Recent seastar update included RPC metrics (scylladb/seastar#1753). The
reported metrics groups together sockets based on their "metrics_domain"
configuration option. This patch makes use of this domain to make scylla
metrics sane.
The domain as this patch defines it includes two strings:
First, the datacenter the server lives in. This is because grouping
metrics for connections to different datacenters makes little sense for
several reasons. For example -- packet delays _will_ differ for local-DC
vs cross-DC traffic and mixing those latencies together is pointless.
Another example -- the amount of traffic may also differ for local- vs
cross-DC connections e.g. because of different usage of enryption and/or
compression.
Second, each verb-idx gets its own domain. That's to be able to analyze
e.g. query-related traffic from gossiper one. For that the existing
isolation cookie is taken as is.
Note, that the metrics is _not_ per-server node. So e.g. two gossiper
connections to two different nodes (in one DC) will belong to the same
domain and thus their stats will be summed when reported.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#15785
492b842929