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🌊 Reverse Proxy (Streaming, Caching & Rate Limits)

This section documents the reverse_proxy: block inside config.yml. It is the most critical block for determining runtime behavior when Tuliprox actively proxies video streams to clients (Reverse Proxy Mode), rather than just redirecting them.

It manages how Tuliprox establishes upstream connections, buffers video frames, handles sudden client disconnects, and caches static resources like EPG images and channel logos.

It also contains the optional telemetry pipeline for stream reliability analysis:

  • stream_history stores raw stream lifecycle events on disk.
  • qos_aggregation periodically condenses those raw events into compact QoS snapshots.
  • The Web UI can then inspect both the raw history view and the aggregated QoS summaries.

Read This First: Connection Handling Handbook

The reverse_proxy.stream block now interacts with a broader connection-handling model:

  • user limits
  • soft connections
  • priorities
  • admission strategies
  • grace periods
  • HLS and catchup sessions
  • shared streams
  • provider-side preemption

If you want to understand why a stream starts, waits, gets reused, gets preempted, or is rejected, read these pages first:

Top-level entries

reverse_proxy:
  resource_rewrite_disabled: false
  rewrite_secret: A1B2C3D4E5F60718293A4B5C6D7E8F90
  stream:
  cache:
  hls_cache:
  rate_limit:
  disabled_header:
  resource_retry:
  geoip:
  stream_history:
  qos_aggregation:

Note: Reverse Proxy mode can be activated for each user individually.

General Parameters

Parameter Type Default Technical Impact & Background
resource_rewrite_disabled Bool false Normally, Tuliprox rewrites all image URLs in playlists to point to itself (e.g., http://tuliprox:8901/resource/...). If set to true, original URLs are kept (clients load images directly from the provider). Warning: Local caching will stop working if this is enabled!
rewrite_secret String "" A 32-character Hex string (16 bytes). Tuliprox encrypts/signs the original image URLs during the rewrite process. To prevent image URLs from becoming invalid after a server restart, you MUST enter a static secret here.
stream_history Block null Optional stream telemetry block that persists raw connect/disconnect/startup-failure events to daily history files.
qos_aggregation Block null Optional background worker that aggregates stream history into compact per-stream QoS snapshots.

Note: You can generate a random secret using:

openssl rand -hex 16
# or
node -e "console.log(require('crypto').randomBytes(16).toString('hex').toUpperCase())"

1. Stream Management (stream)

This sub-block defines how Tuliprox maintains stream stability, buffers data, and handles HLS/Catchup session affinity.

Admission strategies in this block can optionally evict an existing stream after normal and soft user admission are already exhausted:

  • evict_user_same_ip_oldest
  • evict_user_same_ip_latest
  • evict_user_oldest
  • evict_user_latest
  • grace_instant_stream
  • grace_hold_stream

Order matters.

If you want same-IP eviction to be preferred, place the same-IP rule before the broader user-wide rule with the same oldest/latest policy.

Examples:

  • valid: evict_user_same_ip_oldest, then evict_user_oldest
  • invalid: evict_user_oldest, then evict_user_same_ip_oldest
  • valid: evict_user_same_ip_latest, then evict_user_latest
  • invalid: evict_user_latest, then evict_user_same_ip_latest
reverse_proxy:
  stream:
    retry: true
    buffer:
      enabled: true
      size: 1024
    throttle_kbps: 12500
    grace_period_millis: 2000
    grace_period_timeout_secs: 4
    grace_period_hold_stream: true
    hls_session_ttl_secs: 15
    catchup_session_ttl_secs: 45
    shared_burst_buffer_mb: 12
    metrics_enabled: false

Stream Parameters in Detail

Parameter Type Default Technical Impact & Background
retry Bool true Retries connecting to the upstream provider during the initial stream open when the provider returns a transient failure or no usable stream. Once a stream has started, Tuliprox does not transparently replace that live upstream inside the same client response.
buffer.enabled Bool false Enables an asynchronous ring-buffer in RAM between the provider download stream and the client upload stream. Necessary if the provider stream is faster than the consumer can process.
buffer.size Int 0 The size of the buffer in Chunks (1 Chunk = 8192 Bytes). A value of 1024 equals approximately 8 Megabytes of RAM per active stream.
throttle_kbps Int 0 Background: Some players download VODs (Movies) at maximum line speed ("Bursting"). Providers often view this as abuse or scraping and will ban the IP. By throttling (e.g., to 12500 kbps), you force the download into a constant, inconspicuous flow. Supports units like KB/s, MB/s, kbps, Mibps.
metrics_enabled Bool false Monitoring: If active, Tuliprox samples the live bandwidth (in kbps) and transferred bytes for every active reverse-proxied stream and pushes them via WebSockets to the Web UI. It adds a tiny bit of CPU overhead but is invaluable for debugging buffering issues.
grace_period_millis Int 2000 The exact time window in ms where a temporary over-allocation is allowed (see notes on The VLC Seek Problem for details).
grace_period_timeout_secs Int 4 A hard timeout limit for overlapping "ghost sessions" to expire.
grace_period_hold_stream Bool true Tuliprox artificially holds back video data to the client, waiting for grace check to finish, so it doesn't trigger provider prematurely.
hls_session_ttl_secs Int 15 Keeps virtual provider slot open between HLS segment (.ts) requests to prevent provider bans for "Account Hopping".
catchup_session_ttl_secs Int 45 Same session-holding principle applied to Archive/Catchup TV. See notes on section Session TTLs for HLS & Catchup for details.
shared_burst_buffer_mb Int 12 Minimum burst buffer size (in MB) used for shared live streams to immediately synchronize new clients without Keyframe dropouts. See notes on section Shared Live Streams for details.

1.1 retry & buffer (Deep Dive)

Tuliprox handles streams differently based on these settings:

  • Option A: Both retry: false and buffer.enabled: false ➔ The provider stream is piped directly to the client with
    minimal overhead.
  • Option B: retry: true retries transient failures while opening the provider stream. buffer.enabled: true adds
    buffered streaming with a higher memory footprint.

Stream-type provider behavior:

  • Plain TS live is socket/request-oriented. A new TS reconnect is a new provider allocation and may use another provider account if the selected account is unavailable.
  • Initial stream-open retries may also rotate configured provider URLs/accounts when failover is enabled.
  • HLS, DASH, VOD, series, and catchup are provider-affine after a session exists. Follow-up segment, seek, range, or
    reopen requests must stay on the provider account pinned in that session; if that account is unavailable, Tuliprox
    fails the follow-up instead of silently migrating it.
  • retry: false disables stream-open retry/failover for stream requests.

Ring-Buffer Calculation

buffer.size is defined in chunks of 8192 bytes (8 KB).

  • A size of 1024 equals approx. 8 MB of RAM per active stream.
  • Shared Streams Impact: If share_live_streams.mpeg_ts is enabled, each channel consumes at least 12 MB regardless of client count. Increasing size above 1024 (e.g., 2048) increases this to 24 MB per shared channel.

1.2 throttle_kbps

Prevents provider bans by limiting "bursting" players. Supported units: KB/s, MB/s, KiB/s, MiB/s, kbps, mbps, Mibps.

Reference Table for Throttling:

Resolution Framerate Bitrate (kbps) Quality
480p (854x480) 30 fps 819 – 2,457 Low-Quality
720p (1280x720) 30 fps 2,457 – 5,737 HD-Streams
1080p (1920x1080) 30 fps 5,737 – 12,288 Full-HD
4K (3840x2160) 30 fps 20,480 – 49,152 Ultra-HD

1.3 grace_period (The VLC Seek Problem)

If max_connections is > 0, seeking can trigger a 509/401 error because the old connection isn't closed yet.

  • grace_period_millis (Default: 2000): Grants a temporary over-allocation during switchover.
  • grace_period_timeout_secs (Default: 4): How long a grace grant lasts before a new one can be made.
  • grace_period_hold_stream: If true, Tuliprox waits for the check to complete before sending data, preventing player timeouts on "exhausted" switches.

1.4 HLS & Catchup Session TTLs

HLS/Catchup clients connect and disconnect repeatedly. Tuliprox uses a Virtual Reservation to maintain account affinity:

  • HLS (15s): The real provider slot is only held during active requests. The reservation keeps the provider account stable between segment fetches.
  • Catchup (45s): Keeps the reservation alive during seeking and reconnects.
  • Note: Channel switches from the same client immediately take over the reservation, bypassing the TTL.

Important boundary:

  • These TTLs are for HLS/catchup style session continuity.
  • Regular TS/VOD/local playback is socket-bound for admission and user-connection counting.
  • Opening the same TS/VOD stream on a second socket consumes another connection or soft slot.

2. Resource Caching (cache)

Tuliprox maintains a local disk cache for channel logos, posters, and EPG images. This reduces the load on provider servers and significantly speeds up playlist loading times for your clients.

reverse_proxy:
  cache:
    enabled: true
    size: 1GB
    directory: ./cache

Cache Parameter Details

Parameter Type Default Technical Impact
enabled Bool false Global switch for resource caching. Note: Requires resource_rewrite_disabled: false.
size Size 1GB Maximum disk space allocation. Supported units: KB, MB, GB, TB.
directory String ./cache Storage location. Relative paths are resolved against the storage_dir.

Technical Background

  • LRU Logic: Operates as a Least Recently Used cache. When the size limit is reached, Tuliprox automatically evicts the oldest/least accessed images to make room for new content.
  • Encryption: Cached resources are indexed using a hash derived from the rewrite_secret. If the secret changes, the old cache becomes orphaned.
  • Client Delivery: Instead of the client downloading directly from the provider, Tuliprox serves the local file, acting as a high-speed CDN for your media metadata.

2.1 HLS Cache (hls_cache)

This block configures the Live HLS cache proxy. It only defines operating parameters. For an operator-friendly explanation, start with Shared HLS Sessions. For the configuration reference, see Shared HLS Configuration. For the shared session, access lease, and transient delivery state machines, see HLS Cache State Machines.

reverse_proxy:
  hls_cache:
    cache_path: "/tmp/tuliprox/cache/hls"
    strip:
      mode: "segments"
      value: 0
    cache_duration: 300
    cache_bytes: "10GB"
    cache_bytes_per_session: "512MB"
    max_segments_prefetch: 6
    max_concurrent_segment_fetches_per_session: 2
    max_concurrent_segment_fetches_global: 64
    origin_manifest_timeout_ms: 3000
    origin_segment_timeout_ms: 10000
    session_idle_timeout: 300
    segment_repair:
      max_level: "off"
      apply_to_first_segments: 1
      max_parallel_repairs: 1
      postprocess_timeout_ms: 2000
      corrupt_segment_watchdog:
        mode: "off"
        max_parallel_jobs: 1

HLS Cache Parameter Details

Parameter Type Default Technical Impact
cache_path Path /tmp/tuliprox/cache/hls Root directory for future HLS segment and MAP cache objects.
strip.mode String segments Interprets strip.value as either a segment count (segments) or accumulated #EXTINF duration (seconds).
strip.value Int 0 Initial tail holdback for the first rendered HLS view.
cache_duration Seconds 300 Retention baseline for unprotected HLS cache objects.
cache_bytes Byte size 10GB Global HLS cache byte budget.
cache_bytes_per_session Byte size 512MB Per-session HLS cache byte budget.
max_segments_prefetch Int 6 Maximum session-local segment prefetch queue depth.
max_concurrent_segment_fetches_per_session Int 2 Maximum concurrent future segment fetches for one HLS session.
max_concurrent_segment_fetches_global Int 64 Maximum concurrent future segment fetches across all HLS sessions.
origin_manifest_timeout_ms Milliseconds 3000 Timeout for future Origin manifest fetches.
origin_segment_timeout_ms Milliseconds 10000 Timeout for future Origin segment fetches.
session_idle_timeout Seconds 300 Idle timeout before a future HLS cache session may be collected.
segment_repair.max_level String off Maximum repair level allowed by the codec-aware MPEG-TS segment repair policy (off, low, medium, high).
segment_repair.apply_to_first_segments Int 1 Number of visible TS objects checked per access-lease activation.
segment_repair.max_parallel_repairs Int 1 Maximum concurrent repair jobs. Must not exceed max_segments_prefetch when repair is enabled.
segment_repair.postprocess_timeout_ms Milliseconds 2000 Shared timeout for the complete segment post-processing chain, including repair and watchdog work.
segment_repair.corrupt_segment_watchdog.mode String off Optional watchdog for residual TS packet-corrupt warnings after regular repair (off, detect_only, sanitize, diagnostic).
segment_repair.corrupt_segment_watchdog.max_parallel_jobs Int 1 Maximum concurrent watchdog sanitize jobs.

Supported byte-size units:

  • B
  • KB, MB, GB, TB as decimal 1000-based units
  • KiB, MiB, GiB, TiB as binary 1024-based units
  • no suffix means bytes

Important boundaries:

  • reverse_proxy.hls_cache only prepares the global cache engine. A target must also set options.share_live_streams.hls: true in source.yml before generated HLS live entries use the shared HLS path.
  • HLS cache retry behavior is fixed internally and is not user-configurable.
  • reverse_proxy.rewrite_secret must stay stable. It is used for future HLS proxy_session_id values and transient resource IDs.
  • session_idle_timeout controls HLS cache access-lease validity and idle cleanup. It is independent from reverse_proxy.stream.hls_session_ttl_secs, which belongs to the non-cache HLS request continuity path.
  • This block does not enable legacy resource caching; image/logo/EPG caching remains controlled by reverse_proxy.cache.

3. Rate Limiting (rate_limit)

This block implements an IP-based Token-Bucket rate limiter. It protects your Tuliprox instance and upstream providers from DDoS attacks, malfunctioning scrapers, or aggressive players by restricting the frequency of incoming HTTP requests.

reverse_proxy:
  rate_limit:
    enabled: true
    period_millis: 500
    burst_size: 10

Rate Limit Parameter Details

Parameter Type Default Technical Impact
enabled Bool false Global switch for the rate limiting engine.
period_millis Int 500 The refill rate. Defines how many milliseconds it takes to replenish exactly one request token.
burst_size Int 10 The bucket capacity. Allows a client to send this many requests instantly before the rate limit kicks in.

Technical Background

  • Mechanism: A client starts with a full "bucket" of burst_size tokens. Every request consumes one token. Once empty, the client must wait period_millis for a new token to be generated.
  • IP-Detection: Tuliprox identifies clients by their IP address. If you are running Tuliprox behind a proxy (Nginx, Traefik), ensure headers like X-Forwarded-For or X-Real-IP are passed correctly.
  • Behavior: When a client exceeds the limit, Tuliprox returns an HTTP 429 (Too Many Requests) status, protecting your CPU and provider bandwidth.

This block controls which HTTP headers Tuliprox removes before forwarding a client request to the upstream provider. Stripping these headers is essential to prevent the provider from detecting proxy usage, internal IP addresses, or specific player fingerprints.

reverse_proxy:
  disabled_header:
    referer_header: true    # Removes 'Referer' (prevents leaking your Tuliprox URL/Domain)
    x_header: true          # Removes all 'X-*' headers (e.g., X-Forwarded-For, X-Real-IP)
    cloudflare_header: true # Removes 'CF-*' headers (hides Cloudflare origin details)
    custom_header:          # List of additional specific headers to be dropped
      - "X-Powered-By"
      - "my-custom-tracker"

Header Stripping Parameter Details

Parameter Type Default Technical Impact
referer_header Bool false Suppresses the source of the request. Prevents your Tuliprox instance from being logged at the provider.
x_header Bool false Critical: Wildcard-strips all headers starting with X-. These are the most common indicators used for proxy detection.
cloudflare_header Bool false Removes Cloudflare-specific headers. Essential if Tuliprox itself is running behind a Cloudflare proxy.
custom_header List [] Manual blacklist for headers not covered by the automatic toggles above (e.g., vendor-specific trackers).

Security Note: Many providers analyze headers for "restreaming" patterns. Combining x_header: true with a neutral user_agent in your source.yml provides the best protection against account flags.

5. Resource Retries (resource_retry)

This block defines the retry behavior when Tuliprox proxies static resources (logos, EPG images). It ensures transient network issues or temporary provider timeouts don't result in broken images for your clients.

reverse_proxy:
  resource_retry:
    max_attempts: 3
    backoff_millis: 250
    backoff_multiplier: 1.5
    failover_redirect_patterns:
      - "service-abuse"

Resource Retry Parameter Details

Parameter Type Default Technical Impact
max_attempts Int (u8) 3 Maximum number of download tries before giving up. Minimum is 1.
backoff_millis Duration 250 Initial wait time (ms) after the first failure.
backoff_multiplier Float 1.5 Factor by which the delay grows. > 1.0 creates an exponential backoff.
failover_redirect_patterns List [] Regex patterns to identify "Abuse" or "Blocked" redirect URLs from providers.

Technical Background

  • Exponential Backoff: The wait time for each attempt is calculated as: $$ \text{delay} = \text{backoff_millis} \times (\text{backoff_multiplier}^{\text{attempt}-1}) $$
  • Failover Logic: Providers sometimes redirect blocked requests (HTTP 302) to a "service-abuse.png" image. If a redirect URL matches a pattern in failover_redirect_patterns, Tuliprox treats it as a hard failure and triggers a retry instead of serving the abuse image.
  • Smart Handling: If an upstream server sends a Retry-After header, Tuliprox prioritizes that value over the local backoff calculation.

6. GeoIP Resolution (geoip)

This block enables local IP-to-Country mapping. It allows the Tuliprox Web UI to display country flags in the "Active Streams" tab, providing immediate visual feedback on client locations.

reverse_proxy:
  geoip:
    enabled: true
    url: "https://raw.githubusercontent.com/sapics/ip-location-db/refs/heads/main/asn-country/asn-country-ipv4.csv"

GeoIP Parameter Details

Parameter Type Default Technical Impact
enabled Bool false Global switch for GeoIP resolution.
url String (Optional) Source URL for the GeoIP CSV database.

Technical Background

  • Data Format: Tuliprox requires a CSV format with exactly three columns: range_start, range_end, country_code Example: 1.0.0.0, 1.0.0.255, AU
  • Performance: The database is loaded into a high-speed memory-mapped structure to ensure that resolving client locations adds zero latency to stream processing.
  • Automation: To keep the data accurate, use the GeoIpUpdate task type within the schedules block. This periodically downloads and rebuilds the local binary lookup file.
  • Privacy: All resolution happens locally on your server; no client IPs are ever sent to external third-party APIs for location lookups.

The CSV file must have exactly 3 columns: range_start,range_end,country_code. (The DB is periodically updated via the schedules block using the GeoIpUpdate task type).

7. Stream History (stream_history)

This block enables persistent stream lifecycle telemetry. Tuliprox writes daily binary history files containing successful connects, startup failures, disconnect reasons, provider-open failures, reconnect counts, latency signals, and stable stream identity fields.

When the same channel exists multiple times across different providers, stream history gives Tuliprox the raw event-level view for each variant. It records which variant failed, how it failed, how often it reconnects, and whether the problem happened during startup or while streaming.

User impact:

  • Gives you a reliable answer to questions like "Which stream failed?", "Was this a provider abort or a capacity problem?",
    and "How often does this stream reconnect?"
  • Builds the raw data foundation for later QoS analysis and failover optimization.
  • Adds asynchronous background disk writes, but does not put synchronous work into the live streaming hotpath.
reverse_proxy:
  stream_history:
    stream_history_enabled: true
    stream_history_batch_size: 128
    stream_history_retention_days: 30
    stream_history_directory: ./stream_history

Stream History Parameters

Parameter Type Default Technical Impact
stream_history_enabled Bool false Master switch for stream telemetry. If disabled, no stream history files are written.
stream_history_batch_size Int 128 Number of records buffered before the writer flushes a block to disk. Higher values reduce write frequency; lower values make new records visible sooner.
stream_history_retention_days Int 14 Number of UTC day partitions retained before old history files are deleted.
stream_history_directory String stream_history under storage_dir Directory for daily stream history files. Relative paths are resolved against storage_dir.

Technical Background

  • Stream history records are written asynchronously in append-friendly daily files.
  • Recorded event types include:
    • successful connect
    • startup failure (connect_failed)
    • disconnect
  • Recorded QoS metadata includes:
    • disconnect reason
    • startup failure reason
    • failure stage
    • provider error class / HTTP status
    • reconnect counts
    • first-byte latency
    • stream identity fields for later aggregation

8. QoS Aggregation (qos_aggregation)

This block enables the periodic QoS aggregation worker. It reads stream history in the background and builds compact per-stream QoS snapshots that summarize recent reliability.

In practice, QoS turns raw stream history into a compact health view for each channel variant. This makes it possible to compare equivalent variants of the same channel across providers, rank them by reliability, and use that information for channel selection and failover decisions.

User impact:

  • Lets you see a condensed reliability view without manually scanning raw history files.
  • Prepares the data that the later failover feature can use to prioritize the most reliable stream/provider candidates.
  • Keeps heavy analysis work out of request handling and out of the streaming hotpath.
reverse_proxy:
  stream_history:
    stream_history_enabled: true
  qos_aggregation:
    enabled: true
    interval_secs: 300

QoS Aggregation Parameters

Parameter Type Default Technical Impact
enabled Bool false Enables the background QoS worker. Only effective if stream_history.stream_history_enabled is also true.
interval_secs Int 300 Polling interval for the aggregation loop. Lower values update snapshots faster but increase background disk and CPU work.

Technical Background

  • The worker reads raw stream history by UTC day and stores snapshots in dedicated B+Tree databases.
  • Snapshots are keyed by stable stream identity and contain rolling 24h, 7d, and 30d windows.
  • QoS data is persisted locally, so it survives restarts and can later be consumed by the failover feature without rescanning all history every time.
  • If stream history is disabled, QoS aggregation is automatically disabled during config preparation.

 

Additional Information

Session TTLs for HLS (.m3u8) & Catchup

HLS streams do not consist of an endless TCP pipe. Instead, the player downloads small .ts segments every few seconds (e.g., seg1.ts, seg2.ts).

If Tuliprox released and re-acquired the provider slot for every single segment, providers would block the account for "Account Hopping" or spam. Tuliprox simulates a continuous session:

  • hls_session_ttl_secs: 15: After a .ts segment finishes downloading, the physical slot to the provider is closed, but the "Virtual Slot" for this specific user remains reserved for 15 seconds. No other user can steal this slot during this window. Channel switches from the same client can immediately take over the reservation.
  • The same principle applies to Archive/Catchup TV (catchup_session_ttl_secs: 45), which shares the same fragmentation and seeking issues.

Archive Proxy Behavior & Live Playback Invariant

When Tuliprox operates as a reverse proxy, it can securely proxy upstream archive/catchup requests.

  • Live Playback Invariant: A standard live stream request (e.g., /m3u-stream/live/user/password/1234.m3u8) always starts
    current live playback. Normal live requests never activate archive mode, even if arbitrary query parameters are added by the player.
  • Archive mode is only activated through a dedicated catchup endpoint (such as the generated Tuliprox catchup URLs) or a signed marker
    generated by Tuliprox itself.
  • Live and archive requests are completely isolated and never share the same session key.

Shared Live Streams

Tuliprox can share a live stream (share_live_streams.mpeg_ts: true in the target options of source.yml). If 5 users watch the same Live-TV channel, Tuliprox pulls the stream only 1x from the provider and multicasts the bytes locally to 5 clients.

To ensure a user who tunes in 10 seconds later doesn't get player errors due to missing I-Frames/Keyframes, Tuliprox continuously keeps the last X Megabytes (shared_burst_buffer_mb, default 12) in RAM. It fires this burst buffer at new subscribers so their decoders can instantly synchronize.

The "VLC Seek Problem" & Grace Periods

When a user fast-forwards or rewinds a VOD, the player calculates the new byte offset, drops the old TCP connection, and immediately fires a new HTTP GET request (with a Range header) to Tuliprox.

The Problem: It takes milliseconds to seconds for the upstream provider to realize the old connection is dead. If you have a max_connections: 1 limit at the provider, they will view this new seek-request as a second concurrent stream and reject it with an HTTP 509 (Bandwidth Exceeded) or HTTP 401 error.

The Tuliprox Solution:

  • grace_period_millis: 2000: Tuliprox grants the user a temporary over-allocation (Grace) for exactly this duration.
  • grace_period_hold_stream: true: Tuliprox artificially holds back the video data to the client, waiting for the grace check to finish, so it doesn't trigger the provider prematurely.
  • After the milliseconds expire, Tuliprox checks internally: Is the old connection truly gone now?
    If Yes ➔ Data flows.
    If No ➔ The new connection is hard-killed (serving the user_connections_exhausted.ts video) because the user is actually illegally watching twice.
  • grace_period_timeout_secs: 4: A hard timeout limit for overlapping "ghost sessions" to expire.