#6816 Akka.DistributedData.LightningDb: move durable folder creation outside of actor constructor

src/contrib/cluster/Akka.DistributedData.LightningDB/LmdbDurableStore.cs

@@ -56,7 +56,8 @@ private WriteBehind() { }
         private readonly long _mapSize;
 
         private readonly TimeSpan _writeBehindInterval;
-        private readonly string _dir;
+        private readonly string _path;
+        private string _dir;
 
         private readonly Dictionary<string, DurableDataEnvelope> _pending = new();
         private readonly ILoggingAdapter _log;
@@ -81,17 +82,8 @@ useWriteBehind is "off" or "false" or "no" ?
 
             _mapSize = _config.GetByteSize("map-size") ?? 100 * 1024 * 1024;
 
-            var path = _config.GetString("dir");
-            _dir = path.EndsWith(DatabaseName)
-                ? Path.GetFullPath($"{path}-{Context.System.Name}-{Self.Path.Parent.Name}-{Cluster.Cluster.Get(Context.System).SelfAddress.Port}")
-                : Path.GetFullPath(path);
+            _path = _config.GetString("dir");
 
-            if (!Directory.Exists(_dir))
-            {
-                Directory.CreateDirectory(_dir);
-            }
-
-            _log.Info($"Using durable data in LMDB directory [{_dir}]");
             Init();
         }
 
@@ -108,9 +100,23 @@ protected override void PostStop()
             DoWriteBehind();
         }
 
+        protected override void PreStart()
+        {
+            base.PreStart();
+
+            _dir = _path.EndsWith(DatabaseName)
+                ? Path.GetFullPath($"{_path}-{Context.System.Name}-{Self.Path.Parent.Name}-{Cluster.Cluster.Get(Context.System).SelfAddress.Port}")
+                : Path.GetFullPath(_path);
+            if (!Directory.Exists(_dir))
+                Directory.CreateDirectory(_dir);
+
+            _log.Info($"Using durable data in LMDB directory [{_dir}]");
+        }
+
         private LightningEnvironment GetLightningEnvironment()
         {
-            var t0 = Stopwatch.StartNew();
+            var t0 = Stopwatch.StartNew();      
+
             var env = new LightningEnvironment(_dir)
             {
                 MapSize = _mapSize,
@@ -181,13 +187,6 @@ private void Init()
         {
             Receive<LoadAll>(_ =>
             {
-                if(_dir.Length == 0 || !Directory.Exists(_dir))
-                {
-                    // no files to load
-                    Sender.Tell(LoadAllCompleted.Instance);
-                    Become(Active);
-                    return;
-                }
 
                 var t0 = Stopwatch.StartNew();
 

src/contrib/cluster/Akka.DistributedData.Tests/LightningDb/BugFix6816.cs

@@ -0,0 +1,88 @@
+//-----------------------------------------------------------------------
+// <copyright file="BugFix6816.cs" company="Akka.NET Project">
+//     Copyright (C) 2009-2023 Lightbend Inc. <http://www.lightbend.com>
+//     Copyright (C) 2013-2023 .NET Foundation <https://github.com/akkadotnet/akka.net>
+// </copyright>
+//-----------------------------------------------------------------------
+
+using System;
+using System.IO;
+using Akka.Actor;
+using Akka.Configuration;
+using Akka.DistributedData.Durable;
+using Akka.DistributedData.LightningDB;
+using Akka.Event;
+using FluentAssertions;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Akka.DistributedData.Tests.LightningDb;
+
+[Collection("DistributedDataSpec")]
+public class BugFix6816: Akka.TestKit.Xunit2.TestKit
+{
+    private const string DDataDir = "thatdir";
+    private static readonly Config BaseConfig = ConfigurationFactory.ParseString(@"
+            akka.actor.provider = ""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
+            akka.remote.dot-netty.tcp.port = 0")
+        .WithFallback(DistributedData.DefaultConfig())
+        .WithFallback(TestKit.Xunit2.TestKit.DefaultConfig);
+
+    private static readonly Config LmdbDefaultConfig = ConfigurationFactory.ParseString($@"
+        lmdb {{
+            dir = {DDataDir}
+            map-size = 100 MiB
+            write-behind-interval = off
+        }}");
+
+    public BugFix6816(ITestOutputHelper output): base(BaseConfig, "LmdbDurableStoreSpec", output)
+    {
+    }
+
+    [Fact]
+    public void Lmdb_creates_directory_when_handling_first_message()
+    {
+        if (Directory.Exists(DDataDir))
+        {
+            var di = new DirectoryInfo(DDataDir);
+            di.Delete(true);
+        }
+
+        Directory.Exists(DDataDir).Should().BeFalse();
+        var lmdb = ActorOf(LmdbDurableStore.Props(LmdbDefaultConfig));
+        lmdb.Tell(LoadAll.Instance);          
+        AwaitCondition(() => HasMessages);
+        ExpectMsg<LoadAllCompleted>();
+        Directory.Exists(DDataDir).Should().BeTrue();
+    }
+
+    [Fact]
+    public void Lmdb_logs_meaningful_error_for_invalid_dir_path()
+    {
+        var invalidName = Environment.OSVersion.Platform is PlatformID.Win32NT 
+            ? "\"invalid?directory\"" : "/dev/null/illegal";
+
+        Directory.Exists(invalidName).Should().BeFalse();
+
+        var probe = CreateTestProbe();
+        Sys.EventStream.Subscribe(probe, typeof(Error));
+
+        var lmdb = ActorOf(LmdbDurableStore.Props(ConfigurationFactory.ParseString($@"
+        lmdb {{
+            dir = {invalidName}
+            map-size = 100 MiB
+            write-behind-interval = off
+        }}")));
+
+        //Expect meaningful error log
+        var err =probe.ExpectMsg<Error>();
+        err.Message.ToString().Should()
+            .NotContain("Error while creating actor instance of type Akka.DistributedData.LightningDB.LmdbDurableStore");
+        err.Cause.Should().BeOfType<ActorInitializationException>();
+        err.Cause.InnerException.Should().NotBeNull();
+        (err.Cause.InnerException is IOException or DirectoryNotFoundException or ArgumentException).Should().BeTrue();
+
+        Directory.Exists(invalidName).Should().BeFalse();
+    }
+
+}

src/contrib/cluster/Akka.DistributedData.Tests/LightningDb/LmdbDurableStoreSpec.cs

@@ -21,9 +21,7 @@ public class LmdbDurableStoreSpec
         private readonly ITestOutputHelper _output;
 
         private static readonly Config BaseConfig = ConfigurationFactory.ParseString($@"
-            akka.actor {{
-                provider=""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
-            }}
+            akka.actor.provider=""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
             akka.remote.dot-netty.tcp.port = 0
             akka.cluster.distributed-data.durable.lmdb {{
                 dir = {DDataDir}
@@ -46,14 +44,12 @@ public void Lmdb_should_not_throw_when_opening_existing_directory()
                 di.Delete(true);
             }
             Directory.CreateDirectory(DDataDir);
-
             var testKit = new TestKit.Xunit2.TestKit(BaseConfig, nameof(LmdbDurableStoreSpec), _output);
             var probe = testKit.CreateTestProbe();
-
             var config = testKit.Sys.Settings.Config.GetConfig("akka.cluster.distributed-data.durable");
             var lmdb = testKit.Sys.ActorOf(LmdbDurableStore.Props(config));
             lmdb.Tell(LoadAll.Instance, probe.Ref);
-
+            
             probe.ExpectMsg<LoadAllCompleted>();
         }
     }