Update Oximeter-related DataStore methods for incoming reconfigurator…

… support (#6518)

This PR adds two new `DataStore` methods:

* `oximeter_delete` (soft deletes an oximeter instance, which also
requires a small migration to add a `time_deleted` column)
* `oximeter_reassign_all_producers` (reassigns all metric producers from
one oximeter instance to random other instances)

and updates existing methods to account for the possibility that an
oximeter instance may have been deleted (e.g., don't return deleted
instances when listing).

There are no callers of these methods in this PR, but there will be in
the upcoming reconfigurator-can-rebalance-oximeter PR.

nexus/db-model/src/oximeter_info.rs

@@ -9,7 +9,7 @@ use nexus_types::internal_api;
 use uuid::Uuid;
 
 /// A record representing a registered `oximeter` collector.
-#[derive(Queryable, Insertable, Debug, Clone, Copy)]
+#[derive(Queryable, Insertable, Debug, Clone, Copy, PartialEq, Eq)]
 #[diesel(table_name = oximeter)]
 pub struct OximeterInfo {
     /// The ID for this oximeter instance.
@@ -18,6 +18,17 @@ pub struct OximeterInfo {
     pub time_created: DateTime<Utc>,
     /// When this resource was last modified.
     pub time_modified: DateTime<Utc>,
+    /// When this resource was expunged.
+    //
+    // We typically refer to _zones_ as expunged; this isn't quite the same
+    // thing since this is the record of a running Oximeter instance. Some time
+    // after an Oximeter zone has been expunged (usually not very long!), the
+    // blueprint_executor RPW will mark the Oximeter instance that was running
+    // in that zone as expunged, setting this field to a non-None value, which
+    // will cause it to no longer be chosen as a potential collector for
+    // producers (and will result in any producers it had been assigned being
+    // reassigned to some other collector).
+    pub time_expunged: Option<DateTime<Utc>>,
     /// The address on which this `oximeter` instance listens for requests.
     pub ip: ipnetwork::IpNetwork,
     /// The port on which this `oximeter` instance listens for requests.
@@ -31,6 +42,7 @@ impl OximeterInfo {
             id: info.collector_id,
             time_created: now,
             time_modified: now,
+            time_expunged: None,
             ip: info.address.ip().into(),
             port: info.address.port().into(),
         }

nexus/db-model/src/schema.rs

@@ -794,6 +794,7 @@ table! {
         id -> Uuid,
         time_created -> Timestamptz,
         time_modified -> Timestamptz,
+        time_expunged -> Nullable<Timestamptz>,
         ip -> Inet,
         port -> Int4,
     }

nexus/db-model/src/schema_versions.rs

@@ -17,7 +17,7 @@ use std::collections::BTreeMap;
 ///
 /// This must be updated when you change the database schema.  Refer to
 /// schema/crdb/README.adoc in the root of this repository for details.
-pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(97, 0, 0);
+pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(98, 0, 0);
 
 /// List of all past database schema versions, in *reverse* order
 ///
@@ -29,6 +29,7 @@ static KNOWN_VERSIONS: Lazy<Vec<KnownVersion>> = Lazy::new(|| {
         // |  leaving the first copy as an example for the next person.
         // v
         // KnownVersion::new(next_int, "unique-dirname-with-the-sql-files"),
+        KnownVersion::new(98, "oximeter-add-time-expunged"),
         KnownVersion::new(97, "lookup-region-snapshot-by-region-id"),
         KnownVersion::new(96, "inv-dataset"),
         KnownVersion::new(95, "turn-boot-on-fault-into-auto-restart"),

nexus/db-queries/src/db/datastore/mod.rs

@@ -115,6 +115,7 @@ pub use dns::DnsVersionUpdateBuilder;
 pub use instance::{InstanceAndActiveVmm, InstanceGestalt};
 pub use inventory::DataStoreInventoryTest;
 use nexus_db_model::AllSchemaVersions;
+pub use oximeter::CollectorReassignment;
 pub use rack::RackInit;
 pub use rack::SledUnderlayAllocationResult;
 pub use region::RegionAllocationFor;