Metrics Correlated to "Health" of Bitcoin Node and Network

[Bitcoin]

Metrics Correlated to "Health" of Bitcoin Node and Network

What metrics can I use as indicators of the health of (a) a full bitcoin node I am running and (b) the bitcoin network as a whole.

Some examples I've considered: recency of last block I received on my node is a good indicator of (a) or (b) -- if a long time passes, I have an indication that either my node or the network is not in a good state.  The number of full nodes (N) participating in the network is a good measure of (b).  N is difficult to measure but the folks here are taking a good run at it: https://getaddr.bitnodes.io/

What other metrics should I look at on my nodes or on broader level across the network, to gauge the health of my nodes and the network?

Source: Metrics Correlated to "Health" of Bitcoin Node and Network