Hi,
I followed to icinga from version 1.x to 2.x, tried from IDOdb, livestatus to icingadb. Currently, with the new design, we have new database in sql and redis server in the middle. I see that the information in redis is almost the same information in sql
In my opinion, it will be better if we design the redis server as a graph, and redis also supports graph database redis graph. Because redis is not support join, filter information in the current design is not native, for example, filter regex in service name and host name in the same query. We can also think about split database into 2 databases: one for graph database (which stands for currents object information such as state, check output, etc.) and one for historical data (sql, mongo, etc.). I suggest that for the graph database we can use redis graph or arangodb (which is free and have free clusters to scale instead of neo4j) to store current icinga object which will help us much more powerful and performance when we need to query current data. Redis will be a cache to speed up. Hope that the filter for current data can be light-weight, fast and powerful as LQL of livestatus.