Merger puts tasks 'In-Progress' for each task type that exists parallely (MAPCO-4446) #159

If exists, TilesMerger pulls a task for each task type, if tasks exist then all but one are "lost" and get a status of In-Progress.

The relevant code is in the MainRunner file:

phenomenon:
Once three ingestion processes are in parallel, tasks from all ingestion processes are moved to status In-Progress, although the merger does not work on them.

To Reproduce
Run multiple (at least 2) ingestion jobs with different ingestion types with existing tasks. (swap, new, update).

Actual behavior
Merger moves tasks to In-Progress although not working on them.

Expected behavior
Merger will "mark" only one task as In-Progress and work on it.