For instance, the service unit for fetching all the usernames from FASJSON 
+   takes more than 90-120 minutes in one run and that for fetching all the
+   active usernames from Datagrepper takes more than 330-360 minutes in one 
+   run. This severely restricts the opportunities for development of new 
+   features and quality-of-life updates as the testing workflow could end up 
+   easily taking a lot of time and resources.
+
+External reasons
+----
+
+An new and improved solution is made necessary because of the following reasons
+pertaining to the external entities.
+
+1. In the wake of increased requirements from the stakeholders, the scope of
+   the tool widened drastically to a point that the existing solution could not
+   be extended to address the newer needs. While the design ideas and the 
+   processes could be followed from the existing solution, the improved 
+   solution was required to be developed to ensure it could handle larger data
+   elements, compute them to find out statistics about human-only users, amount
+   for multiple services that publish messages on the Fedora Messaging bus and
+   generate contribution statistics effectively. Therefore, an initiative was 
+   proposed to better facilitate these needs.
+
+

docs/fcas/index.rst

@@ -97,5 +97,6 @@ Index
 
     creation_workflow
     creation_gram
+    creation_fail
     solution_workflow
     proposed_technologies