Merge pull request #44 from NoiTheCat/fixes/userdl-hang

Fix hanging, unnecessary disconnections when AutoUserDownload is hanging
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Noi 2023-03-09 12:34:30 -08:00 committed by GitHub
commit 0fe65b7e66
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3 changed files with 36 additions and 12 deletions

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@ -8,17 +8,27 @@ namespace BirthdayBot.BackgroundServices;
class AutoUserDownload : BackgroundService {
public AutoUserDownload(ShardInstance instance) : base(instance) { }
private static readonly HashSet<ulong> _failedDownloads = new();
private static readonly TimeSpan _singleDlTimeout = ShardManager.DeadShardThreshold / 3;
public override async Task OnTick(int tickCount, CancellationToken token) {
// Take action if a guild's cache is incomplete...
var incompleteCaches = ShardInstance.DiscordClient.Guilds.Where(g => !g.HasAllMembers).Select(g => g.Id).ToHashSet();
var incompleteCaches = ShardInstance.DiscordClient.Guilds
.Where(g => !g.HasAllMembers)
.Select(g => g.Id)
.ToHashSet();
// ...and if the guild contains any user data
IEnumerable<ulong> mustFetch;
try {
await DbConcurrentOperationsLock.WaitAsync(token);
using var db = new BotDatabaseContext();
mustFetch = db.UserEntries.AsNoTracking()
.Where(e => incompleteCaches.Contains(e.GuildId)).Select(e => e.GuildId).Distinct()
.ToList();
lock (_failedDownloads)
mustFetch = db.UserEntries.AsNoTracking()
.Where(e => incompleteCaches.Contains(e.GuildId))
.Select(e => e.GuildId)
.Distinct()
.Where(e => !_failedDownloads.Contains(e))
.ToList();
} finally {
try {
DbConcurrentOperationsLock.Release();
@ -26,17 +36,31 @@ class AutoUserDownload : BackgroundService {
}
var processed = 0;
var processStartTime = DateTimeOffset.UtcNow;
foreach (var item in mustFetch) {
// May cause a disconnect in certain situations. Cancel all further attempts until the next pass if it happens.
// May cause a disconnect in certain situations. Make no further attempts until the next pass if it happens.
if (ShardInstance.DiscordClient.ConnectionState != ConnectionState.Connected) break;
var guild = ShardInstance.DiscordClient.GetGuild((ulong)item);
var guild = ShardInstance.DiscordClient.GetGuild(item);
if (guild == null) continue; // A guild disappeared...?
await guild.DownloadUsersAsync().ConfigureAwait(false); // We're already on a seperate thread, no need to use Task.Run
await Task.Delay(200, CancellationToken.None).ConfigureAwait(false); // Must delay, or else it seems to hang...
await Task.Delay(200, CancellationToken.None); // Delay a bit (reduces the possibility of hanging, somehow).
processed++;
var dl = guild.DownloadUsersAsync();
dl.Wait((int)_singleDlTimeout.TotalMilliseconds / 2, token);
if (dl.IsFaulted) {
Log("Exception thrown by download task: " + dl.Exception);
break;
} else if (!dl.IsCompletedSuccessfully) {
Log($"Task for guild {guild.Id} is unresponsive. Skipping guild. Members: {guild.MemberCount}. Name: {guild.Name}.");
lock (_failedDownloads) _failedDownloads.Add(guild.Id);
continue;
}
// Prevent unnecessary disconnections by ShardManager if we're taking too long
if (DateTimeOffset.UtcNow - processStartTime > _singleDlTimeout) break;
}
if (processed > 25) Log($"Explicit user list request processed for {processed} guild(s).");
if (processed > 10) Log($"Member list downloads handled for {processed} guilds.");
}
}

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@ -5,7 +5,7 @@
<TargetFramework>net6.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
<Version>3.4.7</Version>
<Version>3.4.8</Version>
<Authors>NoiTheCat</Authors>
</PropertyGroup>
@ -22,7 +22,7 @@
<ItemGroup>
<PackageReference Include="CommandLineParser" Version="2.9.1" />
<PackageReference Include="Discord.Net" Version="3.8.1" />
<PackageReference Include="Discord.Net" Version="3.9.0" />
<PackageReference Include="EFCore.NamingConventions" Version="7.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="7.0.0">
<PrivateAssets>all</PrivateAssets>

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@ -25,7 +25,7 @@ class ShardManager : IDisposable {
/// Amount of time without a completed background service run before a shard instance
/// is considered "dead" and tasked to be removed.
/// </summary>
private static readonly TimeSpan DeadShardThreshold = new(0, 20, 0);
public static readonly TimeSpan DeadShardThreshold = new(0, 20, 0);
/// <summary>
/// A dictionary with shard IDs as its keys and shard instances as its values.