Hello, I have a cluster with dedicated master nodes. I recently noticed, that the current master has relatively high network bandwidth requirements (sustained non-stop ~15Mb/s in, and ~15Mb/s out). It seems that the traffic between the master node and the individual data nodes is proportional to the number of indices/segments on the respective data node. Is there any info/guide regarding the network requirements of master-only nodes and how to optimize it?
Also, as a bonus, I noticed a long-term pattern, where the traffic goes rapidly down (around 50%) every 3-4 days and then slowly climbs back up to the ~15Mb/s over the course of 24 hours, stays there for ~3 days and falls back to 50% as the next "iteration" starts. Any idea what could be the reason? The number of indices is only growing, we do not delete large amounts of data with that period.