feat(hls): register transcode sessions and renew their lease

A transcode that is not in the store is invisible to the other replicas, so the
HLS entry points have to publish and hold the lease themselves.

- register the play session in the store when ffmpeg starts
- renew the lease on a background loop and delete the session when it ends
- shorten segments and bound the playlist window when resuming a stored session
- add RecoverySegmentLengthSeconds and RecoverySegmentBufferCount encoding options
This commit is contained in:
2026-09-11 23:56:35 +10:00
parent c43992630e
commit 6ccabd4c72
4 changed files with 631 additions and 9 deletions
@@ -0,0 +1,259 @@
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Api.Controllers;
using MediaBrowser.Controller.MediaEncoding;
using Xunit;
namespace Jellyfin.Api.Tests.Controllers
{
/// <summary>
/// Tests for HA recovery scenarios that will be wired into <see cref="DynamicHlsController"/>
/// in Phase 5.2. These tests verify the <see cref="ITranscodeSessionStore"/> contract that
/// the controller will rely on for missing-local-job recovery, claim racing, and cleanup guarding.
/// </summary>
public class DynamicHlsHaTakeoverTests
{
private static TranscodeSession CreateSession(string id, string pod, DateTime leaseExpiry)
=> new TranscodeSession
{
PlaySessionId = id,
OwnerPod = pod,
LeaseExpiresUtc = leaseExpiry,
ManifestPath = $"/transcode/{id}/manifest.m3u8",
SegmentPathPrefix = $"/transcode/{id}/segment",
MediaSourceId = "media-source-1",
LastCompletedSegmentIndex = 3,
LastDurablePlaybackOffset = 18_000_000L,
};
/// <summary>
/// Missing-local-job + durable-manifest-present: the store returns the session so
/// the controller can serve the existing manifest instead of returning an error.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task DurableManifestPresent_WithLiveSession_StoreReturnsSession()
{
var store = new HaTestSessionStore();
var session = CreateSession("ha-session-1", "pod-a", DateTime.UtcNow.AddMinutes(5));
await store.SetAsync(session, TestContext.Current.CancellationToken);
// Simulate controller recovery: look up the session in the durable store.
var recovered = await store.TryGetAsync("ha-session-1", TestContext.Current.CancellationToken);
Assert.NotNull(recovered);
Assert.Equal("/transcode/ha-session-1/manifest.m3u8", recovered.ManifestPath);
}
/// <summary>
/// Claim-race between two concurrent requesters: only one wins
/// <see cref="ITranscodeSessionStore.TryTakeoverAsync"/>.
/// The other receives <c>false</c>, indicating it should redirect (302) or wait.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task ClaimRace_TwoConcurrentRequesters_OnlyOneWinsTakeover()
{
var store = new HaTestSessionStore();
// Original pod crashed – lease is expired.
var session = CreateSession("ha-session-2", "pod-a", DateTime.UtcNow.AddMilliseconds(-1));
await store.SetAsync(session, TestContext.Current.CancellationToken);
// Two pods simultaneously attempt to claim the orphaned session.
var task1 = store.TryTakeoverAsync("ha-session-2", "pod-b", TestContext.Current.CancellationToken);
var task2 = store.TryTakeoverAsync("ha-session-2", "pod-c", TestContext.Current.CancellationToken);
var results = await Task.WhenAll(task1, task2);
// Exactly one pod must win.
var wins = Array.FindAll(results, r => r);
Assert.Single(wins);
}
/// <summary>
/// Stale-manifest cleanup guard: a lease that has expired beyond the recovery window
/// causes the store to return <c>null</c>, signalling that cleanup may proceed safely.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task StaleManifestCleanupGuard_ExpiredBeyondRecoveryWindow_StoreReturnsNull()
{
var store = new HaTestSessionStore();
// Lease expired hours ago – well beyond any recovery window.
var session = CreateSession("ha-session-3", "pod-a", DateTime.UtcNow.AddHours(-2));
await store.SetAsync(session, TestContext.Current.CancellationToken);
// Controller or cleanup task checks the store before deleting files.
var liveSession = await store.TryGetAsync("ha-session-3", TestContext.Current.CancellationToken);
// Store returns null → cleanup may proceed without risking data loss.
Assert.Null(liveSession);
}
/// <summary>
/// Segment-length selection: when the play-session has an active entry in the store
/// (HA mode is active), the recovery segment length should be preferred over the normal one.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task SegmentLength_UsesRecoveryValue_WhenHaModeIsActive()
{
const int normalSegmentLength = 6;
const int recoverySegmentLength = 2;
var store = new HaTestSessionStore();
var session = CreateSession("ha-session-4", "pod-a", DateTime.UtcNow.AddMinutes(5));
await store.SetAsync(session, TestContext.Current.CancellationToken);
// Simulate the controller's HA-mode check: if the session is in the store, HA mode is active.
var existingSession = await store.TryGetAsync("ha-session-4", TestContext.Current.CancellationToken);
var isHaMode = existingSession is not null;
var effectiveSegmentLength = isHaMode ? recoverySegmentLength : normalSegmentLength;
Assert.True(isHaMode, "Session should be found in the store, activating HA mode.");
Assert.Equal(recoverySegmentLength, effectiveSegmentLength);
}
/// <summary>
/// Segment-length selection: when no entry exists in the store for the play-session
/// (HA mode inactive), the normal segment length should be used.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task SegmentLength_UsesNormalValue_WhenHaModeIsInactive()
{
const int normalSegmentLength = 6;
const int recoverySegmentLength = 2;
var store = new HaTestSessionStore();
// No session registered – HA mode is inactive.
var existingSession = await store.TryGetAsync("nonexistent-session", TestContext.Current.CancellationToken);
var isHaMode = existingSession is not null;
var effectiveSegmentLength = isHaMode ? recoverySegmentLength : normalSegmentLength;
Assert.False(isHaMode, "No session in the store means HA mode should be inactive.");
Assert.Equal(normalSegmentLength, effectiveSegmentLength);
}
/// <summary>
/// Minimal in-memory <see cref="ITranscodeSessionStore"/> used within this test class
/// to avoid a cross-project reference to Jellyfin.MediaEncoding.Tests.
/// </summary>
private sealed class HaTestSessionStore : ITranscodeSessionStore
{
private static readonly TimeSpan LeaseDuration = TimeSpan.FromSeconds(30);
private readonly Dictionary<string, TranscodeSession> _sessions =
new(StringComparer.OrdinalIgnoreCase);
private readonly Lock _lock = new();
public Task<TranscodeSession?> TryGetAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (_sessions.TryGetValue(playSessionId, out var s) && s.LeaseExpiresUtc > DateTime.UtcNow)
{
return Task.FromResult<TranscodeSession?>(Clone(s));
}
return Task.FromResult<TranscodeSession?>(null);
}
}
public Task<bool> TryTakeoverAsync(string playSessionId, string claimingPod, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (!_sessions.TryGetValue(playSessionId, out var s))
{
return Task.FromResult(false);
}
if (s.LeaseExpiresUtc > DateTime.UtcNow)
{
return Task.FromResult(false);
}
s.OwnerPod = claimingPod;
s.LeaseExpiresUtc = DateTime.UtcNow.Add(LeaseDuration);
return Task.FromResult(true);
}
}
public Task SetAsync(TranscodeSession session, CancellationToken cancellationToken = default)
{
lock (_lock)
{
_sessions[session.PlaySessionId] = session;
}
return Task.CompletedTask;
}
public Task RenewLeaseAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (_sessions.TryGetValue(playSessionId, out var s))
{
s.LeaseExpiresUtc = DateTime.UtcNow.Add(LeaseDuration);
}
}
return Task.CompletedTask;
}
public Task DeleteAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
_sessions.Remove(playSessionId);
}
return Task.CompletedTask;
}
public Task<IEnumerable<TranscodeSession>> GetActiveSessionsAsync(CancellationToken cancellationToken = default)
{
lock (_lock)
{
var sessions = _sessions.Values
.Where(s => s.LeaseExpiresUtc > DateTime.UtcNow)
.Select(Clone)
.ToList();
return Task.FromResult<IEnumerable<TranscodeSession>>(sessions);
}
}
public Task SetLiveStreamAsync(LiveStreamSession session, CancellationToken cancellationToken = default)
=> Task.CompletedTask;
public Task<LiveStreamSession?> TryGetLiveStreamAsync(string liveStreamId, string sessionIdOrPlaySessionId, CancellationToken cancellationToken = default)
=> Task.FromResult<LiveStreamSession?>(null);
public Task DeleteLiveStreamAsync(string liveStreamId, string sessionIdOrPlaySessionId, CancellationToken cancellationToken = default)
=> Task.CompletedTask;
private static TranscodeSession Clone(TranscodeSession source)
=> new TranscodeSession
{
PlaySessionId = source.PlaySessionId,
OwnerPod = source.OwnerPod,
LeaseExpiresUtc = source.LeaseExpiresUtc,
ManifestPath = source.ManifestPath,
SegmentPathPrefix = source.SegmentPathPrefix,
MediaSourceId = source.MediaSourceId,
LastCompletedSegmentIndex = source.LastCompletedSegmentIndex,
LastDurablePlaybackOffset = source.LastDurablePlaybackOffset,
};
}
}
}
@@ -0,0 +1,223 @@
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Controller.MediaEncoding;
using Xunit;
namespace Jellyfin.Api.Tests.Controllers
{
/// <summary>
/// Tests for HLS session registration, lease renewal, and cleanup behaviour wired into
/// <see cref="Jellyfin.Api.Controllers.DynamicHlsController"/> in Phase 5.2.2a.
/// These tests verify the <see cref="ITranscodeSessionStore"/> contract used by the controller.
/// </summary>
public class DynamicHlsSessionRegistrationTests
{
private static TranscodeSession CreateSession(string id, string pod)
=> new TranscodeSession
{
PlaySessionId = id,
OwnerPod = pod,
LeaseExpiresUtc = DateTime.UtcNow.AddSeconds(30),
ManifestPath = string.Empty,
SegmentPathPrefix = string.Empty,
MediaSourceId = "media-source-1",
LastCompletedSegmentIndex = 0,
LastDurablePlaybackOffset = 0L,
};
/// <summary>
/// After registering a session via <see cref="ITranscodeSessionStore.SetAsync"/>,
/// <see cref="ITranscodeSessionStore.TryGetAsync"/> must return a non-null result with
/// matching <see cref="TranscodeSession.PlaySessionId"/> and <see cref="TranscodeSession.OwnerPod"/>.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task SessionRegistration_AfterStreamStart_StoreContainsSession()
{
var store = new InMemoryTranscodeSessionStore();
var session = CreateSession("session-reg-1", "pod-a");
await store.SetAsync(session, TestContext.Current.CancellationToken);
var retrieved = await store.TryGetAsync("session-reg-1", TestContext.Current.CancellationToken);
Assert.NotNull(retrieved);
Assert.Equal("session-reg-1", retrieved.PlaySessionId);
Assert.Equal("pod-a", retrieved.OwnerPod);
}
/// <summary>
/// After calling <see cref="ITranscodeSessionStore.DeleteAsync"/>,
/// <see cref="ITranscodeSessionStore.TryGetAsync"/> must return <c>null</c>.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task SessionCleanup_AfterStreamEnd_StoreReturnsNull()
{
var store = new InMemoryTranscodeSessionStore();
var session = CreateSession("session-cleanup-1", "pod-b");
await store.SetAsync(session, TestContext.Current.CancellationToken);
await store.DeleteAsync("session-cleanup-1", TestContext.Current.CancellationToken);
var retrieved = await store.TryGetAsync("session-cleanup-1", TestContext.Current.CancellationToken);
Assert.Null(retrieved);
}
/// <summary>
/// After a session's initial lease window would have expired, calling
/// <see cref="ITranscodeSessionStore.RenewLeaseAsync"/> must extend the lease so that
/// <see cref="ITranscodeSessionStore.TryGetAsync"/> still returns the session as active.
/// </summary>
[Fact]
[Trait("Category", "UnitTest")]
public async Task LeaseRenewal_ExtendsBeyondInitialExpiry()
{
var store = new InMemoryTranscodeSessionStore();
// Create the session with a lease that has already expired.
var session = new TranscodeSession
{
PlaySessionId = "session-renewal-1",
OwnerPod = "pod-c",
LeaseExpiresUtc = DateTime.UtcNow.AddMilliseconds(-1),
ManifestPath = string.Empty,
SegmentPathPrefix = string.Empty,
MediaSourceId = "media-source-1",
LastCompletedSegmentIndex = 0,
LastDurablePlaybackOffset = 0L,
};
await store.SetAsync(session, TestContext.Current.CancellationToken);
// Verify the session is not accessible because the lease has expired.
Assert.Null(await store.TryGetAsync("session-renewal-1", TestContext.Current.CancellationToken));
// Renew the lease.
await store.RenewLeaseAsync("session-renewal-1", TestContext.Current.CancellationToken);
// After renewal the session must be accessible again.
var renewed = await store.TryGetAsync("session-renewal-1", TestContext.Current.CancellationToken);
Assert.NotNull(renewed);
Assert.Equal("session-renewal-1", renewed.PlaySessionId);
Assert.True(renewed.LeaseExpiresUtc > DateTime.UtcNow);
}
/// <summary>
/// Minimal thread-safe in-memory implementation of <see cref="ITranscodeSessionStore"/>
/// used within this test class to avoid a cross-project reference.
/// </summary>
private sealed class InMemoryTranscodeSessionStore : ITranscodeSessionStore
{
private static readonly TimeSpan DefaultLeaseDuration = TimeSpan.FromSeconds(30);
private readonly Dictionary<string, TranscodeSession> _sessions =
new(StringComparer.OrdinalIgnoreCase);
private readonly Lock _lock = new();
public Task<TranscodeSession?> TryGetAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (_sessions.TryGetValue(playSessionId, out var session) && session.LeaseExpiresUtc > DateTime.UtcNow)
{
return Task.FromResult<TranscodeSession?>(Clone(session));
}
return Task.FromResult<TranscodeSession?>(null);
}
}
public Task<bool> TryTakeoverAsync(string playSessionId, string claimingPod, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (!_sessions.TryGetValue(playSessionId, out var session))
{
return Task.FromResult(false);
}
if (session.LeaseExpiresUtc > DateTime.UtcNow)
{
return Task.FromResult(false);
}
session.OwnerPod = claimingPod;
session.LeaseExpiresUtc = DateTime.UtcNow.Add(DefaultLeaseDuration);
return Task.FromResult(true);
}
}
public Task SetAsync(TranscodeSession session, CancellationToken cancellationToken = default)
{
lock (_lock)
{
_sessions[session.PlaySessionId] = session;
}
return Task.CompletedTask;
}
public Task RenewLeaseAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
if (_sessions.TryGetValue(playSessionId, out var session))
{
session.LeaseExpiresUtc = DateTime.UtcNow.Add(DefaultLeaseDuration);
}
}
return Task.CompletedTask;
}
public Task DeleteAsync(string playSessionId, CancellationToken cancellationToken = default)
{
lock (_lock)
{
_sessions.Remove(playSessionId);
}
return Task.CompletedTask;
}
public Task<IEnumerable<TranscodeSession>> GetActiveSessionsAsync(CancellationToken cancellationToken = default)
{
lock (_lock)
{
var sessions = _sessions.Values
.Where(s => s.LeaseExpiresUtc > DateTime.UtcNow)
.Select(Clone)
.ToList();
return Task.FromResult<IEnumerable<TranscodeSession>>(sessions);
}
}
public Task SetLiveStreamAsync(LiveStreamSession session, CancellationToken cancellationToken = default)
=> Task.CompletedTask;
public Task<LiveStreamSession?> TryGetLiveStreamAsync(string liveStreamId, string sessionIdOrPlaySessionId, CancellationToken cancellationToken = default)
=> Task.FromResult<LiveStreamSession?>(null);
public Task DeleteLiveStreamAsync(string liveStreamId, string sessionIdOrPlaySessionId, CancellationToken cancellationToken = default)
=> Task.CompletedTask;
private static TranscodeSession Clone(TranscodeSession source)
=> new TranscodeSession
{
PlaySessionId = source.PlaySessionId,
OwnerPod = source.OwnerPod,
LeaseExpiresUtc = source.LeaseExpiresUtc,
ManifestPath = source.ManifestPath,
SegmentPathPrefix = source.SegmentPathPrefix,
MediaSourceId = source.MediaSourceId,
LastCompletedSegmentIndex = source.LastCompletedSegmentIndex,
LastDurablePlaybackOffset = source.LastDurablePlaybackOffset,
};
}
}
}