nix/host-modules/otel.nix

@@ -349,57 +349,6 @@ in
         settings = {
           receivers = {
             otlp.protocols.http.endpoint = listen;
-
-            # The host itself, which nothing else measures. hive-c0re emits
-            # per-container metrics and each service exports its own, so the
-            # store could answer "is this container using more memory than
-            # last week" and could not answer "is the machine under them out
-            # of memory" — the question every one of those readings is
-            # implicitly relative to.
-            #
-            # Here rather than in ./swarm-otel.nix because a host is owned by
-            # the hive running on it: the swarm tier runs one collector for
-            # the whole swarm and would have to reach *other* machines to see
-            # theirs. Consequence worth knowing before reading a dashboard:
-            # these samples carry `hive` and no `agent`, so "which host" is
-            # answered by "which hive" — true only while a hive is one host.
-            #
-            # Every scraper the pinned receiver offers except `process`, and
-            # the exception is not squeamishness about volume: `process` adds
-            # a series set PER RUNNING PROCESS, which on a hive host means
-            # every agent's claude and every nix build. That is unbounded and
-            # churning, where the nine below are a fixed handful per host
-            # forever. Coverage and cardinality are different axes and only
-            # the second one can hurt the store.
-            #
-            # Names verified against THIS collector version rather than
-            # upstream's docs, with a deliberately bogus scraper rejected in
-            # the same run so that "accepted" is distinguishable from "the
-            # validator ignores unknown keys". `validateConfigFile` above
-            # keeps that honest at build time.
-            hostmetrics = {
-              # Stated rather than inherited: the upstream default is a
-              # value that can change under a version bump, and the sample
-              # interval is the one knob here with a storage bill attached.
-              collection_interval = "60s";
-              scrapers = {
-                cpu = { };
-                memory = { };
-                filesystem = { };
-                load = { };
-                disk = { };
-                network = { };
-                paging = { };
-                # ⚠️ `processes` is the SUMMARY -- how many are running,
-                # blocked, sleeping. A handful of series per host. Its
-                # singular sibling `process` is the per-process one and is
-                # deliberately absent above; the two differ by one letter and
-                # a grep for the shorter name matches both, so read the
-                # trailing `s` before concluding which is configured here.
-                processes = { };
-                system = { };
-              };
-            };
           }
           # Only when a service has actually declared a target. An enabled
           # `prometheus` receiver with an empty `scrape_configs` renders,
@@ -458,15 +407,7 @@ in
             # `optional` matters too: a pipeline naming a receiver that no
             # longer exists is a startup failure, which `validateConfigFile`
             # below turns into a build failure rather than a broken deploy.
-            # `hostmetrics` is unconditional, unlike `prometheus` above: it
+            receivers = [ "otlp" ] ++ lib.optional (otel.scrapeTargets != { }) "prometheus";
-            # has no per-hive configuration to be empty of, so there is no
-            # inert shape to guard against — the receiver either collects the
-            # host's metrics or the host has none collected at all.
-            receivers = [
-              "otlp"
-              "hostmetrics"
-            ]
-            ++ lib.optional (otel.scrapeTargets != { }) "prometheus";
             exporters = [ swarmName ];
           };
         }