diff --git a/internal-dns-cli/src/bin/dnswait.rs b/internal-dns-cli/src/bin/dnswait.rs
index deddc699b2..f9875e71a0 100644
--- a/internal-dns-cli/src/bin/dnswait.rs
+++ b/internal-dns-cli/src/bin/dnswait.rs
@@ -36,8 +36,6 @@ struct Opt {
 #[value(rename_all = "kebab-case")]
 enum ServiceName {
     Cockroach,
-    // TODO: Remove clickhouse?
-    Clickhouse,
     ClickhouseKeeper,
     ClickhouseServer,
 }
@@ -46,7 +44,6 @@ impl From<ServiceName> for internal_dns::ServiceName {
     fn from(value: ServiceName) -> Self {
         match value {
             ServiceName::Cockroach => internal_dns::ServiceName::Cockroach,
-            ServiceName::Clickhouse => internal_dns::ServiceName::Clickhouse,
             ServiceName::ClickhouseServer => {
                 internal_dns::ServiceName::ClickhouseServer
             }
diff --git a/nexus/test-utils/src/lib.rs b/nexus/test-utils/src/lib.rs
index 453229bb36..914603dcee 100644
--- a/nexus/test-utils/src/lib.rs
+++ b/nexus/test-utils/src/lib.rs
@@ -1437,7 +1437,6 @@ pub async fn start_oximeter(
     let args = oximeter_collector::OximeterArguments {
         id,
         address: SocketAddrV6::new(Ipv6Addr::LOCALHOST, 0, 0, 0),
-        // TODO: Should this be configurable?
         replicated: false,
     };
     Oximeter::with_logger(&config, &args, log).await.map_err(|e| e.to_string())
diff --git a/oximeter/collector/src/agent.rs b/oximeter/collector/src/agent.rs
index 9264c2e1cf..ef1f58878b 100644
--- a/oximeter/collector/src/agent.rs
+++ b/oximeter/collector/src/agent.rs
@@ -429,10 +429,9 @@ impl OximeterAgent {
                 ..
             }) => {
                 debug!(log, "oximeter database does not exist, creating");
-                let is_oximeter_cluster = client.is_oximeter_cluster().await?;
                 client
                     .initialize_db_with_version(
-                        is_oximeter_cluster,
+                        replicated,
                         oximeter_db::OXIMETER_VERSION,
                     )
                     .await?;
diff --git a/oximeter/collector/src/bin/oximeter.rs b/oximeter/collector/src/bin/oximeter.rs
index 3f80533441..bdb1a35339 100644
--- a/oximeter/collector/src/bin/oximeter.rs
+++ b/oximeter/collector/src/bin/oximeter.rs
@@ -50,8 +50,8 @@ enum Args {
         #[clap(short, long, action)]
         address: SocketAddrV6,
 
-        // TODO: This flag should be removed once single node functionality
-        // is removed.
+        // TODO (https://github.com/oxidecomputer/omicron/issues/4148): This flag
+        // should be removed once single node functionality is removed.
         /// Is `oximeter` connecting to a replicated ClickHouse cluster
         #[clap(short, long, num_args = 0, action)]
         replicated: bool,
@@ -106,8 +106,8 @@ enum Args {
         #[arg(long, default_value_t = Level::Info, value_parser = parse_log_level)]
         log_level: Level,
 
-        // TODO: This flag should be removed once single node functionality
-        // is removed.
+        // TODO (https://github.com/oxidecomputer/omicron/issues/4148): This flag
+        // should be removed once single node functionality is removed.
         /// Is `oximeter` connecting to a replicated ClickHouse cluster
         #[clap(short, long, num_args = 0, action)]
         replicated: bool,
diff --git a/oximeter/collector/src/lib.rs b/oximeter/collector/src/lib.rs
index 9939408d22..68a92ebea0 100644
--- a/oximeter/collector/src/lib.rs
+++ b/oximeter/collector/src/lib.rs
@@ -146,7 +146,8 @@ impl Config {
 pub struct OximeterArguments {
     pub id: Uuid,
     pub address: SocketAddrV6,
-    // TODO: Remove once single node ClickHouse functionality is removed
+    // TODO TODO (https://github.com/oxidecomputer/omicron/issues/4148): Remove
+    // once single node ClickHouse functionality is removed
     pub replicated: bool,
 }
 
diff --git a/package/src/lib.rs b/package/src/lib.rs
index 47996dc781..87e300b4fb 100644
--- a/package/src/lib.rs
+++ b/package/src/lib.rs
@@ -75,6 +75,8 @@ pub enum TargetCommand {
             default_value = Some("single-node"),
             required = false
         )]
+        // TODO (https://github.com/oxidecomputer/omicron/issues/4148): Remove
+        // once single-node functionality is removed.
         /// Specify whether clickhouse will be deployed as a replicated cluster
         /// or single-node configuration.
         ///