part #2

src/Concelier/StellaOps.Concelier.WebService/Program.cs

@@ -491,6 +491,9 @@ builder.Services.AddConcelierPostgresStorage(pgOptions =>
     pgOptions.MigrationsPath = postgresOptions.MigrationsPath;
 });
 
+// Register in-memory lease store (single-instance dev mode).
+builder.Services.AddSingleton<StellaOps.Concelier.Core.Jobs.ILeaseStore, StellaOps.Concelier.Core.Jobs.InMemoryLeaseStore>();
+
 builder.Services.AddOptions<AdvisoryObservationEventPublisherOptions>()
     .Bind(builder.Configuration.GetSection("advisoryObservationEvents"))
     .PostConfigure(options =>

src/Concelier/__Libraries/StellaOps.Concelier.Core/Jobs/InMemoryLeaseStore.cs

@@ -0,0 +1,65 @@
+namespace StellaOps.Concelier.Core.Jobs;
+
+/// <summary>
+/// In-memory lease store for single-instance deployments.
+/// For multi-instance deployments, replace with a Postgres-backed implementation.
+/// </summary>
+public sealed class InMemoryLeaseStore : ILeaseStore
+{
+    private readonly object _lock = new();
+    private readonly Dictionary<string, JobLease> _leases = new();
+
+    public Task<JobLease?> TryAcquireAsync(
+        string key,
+        string holder,
+        TimeSpan leaseDuration,
+        DateTimeOffset now,
+        CancellationToken cancellationToken)
+    {
+        lock (_lock)
+        {
+            if (_leases.TryGetValue(key, out var existing) && existing.TtlAt > now && existing.Holder != holder)
+            {
+                return Task.FromResult<JobLease?>(null);
+            }
+
+            var lease = new JobLease(key, holder, now, now, leaseDuration, now.Add(leaseDuration));
+            _leases[key] = lease;
+            return Task.FromResult<JobLease?>(lease);
+        }
+    }
+
+    public Task<JobLease?> HeartbeatAsync(
+        string key,
+        string holder,
+        TimeSpan leaseDuration,
+        DateTimeOffset now,
+        CancellationToken cancellationToken)
+    {
+        lock (_lock)
+        {
+            if (_leases.TryGetValue(key, out var existing) && existing.Holder == holder)
+            {
+                var lease = new JobLease(key, holder, existing.AcquiredAt, now, leaseDuration, now.Add(leaseDuration));
+                _leases[key] = lease;
+                return Task.FromResult<JobLease?>(lease);
+            }
+
+            return Task.FromResult<JobLease?>(null);
+        }
+    }
+
+    public Task<bool> ReleaseAsync(string key, string holder, CancellationToken cancellationToken)
+    {
+        lock (_lock)
+        {
+            if (_leases.TryGetValue(key, out var existing) && existing.Holder == holder)
+            {
+                _leases.Remove(key);
+                return Task.FromResult(true);
+            }
+        }
+
+        return Task.FromResult(false);
+    }
+}