Timer workers (part 1) (#1863)

Co-authored-by: stas <statis@microsoft.com>

src/ApiService/ApiService/Log.cs

@@ -8,7 +8,7 @@ namespace Microsoft.OneFuzz.Service;
 public interface ILog {
     void Log(Guid correlationId, String message, SeverityLevel level, IReadOnlyDictionary<string, string> tags, string? caller);
     void LogEvent(Guid correlationId, String evt, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller);
-    void LogException(Guid correlationId, Exception ex, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller);
+    void LogException(Guid correlationId, Exception ex, string message, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller);
     void Flush();
 }
 
@@ -37,7 +37,7 @@ class AppInsights : ILog {
 
         _telemetryClient.TrackEvent(evt, properties: copyTags, metrics: copyMetrics);
     }
-    public void LogException(Guid correlationId, Exception ex, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller) {
+    public void LogException(Guid correlationId, Exception ex, string message, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller) {
         Dictionary<string, string> copyTags = new(tags);
         copyTags["Correlation ID"] = correlationId.ToString();
         if (caller is not null) copyTags["CalledBy"] = caller;
@@ -47,6 +47,8 @@ class AppInsights : ILog {
             copyMetrics = new(metrics);
         }
         _telemetryClient.TrackException(ex, copyTags, copyMetrics);
+
+        Log(correlationId, $"{message} : {ex.Message}", SeverityLevel.Error, tags, caller);
     }
 
     public void Flush() {
@@ -89,8 +91,8 @@ class Console : ILog {
         LogTags(correlationId, tags);
         LogMetrics(correlationId, metrics);
     }
-    public void LogException(Guid correlationId, Exception ex, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller) {
-        System.Console.Out.WriteLine($"[{correlationId}][Exception] {ex}");
+    public void LogException(Guid correlationId, Exception ex, string message, IReadOnlyDictionary<string, string> tags, IReadOnlyDictionary<string, double>? metrics, string? caller) {
+        System.Console.Out.WriteLine($"[{correlationId}][Exception] {message}:{ex}");
         LogTags(correlationId, tags);
         LogMetrics(correlationId, metrics);
     }
@@ -105,7 +107,7 @@ public interface ILogTracer {
     void Critical(string message);
     void Error(string message);
     void Event(string evt, IReadOnlyDictionary<string, double>? metrics);
-    void Exception(Exception ex, IReadOnlyDictionary<string, double>? metrics = null);
+    void Exception(Exception ex, string message = "", IReadOnlyDictionary<string, double>? metrics = null);
     void ForceFlush();
     void Info(string message);
     void Warning(string message);
@@ -238,10 +240,10 @@ public class LogTracer : ILogTracerInternal {
         }
     }
 
-    public void Exception(Exception ex, IReadOnlyDictionary<string, double>? metrics) {
+    public void Exception(Exception ex, string message, IReadOnlyDictionary<string, double>? metrics) {
         var caller = GetCaller();
         foreach (var logger in _loggers) {
-            logger.LogException(CorrelationId, ex, Tags, metrics, caller);
+            logger.LogException(CorrelationId, ex, message, Tags, metrics, caller);
         }
     }
 

src/ApiService/ApiService/OneFuzzTypes/Enums.cs

@@ -121,9 +121,9 @@ public enum JobState {
 }
 
 public static class JobStateHelper {
-    private static readonly HashSet<JobState> _shuttingDown = new HashSet<JobState>(new[] { JobState.Stopping, JobState.Stopped });
-    private static readonly HashSet<JobState> _avaiable = new HashSet<JobState>(new[] { JobState.Init, JobState.Enabled });
-    private static readonly HashSet<JobState> _needsWork = new HashSet<JobState>(new[] { JobState.Init, JobState.Stopping });
+    private static readonly IReadOnlySet<JobState> _shuttingDown = new HashSet<JobState>(new[] { JobState.Stopping, JobState.Stopped });
+    private static readonly IReadOnlySet<JobState> _avaiable = new HashSet<JobState>(new[] { JobState.Init, JobState.Enabled });
+    private static readonly IReadOnlySet<JobState> _needsWork = new HashSet<JobState>(new[] { JobState.Init, JobState.Stopping });
 
     public static IReadOnlySet<JobState> Available => _avaiable;
     public static IReadOnlySet<JobState> NeedsWork => _needsWork;
@@ -354,3 +354,33 @@ public enum AgentMode {
     Repro,
     Proxy
 }
+
+
+public enum NodeState {
+    Init,
+    Free,
+    SettingUp,
+    Rebooting,
+    Ready,
+    Busy,
+    Done,
+    Shutdown,
+    Halt,
+}
+
+public static class NodeStateHelper {
+
+    private static readonly IReadOnlySet<NodeState> _needsWork = new HashSet<NodeState>(new[] { NodeState.Done, NodeState.Shutdown, NodeState.Halt });
+    private static readonly IReadOnlySet<NodeState> _readyForReset = new HashSet<NodeState>(new[] { NodeState.Done, NodeState.Shutdown, NodeState.Halt });
+    private static readonly IReadOnlySet<NodeState> _canProcessNewWork = new HashSet<NodeState>(new[] { NodeState.Free });
+
+
+    public static IReadOnlySet<NodeState> NeedsWork => _needsWork;
+
+    ///If Node is in one of these states, ignore updates from the agent.
+    public static IReadOnlySet<NodeState> ReadyForReset => _readyForReset;
+
+    public static IReadOnlySet<NodeState> CanProcessNewWork => _canProcessNewWork;
+}
+
+

src/ApiService/ApiService/OneFuzzTypes/Events.cs

@@ -60,6 +60,7 @@ public abstract record BaseEvent() {
                 EventScalesetFailed _ => EventType.ScalesetFailed,
                 EventScalesetResizeScheduled _ => EventType.ScalesetResizeScheduled,
                 EventScalesetStateUpdated _ => EventType.ScalesetStateUpdated,
+                EventNodeDeleted _ => EventType.NodeDeleted,
                 _ => throw new NotImplementedException(),
             };
 
@@ -81,7 +82,10 @@ public abstract record BaseEvent() {
             EventType.TaskFailed => typeof(EventTaskFailed),
             EventType.TaskStopped => typeof(EventTaskStopped),
             EventType.TaskStateUpdated => typeof(EventTaskStateUpdated),
-
+            EventType.ScalesetFailed => typeof(EventScalesetFailed),
+            EventType.ScalesetResizeScheduled => typeof(EventScalesetResizeScheduled),
+            EventType.ScalesetStateUpdated => typeof(EventScalesetStateUpdated),
+            EventType.NodeDeleted => typeof(EventNodeDeleted),
             _ => throw new ArgumentException($"invalid input {eventType}"),
 
         };
@@ -102,7 +106,7 @@ public record EventTaskStopped(
 ) : BaseEvent();
 
 
-record EventTaskFailed(
+public record EventTaskFailed(
     Guid JobId,
     Guid TaskId,
     Error Error,
@@ -118,14 +122,14 @@ record EventTaskFailed(
 //    ) : BaseEvent();
 
 
-record JobTaskStopped(
+public record JobTaskStopped(
     Guid TaskId,
     TaskType TaskType,
     Error? Error
     ) : BaseEvent();
 
 
-record EventJobStopped(
+public record EventJobStopped(
     Guid JobId,
     JobConfig Config,
     UserInfo? UserInfo,
@@ -141,7 +145,7 @@ record EventJobStopped(
 //    ) : BaseEvent();
 
 
-record EventTaskStateUpdated(
+public record EventTaskStateUpdated(
     Guid JobId,
     Guid TaskId,
     TaskState State,
@@ -245,11 +249,11 @@ public record EventNodeHeartbeat(
     ) : BaseEvent();
 
 
-//    record EventNodeDeleted(
-//        Guid MachineId,
-//        Guid ScalesetId,
-//        PoolName PoolName
-//        ) : BaseEvent();
+public record EventNodeDeleted(
+    Guid MachineId,
+    Guid? ScalesetId,
+    PoolName PoolName
+) : BaseEvent();
 
 
 public record EventScalesetStateUpdated(

src/ApiService/ApiService/OneFuzzTypes/Model.cs

@@ -70,19 +70,8 @@ public record NodeTasks
     Guid MachineId,
     Guid TaskId,
     NodeTaskState State = NodeTaskState.Init
-);
+) : StatefulEntityBase<NodeTaskState>(State);
 
-public enum NodeState {
-    Init,
-    Free,
-    SettingUp,
-    Rebooting,
-    Ready,
-    Busy,
-    Done,
-    Shutdown,
-    Halt,
-}
 
 public record ProxyHeartbeat
 (

src/ApiService/ApiService/Program.cs

@@ -88,6 +88,9 @@ public class Program {
             .AddScoped<ILogAnalytics, LogAnalytics>()
             .AddScoped<IExtensions, Extensions>()
             .AddScoped<IVmssOperations, VmssOperations>()
+            .AddScoped<INodeTasksOperations, NodeTasksOperations>()
+            .AddScoped<INodeMessageOperations, NodeMessageOperations>()
+
             .AddSingleton<ICreds, Creds>()
             .AddSingleton<IServiceConfig, ServiceConfiguration>()
             .AddHttpClient()

src/ApiService/ApiService/TimerWorkers.cs

@@ -0,0 +1,40 @@
+namespace Microsoft.OneFuzz.Service;
+
+public class TimerWorkers {
+    ILogTracer _log;
+    IScalesetOperations _scaleSetOps;
+
+    public TimerWorkers(ILogTracer log, IScalesetOperations scaleSetOps) {
+        _log = log;
+        _scaleSetOps = scaleSetOps;
+    }
+
+    void ProcessScaleSets(Scaleset scaleset) {
+        _log.Verbose($"checking scaleset for updates: {scaleset.ScalesetId}");
+
+        _scaleSetOps.UpdateConfigs(scaleset);
+
+
+
+    }
+
+
+    //public async Async.Task Run([TimerTrigger("00:01:30")] TimerInfo t) {
+    // NOTE: Update pools first, such that scalesets impacted by pool updates
+    // (such as shutdown or resize) happen during this iteration `timer_worker`
+    // rather than the following iteration.
+
+
+
+
+    // NOTE: Nodes, and Scalesets should be processed in a consistent order such
+    // during 'pool scale down' operations. This means that pools that are
+    // scaling down will more likely remove from the same scalesets over time.
+    // By more likely removing from the same scalesets, we are more likely to
+    // get to empty scalesets, which can safely be deleted.
+
+
+    //}
+
+
+}

src/ApiService/ApiService/onefuzzlib/Events.cs

@@ -1,5 +1,4 @@
-using System.Text;
-using System.Text.Json;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 using Microsoft.OneFuzz.Service.OneFuzzLib.Orm;
 
@@ -32,8 +31,7 @@ namespace Microsoft.OneFuzz.Service {
 
         public async Async.Task QueueSignalrEvent(EventMessage eventMessage) {
             var message = new SignalREvent("events", new List<EventMessage>() { eventMessage });
-            var encodedMessage = Encoding.UTF8.GetBytes(JsonSerializer.Serialize(message));
-            await _queue.SendMessage("signalr-events", encodedMessage, StorageType.Config);
+            await _queue.SendMessage("signalr-events", JsonSerializer.Serialize(message), StorageType.Config);
         }
 
         public async Async.Task SendEvent(BaseEvent anEvent) {

src/ApiService/ApiService/onefuzzlib/NodeOperations.cs

@@ -1,17 +1,45 @@
-using System.Threading.Tasks;
+using System.Text.Json;
+using System.Threading.Tasks;
 using ApiService.OneFuzzLib.Orm;
+using Microsoft.OneFuzz.Service.OneFuzzLib.Orm;
 
 namespace Microsoft.OneFuzz.Service;
 
 public interface INodeOperations : IStatefulOrm<Node, NodeState> {
     Task<Node?> GetByMachineId(Guid machineId);
+
+    IAsyncEnumerable<Node> SearchStates(Guid? poolId = default,
+        Guid? scaleSetId = default,
+        IList<NodeState>? states = default,
+        string? poolName = default,
+        bool excludeUpdateScheduled = false,
+        int? numResults = default);
+
+    new Async.Task Delete(Node node);
 }
 
 public class NodeOperations : StatefulOrm<Node, NodeState>, INodeOperations {
 
-    public NodeOperations(IStorage storage, ILogTracer log, IServiceConfig config)
+    private readonly INodeTasksOperations _nodeTasksOps;
+    private readonly ITaskOperations _taskOps;
+    private readonly INodeMessageOperations _nodeMessageOps;
+    private readonly IEvents _events;
+
+    public NodeOperations(
+        IStorage storage,
+        ILogTracer log,
+        IServiceConfig config,
+        ITaskOperations taskOps,
+        INodeTasksOperations nodeTasksOps,
+        INodeMessageOperations nodeMessageOps,
+        IEvents events
+        )
         : base(storage, log, config) {
 
+        _taskOps = taskOps;
+        _nodeTasksOps = nodeTasksOps;
+        _nodeMessageOps = nodeMessageOps;
+        _events = events;
     }
 
     public async Task<Node?> GetByMachineId(Guid machineId) {
@@ -20,4 +48,174 @@ public class NodeOperations : StatefulOrm<Node, NodeState>, INodeOperations {
         return await data.FirstOrDefaultAsync();
     }
 
+    public static string SearchStatesQuery(
+        string oneFuzzVersion,
+        Guid? poolId = default,
+        Guid? scaleSetId = default,
+        IEnumerable<NodeState>? states = default,
+        string? poolName = default,
+        bool excludeUpdateScheduled = false,
+        int? numResults = default) {
+
+        List<string> queryParts = new();
+
+        if (poolId is not null) {
+            queryParts.Add($"(pool_id eq '{poolId}')");
+        }
+
+        if (scaleSetId is not null) {
+            queryParts.Add($"(scaleset_id eq '{scaleSetId}')");
+        }
+
+        if (states is not null) {
+            IEnumerable<string> convertedStates = states.Select(x => JsonSerializer.Serialize(x, EntityConverter.GetJsonSerializerOptions()).Trim('"'));
+            var q = Query.EqualAny("state", convertedStates);
+            queryParts.Add($"({q})");
+        }
+
+        if (excludeUpdateScheduled) {
+            queryParts.Add($"reimage_requested eq false");
+            queryParts.Add($"delete_requested eq false");
+        }
+
+        //# azure table query always return false when the column does not exist
+        //# We write the query this way to allow us to get the nodes where the
+        //# version is not defined as well as the nodes with a mismatched version
+        var versionQuery = $"not (version eq '{oneFuzzVersion}')";
+        queryParts.Add(versionQuery);
+
+        return Query.And(queryParts);
+    }
+
+
+    public IAsyncEnumerable<Node> SearchStates(
+        Guid? poolId = default,
+        Guid? scaleSetId = default,
+        IList<NodeState>? states = default,
+        string? poolName = default,
+        bool excludeUpdateScheduled = false,
+        int? numResults = default) {
+        var query = NodeOperations.SearchStatesQuery(_config.OneFuzzVersion, poolId, scaleSetId, states, poolName, excludeUpdateScheduled, numResults);
+        return QueryAsync(query);
+    }
+
+    public async Async.Task MarkTasksStoppedEarly(Node node, Error? error = null) {
+        if (error is null) {
+            error = new Error(ErrorCode.TASK_FAILED, new[] { $"node reimaged during task execution.  machine_id: {node.MachineId}" });
+        }
+
+        await foreach (var entry in _nodeTasksOps.GetByMachineId(node.MachineId)) {
+            var task = await _taskOps.GetByTaskId(entry.TaskId);
+            if (task is not null) {
+                await _taskOps.MarkFailed(task, error);
+            }
+            if (!node.DebugKeepNode) {
+                await Delete(node);
+            }
+        }
+    }
+
+    public new async Async.Task Delete(Node node) {
+        await MarkTasksStoppedEarly(node);
+        await _nodeTasksOps.ClearByMachineId(node.MachineId);
+        await _nodeMessageOps.ClearMessages(node.MachineId);
+        await base.Delete(node);
+
+        await _events.SendEvent(new EventNodeDeleted(node.MachineId, node.ScalesetId, node.PoolName));
+    }
+}
+
+
+public interface INodeTasksOperations : IStatefulOrm<NodeTasks, NodeTaskState> {
+    IAsyncEnumerable<Node> GetNodesByTaskId(Guid taskId, INodeOperations nodeOps);
+    IAsyncEnumerable<NodeAssignment> GetNodeAssignments(Guid taskId, INodeOperations nodeOps);
+    IAsyncEnumerable<NodeTasks> GetByMachineId(Guid machineId);
+    IAsyncEnumerable<NodeTasks> GetByTaskId(Guid taskId);
+    Async.Task ClearByMachineId(Guid machineId);
+}
+
+public class NodeTasksOperations : StatefulOrm<NodeTasks, NodeTaskState>, INodeTasksOperations {
+
+    ILogTracer _log;
+
+    public NodeTasksOperations(IStorage storage, ILogTracer log, IServiceConfig config)
+        : base(storage, log, config) {
+        _log = log;
+    }
+
+    //TODO: suggest by Cheick: this can probably be optimize by query all NodesTasks then query the all machine in single request
+    public async IAsyncEnumerable<Node> GetNodesByTaskId(Guid taskId, INodeOperations nodeOps) {
+        List<Node> results = new();
+        await foreach (var entry in QueryAsync($"task_id eq '{taskId}'")) {
+            var node = await nodeOps.GetByMachineId(entry.MachineId);
+            if (node is not null) {
+                yield return node;
+            }
+        }
+    }
+    public async IAsyncEnumerable<NodeAssignment> GetNodeAssignments(Guid taskId, INodeOperations nodeOps) {
+
+        await foreach (var entry in QueryAsync($"task_id eq '{taskId}'")) {
+            var node = await nodeOps.GetByMachineId(entry.MachineId);
+            if (node is not null) {
+                var nodeAssignment = new NodeAssignment(node.MachineId, node.ScalesetId, entry.State);
+                yield return nodeAssignment;
+            }
+        }
+    }
+
+    public IAsyncEnumerable<NodeTasks> GetByMachineId(Guid machineId) {
+        return QueryAsync($"macine_id eq '{machineId}'");
+    }
+
+    public IAsyncEnumerable<NodeTasks> GetByTaskId(Guid taskId) {
+        return QueryAsync($"task_id eq '{taskId}'");
+    }
+
+    public async Async.Task ClearByMachineId(Guid machineId) {
+        _log.Info($"clearing tasks for node {machineId}");
+        await foreach (var entry in GetByMachineId(machineId)) {
+            var res = await Delete(entry);
+            if (!res.IsOk) {
+                _log.Error($"failed to delete node task entry for machine_id: {entry.MachineId} due to [{res.ErrorV.Item1}] {res.ErrorV.Item2}");
+            }
+        }
+    }
+}
+
+//# this isn't anticipated to be needed by the client, hence it not
+//# being in onefuzztypes
+public record NodeMessage(
+    [PartitionKey] Guid MachineId,
+    [RowKey] string MessageId,
+    NodeCommand Message
+) : EntityBase;
+
+public interface INodeMessageOperations : IOrm<NodeMessage> {
+    IAsyncEnumerable<NodeMessage> GetMessage(Guid machineId);
+    Async.Task ClearMessages(Guid machineId);
+}
+
+
+public class NodeMessageOperations : Orm<NodeMessage>, INodeMessageOperations {
+
+    private readonly ILogTracer _log;
+    public NodeMessageOperations(IStorage storage, ILogTracer log, IServiceConfig config) : base(storage, log, config) {
+        _log = log;
+    }
+
+    public IAsyncEnumerable<NodeMessage> GetMessage(Guid machineId) {
+        return QueryAsync($"machine_id eq '{machineId}'");
+    }
+
+    public async Async.Task ClearMessages(Guid machineId) {
+        _log.Info($"clearing messages for node {machineId}");
+
+        await foreach (var message in GetMessage(machineId)) {
+            var r = await Delete(message);
+            if (!r.IsOk) {
+                _log.Error($"failed to delete message for node {machineId} due to [{r.ErrorV.Item1}] {r.ErrorV.Item2}");
+            }
+        }
+    }
 }

src/ApiService/ApiService/onefuzzlib/NotificationOperations.cs

@@ -65,7 +65,7 @@ public class NotificationOperations : Orm<Notification>, INotificationOperations
             if (containers.Contains(container.ContainerName)) {
                 _logTracer.Info($"queuing input {container.ContainerName} {filename} {task.TaskId}");
                 var url = _containers.GetFileSasUrl(container, filename, StorageType.Corpus, BlobSasPermissions.Read | BlobSasPermissions.Delete);
-                await _queue.SendMessage(task.TaskId.ToString(), System.Text.Encoding.UTF8.GetBytes(url?.ToString() ?? ""), StorageType.Corpus);
+                await _queue.SendMessage(task.TaskId.ToString(), url?.ToString() ?? "", StorageType.Corpus);
             }
         }
 

src/ApiService/ApiService/onefuzzlib/Queue.cs

@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Threading.Tasks;
+using Azure.Core;
 using Azure.Storage;
 using Azure.Storage.Queues;
 using Azure.Storage.Sas;
@@ -7,9 +8,15 @@ using Microsoft.OneFuzz.Service.OneFuzzLib.Orm;
 
 namespace Microsoft.OneFuzz.Service;
 public interface IQueue {
-    Async.Task SendMessage(string name, byte[] message, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null);
-    Async.Task<bool> QueueObject<T>(string name, T obj, StorageType storageType, TimeSpan? visibilityTimeout = null);
+    Async.Task SendMessage(string name, string message, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null);
+    Async.Task<bool> QueueObject<T>(string name, T obj, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null);
     Async.Task<Uri?> GetQueueSas(string name, StorageType storageType, QueueSasPermissions permissions, TimeSpan? duration = null);
+    ResourceIdentifier GeResourceId(string queueName, StorageType storageType);
+    Task<IList<T>> PeekQueue<T>(string name, StorageType storageType);
+    Async.Task<bool> RemoveFirstMessage(string name, StorageType storageType);
+    Async.Task ClearQueue(string name, StorageType storageType);
+    Async.Task DeleteQueue(string name, StorageType storageType);
+    Async.Task CreateQueue(string name, StorageType storageType);
 }
 
 
@@ -25,41 +32,123 @@ public class Queue : IQueue {
     }
 
 
-    public async Async.Task SendMessage(string name, byte[] message, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null) {
-        var queue = await GetQueue(name, storageType);
-        if (queue != null) {
-            await queue.SendMessageAsync(Convert.ToBase64String(message), visibilityTimeout: visibilityTimeout, timeToLive: timeToLive);
+    public async Async.Task SendMessage(string name, string message, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null) {
+        var queue = await GetQueueClient(name, storageType);
+        try {
+            await queue.SendMessageAsync(message, visibilityTimeout: visibilityTimeout, timeToLive: timeToLive);
+        } catch (Exception ex) {
+            _log.Exception(ex, $"Failed to send message {message}");
+            throw;
         }
     }
 
-    public async Task<QueueClient?> GetQueue(string name, StorageType storageType) {
-        var client = await GetQueueClient(storageType);
+    public async Task<QueueClient> GetQueueClient(string name, StorageType storageType) {
+        var client = await GetQueueClientService(storageType);
         return client.GetQueueClient(name);
     }
 
-
-    public async Task<QueueServiceClient> GetQueueClient(StorageType storageType) {
+    public async Task<QueueServiceClient> GetQueueClientService(StorageType storageType) {
         var accountId = _storage.GetPrimaryAccount(storageType);
-        //_logger.LogDEbug("getting blob container (account_id: %s)", account_id)
+        _log.Verbose($"getting blob container (account_id: {accountId})");
         var (name, key) = await _storage.GetStorageAccountNameAndKey(accountId);
         var accountUrl = new Uri($"https://{name}.queue.core.windows.net");
-        var client = new QueueServiceClient(accountUrl, new StorageSharedKeyCredential(name, key));
-        return client;
+        var options = new QueueClientOptions { MessageEncoding = QueueMessageEncoding.Base64 };
+        return new QueueServiceClient(accountUrl, new StorageSharedKeyCredential(name, key), options);
     }
 
-    public async Task<bool> QueueObject<T>(string name, T obj, StorageType storageType, TimeSpan? visibilityTimeout) {
-        var queue = await GetQueue(name, storageType) ?? throw new Exception($"unable to queue object, no such queue: {name}");
-
+    public async Task<bool> QueueObject<T>(string name, T obj, StorageType storageType, TimeSpan? visibilityTimeout = null, TimeSpan? timeToLive = null) {
+        var queueClient = await GetQueueClient(name, storageType) ?? throw new Exception($"unable to queue object, no such queue: {name}");
+        try {
             var serialized = JsonSerializer.Serialize(obj, EntityConverter.GetJsonSerializerOptions());
-        //var encoded = Encoding.UTF8.GetBytes(serialized);
-        var response = await queue.SendMessageAsync(serialized, visibilityTimeout: visibilityTimeout);
-        return !response.GetRawResponse().IsError;
+            var res = await queueClient.SendMessageAsync(serialized, visibilityTimeout: visibilityTimeout, timeToLive);
+            if (res.GetRawResponse().IsError) {
+                _log.Error($"Failed to send message {serialized} in queue {name} due to {res.GetRawResponse().ReasonPhrase}");
+                return false;
+            } else {
+                return true;
+            }
+        } catch (Exception ex) {
+            _log.Exception(ex, $"Failed to queue message in queue {name}");
+            return false;
+        }
     }
 
     public async Task<Uri?> GetQueueSas(string name, StorageType storageType, QueueSasPermissions permissions, TimeSpan? duration) {
-        var queue = await GetQueue(name, storageType) ?? throw new Exception($"unable to queue object, no such queue: {name}");
+        var queue = await GetQueueClient(name, storageType) ?? throw new Exception($"unable to queue object, no such queue: {name}");
         var sasaBuilder = new QueueSasBuilder(permissions, DateTimeOffset.UtcNow + (duration ?? DEFAULT_DURATION));
         var url = queue.GenerateSasUri(sasaBuilder);
         return url;
     }
+
+
+    public async Async.Task CreateQueue(string name, StorageType storageType) {
+        var client = await GetQueueClient(name, storageType);
+        var resp = await client.CreateIfNotExistsAsync();
+
+        if (resp.IsError) {
+            _log.Error($"failed to create queue {name} due to {resp.ReasonPhrase}");
+        }
+    }
+
+    public async Async.Task DeleteQueue(string name, StorageType storageType) {
+        var client = await GetQueueClient(name, storageType);
+        var resp = await client.DeleteIfExistsAsync();
+        if (resp.GetRawResponse().IsError) {
+            _log.Error($"failed to delete queue {name} due to {resp.GetRawResponse().ReasonPhrase}");
+        }
+    }
+
+    public async Async.Task ClearQueue(string name, StorageType storageType) {
+        var client = await GetQueueClient(name, storageType);
+        var resp = await client.ClearMessagesAsync();
+        if (resp.IsError) {
+            _log.Error($"failed to clear the queue {name} due to {resp.ReasonPhrase}");
+        }
+    }
+
+    public async Async.Task<bool> RemoveFirstMessage(string name, StorageType storageType) {
+        var client = await GetQueueClient(name, storageType);
+
+        var msgs = await client.ReceiveMessagesAsync();
+        foreach (var msg in msgs.Value) {
+            var resp = await client.DeleteMessageAsync(msg.MessageId, msg.PopReceipt);
+            if (resp.IsError) {
+                _log.Error($"failed to delete message from the queue {name} due to {resp.ReasonPhrase}");
+                return false;
+            } else {
+                return true;
+            }
+        }
+        return false; ;
+    }
+
+    public async Task<IList<T>> PeekQueue<T>(string name, StorageType storageType) {
+        var client = await GetQueueClient(name, storageType);
+
+        var result = new List<T>();
+
+        var msgs = await client.PeekMessagesAsync(client.MaxPeekableMessages);
+        if (msgs is null) {
+            return result;
+        } else if (msgs.GetRawResponse().IsError) {
+
+            _log.Error($"failed to peek messages due to {msgs.GetRawResponse().ReasonPhrase}");
+            return result;
+        } else {
+            foreach (var msg in msgs.Value) {
+
+                var obj = JsonSerializer.Deserialize<T>(msg.Body.ToString(), EntityConverter.GetJsonSerializerOptions());
+                if (obj is not null) {
+                    result.Add(obj);
+                }
+            }
+        }
+        return result;
+    }
+
+    public ResourceIdentifier GeResourceId(string queueName, StorageType storageType) {
+        var account = _storage.GetPrimaryAccount(storageType);
+        return new ResourceIdentifier($"{account}/services/queue/queues/{queueName}");
+    }
+
 }

src/ApiService/ApiService/onefuzzlib/ScalesetOperations.cs

@@ -17,14 +17,18 @@ public class ScalesetOperations : StatefulOrm<Scaleset, ScalesetState>, IScalese
     IEvents _events;
     IExtensions _extensions;
     IVmssOperations _vmssOps;
+    IQueue _queue;
+    INodeOperations _nodeOps;
 
-    public ScalesetOperations(IStorage storage, ILogTracer log, IServiceConfig config, IPoolOperations poolOps, IEvents events, IExtensions extensions, IVmssOperations vmssOps)
+    public ScalesetOperations(IStorage storage, ILogTracer log, IServiceConfig config, IPoolOperations poolOps, IEvents events, IExtensions extensions, IVmssOperations vmssOps, IQueue queue, INodeOperations nodeOps)
         : base(storage, log, config) {
         _log = log;
         _poolOps = poolOps;
         _events = events;
         _extensions = extensions;
         _vmssOps = vmssOps;
+        _queue = queue;
+        _nodeOps = nodeOps;
     }
 
     public IAsyncEnumerable<Scaleset> Search() {
@@ -87,7 +91,7 @@ public class ScalesetOperations : StatefulOrm<Scaleset, ScalesetState>, IScalese
         var pool = await _poolOps.GetByName(scaleSet.PoolName);
 
         if (!pool.IsOk || pool.OkV is null) {
-            _log.Error($"{SCALESET_LOG_PREFIX}: unable to find pool during config update. pool:{scaleSet.PoolName}, scaleset_id:{scaleSet.ScalesetId}");
+            _log.Error($"{SCALESET_LOG_PREFIX} unable to find pool during config update. pool:{scaleSet.PoolName}, scaleset_id:{scaleSet.ScalesetId}");
             await SetFailed(scaleSet, pool.ErrorV!);
             return;
         }
@@ -97,7 +101,44 @@ public class ScalesetOperations : StatefulOrm<Scaleset, ScalesetState>, IScalese
         var res = await _vmssOps.UpdateExtensions(scaleSet.ScalesetId, extensions);
 
         if (!res.IsOk) {
-            _log.Info($"{SCALESET_LOG_PREFIX}: unable to update configs {string.Join(',', res.ErrorV.Errors!)}");
+            _log.Info($"{SCALESET_LOG_PREFIX} unable to update configs {string.Join(',', res.ErrorV.Errors!)}");
         }
     }
+
+
+    public async Async.Task Halt(Scaleset scaleset) {
+        var shrinkQueue = new ShrinkQueue(scaleset.ScalesetId, _queue, _log);
+        await shrinkQueue.Delete();
+
+        await foreach (var node in _nodeOps.SearchStates(scaleSetId: scaleset.ScalesetId)) {
+            _log.Info($"{SCALESET_LOG_PREFIX} deleting node scaleset_id {scaleset.ScalesetId} machine_id {node.MachineId}");
+
+
+        }
+        //_nodeOps.
+
+
+    }
+
+
+    /// <summary>
+    /// Cleanup scaleset nodes
+    /// </summary>
+    /// <param name="scaleSet"></param>
+    /// <returns>true if scaleset got modified</returns>
+    public async Async.Task<bool> CleanupNodes(Scaleset scaleSet) {
+        _log.Info($"{SCALESET_LOG_PREFIX} cleaning up nodes. scaleset_id {scaleSet.ScalesetId}");
+
+        if (scaleSet.State == ScalesetState.Halt) {
+            _log.Info($"{SCALESET_LOG_PREFIX} halting scaleset scaleset_id {scaleSet.ScalesetId}");
+
+            await Halt(scaleSet);
+
+            return true;
+        }
+
+        throw new NotImplementedException();
+    }
+
+
 }

src/ApiService/ApiService/onefuzzlib/ShrinkQueue.cs

@@ -0,0 +1,58 @@
+namespace Microsoft.OneFuzz.Service;
+
+public record ShrinkEntry(Guid ShrinkId);
+
+
+public class ShrinkQueue {
+    Guid _baseId;
+    IQueue _queueOps;
+    ILogTracer _log;
+
+    public ShrinkQueue(Guid baseId, IQueue queueOps, ILogTracer log) {
+        _baseId = baseId;
+        _queueOps = queueOps;
+        _log = log;
+    }
+
+    public override string ToString() {
+        return $"to-shrink-{_baseId.ToString("N")}";
+    }
+    public string QueueName => this.ToString();
+
+    public async Async.Task Clear() {
+        await _queueOps.ClearQueue(QueueName, StorageType.Config);
+    }
+
+    public async Async.Task Create() {
+        await _queueOps.CreateQueue(QueueName, StorageType.Config);
+    }
+
+    public async Async.Task Delete() {
+        await _queueOps.DeleteQueue(QueueName, StorageType.Config);
+    }
+
+    public async Async.Task<bool> AddEntry() {
+        return await _queueOps.QueueObject<ShrinkEntry>(QueueName, new ShrinkEntry(Guid.NewGuid()), StorageType.Config);
+    }
+
+    public async Async.Task SetSize(int size) {
+        await Clear();
+        var i = 0;
+
+        while (i < size) {
+            var r = await AddEntry();
+            if (r) {
+                i++;
+            } else {
+                //TODO: retry after a delay ? I guess make a decision on this
+                //if we hit this error message... For now just log and move on to
+                //make it behave same as Python code.
+                _log.Error($"failed to add entry to shrink queue");
+                i++;
+            }
+        }
+
+    }
+
+
+}

src/ApiService/ApiService/onefuzzlib/TaskOperations.cs

@@ -14,6 +14,8 @@ public interface ITaskOperations : IStatefulOrm<Task, TaskState> {
 
     IAsyncEnumerable<Task> SearchExpired();
     Async.Task MarkStopping(Task task);
+    Async.Task MarkFailed(Task task, Error error, List<Task>? taskInJob = null);
+
     Async.Task<TaskVm?> GetReproVmConfig(Task task);
     Async.Task<bool> CheckPrereqTasks(Task task);
     System.Threading.Tasks.Task<Pool?> GetPool(Task task);

src/ApiService/ApiService/onefuzzlib/orm/Queries.cs

@@ -0,0 +1,17 @@
+namespace ApiService.OneFuzzLib.Orm {
+    public static class Query {
+
+        public static string Or(IEnumerable<string> queries) {
+            return string.Join(" or ", queries.Select(x => $"({x})"));
+        }
+
+        public static string And(IEnumerable<string> queries) {
+            return string.Join(" and ", queries.Select(x => $"({x})"));
+        }
+
+        public static string EqualAny(string property, IEnumerable<string> values) {
+            return Or(values.Select(x => $"{property} eq '{x}'"));
+        }
+
+    }
+}

src/ApiService/Tests/OrmModelsTest.cs

@@ -24,6 +24,13 @@ namespace Tests {
                 Arb.Generate<EventCrashReported>().Select(e => e as BaseEvent),
                 Arb.Generate<EventRegressionReported>().Select(e => e as BaseEvent),
                 Arb.Generate<EventFileAdded>().Select(e => e as BaseEvent),
+                Arb.Generate<EventTaskFailed>().Select(e => e as BaseEvent),
+                Arb.Generate<EventTaskStopped>().Select(e => e as BaseEvent),
+                Arb.Generate<EventTaskStateUpdated>().Select(e => e as BaseEvent),
+                Arb.Generate<EventScalesetFailed>().Select(e => e as BaseEvent),
+                Arb.Generate<EventScalesetResizeScheduled>().Select(e => e as BaseEvent),
+                Arb.Generate<EventScalesetStateUpdated>().Select(e => e as BaseEvent),
+                Arb.Generate<EventNodeDeleted>().Select(e => e as BaseEvent),
             });
         }
 
@@ -47,6 +54,17 @@ namespace Tests {
             ));
         }
 
+        public static Gen<NodeTasks> NodeTasks() {
+            return Arb.Generate<Tuple<Guid, Guid, NodeTaskState>>().Select(
+                arg =>
+                    new NodeTasks(
+                        MachineId: arg.Item1,
+                        TaskId: arg.Item2,
+                        State: arg.Item3
+                    )
+            );
+        }
+
         public static Gen<Node> Node() {
             return Arb.Generate<Tuple<Tuple<DateTimeOffset?, string, Guid?, Guid, NodeState>, Tuple<Guid?, DateTimeOffset, string, bool, bool, bool>>>().Select(
                 arg => new Node(
@@ -311,6 +329,10 @@ namespace Tests {
             return Arb.From(OrmGenerators.BaseEvent());
         }
 
+        public static Arbitrary<NodeTasks> NodeTasks() {
+            return Arb.From(OrmGenerators.NodeTasks());
+        }
+
         public static Arbitrary<Node> Node() {
             return Arb.From(OrmGenerators.Node());
         }

src/ApiService/Tests/QueryTest.cs

@@ -0,0 +1,37 @@
+using System;
+using Microsoft.OneFuzz.Service;
+using Xunit;
+
+
+namespace Tests {
+
+    public class QueryTests {
+
+        [Fact]
+        public void NodeOperationsSearchStatesQuery() {
+
+            var query1 = NodeOperations.SearchStatesQuery("1.2.3");
+            Assert.Equal("(not (version eq '1.2.3'))", query1);
+
+            var query2 = NodeOperations.SearchStatesQuery("1.2.3", poolId: Guid.Parse("3b0426d3-9bde-4ae8-89ac-4edf0d3b3618"));
+            Assert.Equal("((pool_id eq '3b0426d3-9bde-4ae8-89ac-4edf0d3b3618')) and (not (version eq '1.2.3'))", query2);
+
+            var query3 = NodeOperations.SearchStatesQuery("1.2.3", scaleSetId: Guid.Parse("4c96dd6b-9bdb-4758-9720-1010c244fa4b"));
+            Assert.Equal("((scaleset_id eq '4c96dd6b-9bdb-4758-9720-1010c244fa4b')) and (not (version eq '1.2.3'))", query3);
+
+            var query4 = NodeOperations.SearchStatesQuery("1.2.3", states: new[] { NodeState.Free, NodeState.Done, NodeState.Ready });
+            Assert.Equal("(((state eq 'free') or (state eq 'done') or (state eq 'ready'))) and (not (version eq '1.2.3'))", query4);
+
+            var query5 = NodeOperations.SearchStatesQuery("1.2.3", excludeUpdateScheduled: true);
+            Assert.Equal("(reimage_requested eq false) and (delete_requested eq false) and (not (version eq '1.2.3'))", query5);
+
+            var query7 = NodeOperations.SearchStatesQuery(
+                            "1.2.3",
+                            poolId: Guid.Parse("3b0426d3-9bde-4ae8-89ac-4edf0d3b3618"),
+                            scaleSetId: Guid.Parse("4c96dd6b-9bdb-4758-9720-1010c244fa4b"),
+                            states: new[] { NodeState.Free, NodeState.Done, NodeState.Ready },
+                            excludeUpdateScheduled: true);
+            Assert.Equal("((pool_id eq '3b0426d3-9bde-4ae8-89ac-4edf0d3b3618')) and ((scaleset_id eq '4c96dd6b-9bdb-4758-9720-1010c244fa4b')) and (((state eq 'free') or (state eq 'done') or (state eq 'ready'))) and (reimage_requested eq false) and (delete_requested eq false) and (not (version eq '1.2.3'))", query7);
+        }
+    }
+}