Requirements MODORDERS-106 - Getting issue details... STATUS
The last step in receiving/check-in flow is to update the status of PO Line to "Partially Received" or "Fully Received". It's possible that something may go wrong and status won't be updated even though the items were actually received.
So the mechanism to guarantee the status is up-to-date needs to be worked out.
Investigation
From the technical side this means that there may be a discrepancy between the status of the PO line and the statuses of its associated pieces in the database. The following connections are possible between PO line with PARTIALLY_RECEIVED and FULLY_RECEIVED statuses and state of pieces:
- there are pieces related to PO line that are in the RECEIVED and EXPECTED statuses - the PO line must be in the PARTIALLY_RECEIVED status;
- all pieces are in RECEIVED status - the PO line must be in FULLY_RECEIVED status.
Thus, the task is to create a mechanism that would allow changing the status of the PO line when the status of its associated pieces changes.
Two types of approaches can be offered - "scheduled-style" mechanism that check the status of pieces and change the status of the PO line if necessary; “injection-style” mechanism that monitor changes in the status of pieces and change the status of the PO line if necessary.
Scheduled-style mechanism
This group of approaches is based on periodic scanning of all saved pieces and determining the status of poline on this basis. A typical algorithm for such mechanism might look as shown on Figure 1.
Figure 1 - A general algorithm of mechanisms based on periodic scanning of the entire set of pieces.
Particular implementations of this approach are presented below.
Vert.X Periodic Timer
Within the Vert.X features #_executing_periodic_and_delayed_actions one can implement a mechanism that periodically retries the pieces and checks the status of the poline, changing it if necessary. There is a need to develop a mechanism that monitors pieces status in cluster mode, when each mod-orders / mod-orders-storage instance will start the scheduler entity. Thus, it is necessary to provide a solution so that the instances of the scheduler from each mod-orders / mod-orders-storage do not compete and do extra pieces checking.
Separate Scheduler Application
PostgreSQL cron-job
Interceptor-style mechanisms
This group of mechanisms is based on the injection of logic into the process, which checks the status of poline and its associated pieces. This logic checks the consistency of statuses and provides poline status changes, if necessary. The algorithm looks as shown on Figure 2.
Figure 2 - A general algorithm of mechanisms based on consistency checking as part of retrieving flow.
Checking and updating the PO line status upon retrieving
PostgreSQL Trigger Functions