facontidavide · Sep 20, 2026 · Sep 20, 2026 · Sep 20, 2026 · Sep 20, 2026 · Sep 20, 2026
diff --git a/.github/workflows/release-debs.yaml b/.github/workflows/release-debs.yaml
@@ -27,6 +27,10 @@ jobs:
             os_codename: noble
             container: rostooling/setup-ros-docker:ubuntu-noble-ros-kilted-ros-base-latest
             runner: ubuntu-24.04
+          - ros_distro: lyrical
+            os_codename: resolute
+            container: rostooling/setup-ros-docker:ubuntu-resolute-ros-lyrical-ros-base-latest
+            runner: ubuntu-24.04
 
     runs-on: ${{ matrix.runner }}
     container:
@@ -49,9 +53,9 @@ jobs:
       - name: Install IXWebSocket from source
         run: |
           cd /tmp
-          wget -q https://github.com/machinezone/IXWebSocket/archive/refs/tags/v11.4.6.tar.gz
-          tar xzf v11.4.6.tar.gz
-          cd IXWebSocket-11.4.6
+          wget -q https://github.com/machinezone/IXWebSocket/archive/refs/tags/v12.0.1.tar.gz
+          tar xzf v12.0.1.tar.gz
+          cd IXWebSocket-12.0.1
           cmake -B build -DCMAKE_BUILD_TYPE=Release -DUSE_TLS=OFF -DUSE_ZLIB=ON
           cmake --build build -j$(nproc)
           cmake --install build

diff --git a/.github/workflows/ros_lyrical.yaml b/.github/workflows/ros_lyrical.yaml
@@ -0,0 +1,20 @@
+name: "ROS: Lyrical"
+
+on:
+  push:
+    branches: [development, main]
+  pull_request:
+    branches: [development, main]
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build-and-test:
+    uses: ./.github/workflows/_ros.yaml
+    with:
+      ros_distro: lyrical
+      container: rostooling/setup-ros-docker:ubuntu-resolute-ros-lyrical-ros-base-latest
+      runner: ubuntu-24.04
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -2,6 +2,23 @@
 Changelog for package pj_ros_bridge
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+Forthcoming
+-----------
+* WebSocket permessage-deflate declined server-side (redundant with our own
+  ZSTD compression; was costing CPU for no bandwidth benefit).
+* ROS2: ingest executor polled and drained (``ingest_poll_interval_ms``,
+  default 5 ms) instead of blocking ``spin()``, amortizing the per-wait-cycle
+  wait-set rebuild; publish/request/timeout timers moved to their own
+  executor thread so a long publish cycle never delays ingest.
+* ROS2: ``min_qos_depth`` default raised ``1`` -> ``10`` so the ingest poll
+  interval can't overflow a shallow reader between polls.
+* Dependencies: IXWebSocket 11.4.6 -> 12.0.1 (FetchContent and .deb builds),
+  Fast DDS 3.4.0 -> 3.4.3, CLI11 2.6.0 -> 2.6.2. Fixed the FastDDS/RTI
+  link failure when IXWebSocket is fetched with TLS.
+* CI and Debian release for ROS 2 Lyrical.
+* Removed zero-initializing copies in the ingest and serializer hot paths
+  (``resize()`` + ``memcpy`` -> direct-construct/``insert``).
+
 0.9.0 (2026-07-11)
 ------------------
 * Size-class frames: isolate heavy messages (``>= heavy_frame_threshold_bytes``)

diff --git a/CLAUDE.md b/CLAUDE.md
@@ -51,7 +51,7 @@ make -j$(nproc)
 - **CLI11** — FetchContent (RTI backend only)
 
 ### FastDDS Backend (Conan-managed)
-- **eProsima Fast DDS 3.4.0** — via Conan (`fast-dds/3.4.0`)
+- **eProsima Fast DDS 3.4.3** — via Conan (`fast-dds/3.4.3`)
 - **eProsima Fast CDR 2.x** — transitive dependency via Conan
 - **CLI11** — FetchContent (for CLI parsing, shared with RTI)
 
@@ -105,7 +105,7 @@ make -j$(nproc)
 ### Event Loop
 
 BridgeServer does NOT own timers. The entry point (`main.cpp`) drives the event loop:
-- **ROS2**: `rclcpp` wall timers call `process_requests()`, `publish_aggregated_messages()`, `check_session_timeouts()`
+- **ROS2**: `rclcpp` wall timers (`process_requests()`, `publish_aggregated_messages()`, `check_session_timeouts()`) run on their own dedicated executor thread, so a long publish/zstd cycle never delays ingest. The ingest executor itself is polled (`ingest_poll_interval_ms`, default 5 ms) via `spin_some()` instead of blocking in `spin()`; subscription callbacks drain their DDS reader on each poll.
 - **RTI**: `std::chrono` loop with `std::this_thread::sleep_for()`
 - **FastDDS**: `std::chrono` loop with `std::this_thread::sleep_for()` (same pattern as RTI)
 
@@ -191,7 +191,7 @@ Then, for each message in the (compressed) payload:
 - CLI11 (FetchContent, for CLI parsing)
 
 ### FastDDS Backend
-- eProsima Fast DDS 3.4.0 (Conan: `fast-dds/3.4.0`)
+- eProsima Fast DDS 3.4.3 (Conan: `fast-dds/3.4.3`)
 - eProsima Fast CDR 2.x (transitive Conan dependency)
 - CLI11 (FetchContent, for CLI parsing)
 
@@ -234,8 +234,9 @@ publish_rate: 50.0             # Hz
 session_timeout: 10.0          # seconds
 strip_large_messages: false    # Opt-in: strip Image/PointCloud2/etc data fields
 topic_whitelist: [".*"]        # Full-match regex patterns restricting visible/subscribable topics
-min_qos_depth: 1               # Minimum KEEP_LAST subscription depth after aggregating publisher depths
+min_qos_depth: 10              # Minimum KEEP_LAST subscription depth after aggregating publisher depths
 max_qos_depth: 100             # Maximum KEEP_LAST subscription depth after aggregating publisher depths
+ingest_poll_interval_ms: 5.0   # Ingest executor poll interval (drains subscriptions each poll); 0 = blocking spin
 topic_poll_interval: 1.0       # Seconds between topics_changed notification polls; 0 disables polling
 client_backlog_size: 100       # Max frames queued per slow client before dropping the oldest (must be > 0)
 heavy_frame_threshold_bytes: 262144  # Isolate messages >= this size into their own size-class frame; 0 disables

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -69,8 +69,8 @@ if(NOT ixwebsocket_FOUND)
   message(STATUS "IXWebSocket not found — fetching via FetchContent")
   FetchContent_Declare(
     ixwebsocket
-    URL https://github.com/machinezone/IXWebSocket/archive/refs/tags/v11.4.6.tar.gz
-    URL_HASH SHA256=c024334f8e45980836c67008979a884d6dcc5ef067dd2eb1fa7241f4c17ddc32
+    URL https://github.com/machinezone/IXWebSocket/archive/refs/tags/v12.0.1.tar.gz
+    URL_HASH SHA256=d23bdc91dbfe2b9ae13c322d539392d7a6b8b506560f41c90e227fa0f86a2405
   )
   set(USE_TLS ${PJ_BRIDGE_TLS} CACHE BOOL "" FORCE)
   if(PJ_BRIDGE_TLS)
@@ -79,6 +79,11 @@ if(NOT ixwebsocket_FOUND)
   set(USE_ZLIB ON CACHE BOOL "" FORCE)
   set(IXWEBSOCKET_INSTALL OFF CACHE BOOL "" FORCE)
   FetchContent_MakeAvailable(ixwebsocket)
+  if(PJ_BRIDGE_TLS)
+    # The static library does not export its OpenSSL dependency to consumers.
+    find_package(OpenSSL REQUIRED)
+    target_link_libraries(ixwebsocket INTERFACE OpenSSL::SSL OpenSSL::Crypto)
+  endif()
 else()
   message(STATUS "Using system IXWebSocket")
 endif()
@@ -149,11 +154,12 @@ if(ament_cmake_FOUND)
     pj_bridge_app
   )
 
-  ament_target_dependencies(pj_bridge_ros2_lib PUBLIC
-    ament_index_cpp
-    rclcpp
-    sensor_msgs
-    nav_msgs
+  # target_link_libraries, not ament_target_dependencies: removed in newer distros (Lyrical)
+  target_link_libraries(pj_bridge_ros2_lib PUBLIC
+    ament_index_cpp::ament_index_cpp
+    rclcpp::rclcpp
+    ${sensor_msgs_TARGETS}
+    ${nav_msgs_TARGETS}
   )
 
   # ROS2 executable
@@ -165,10 +171,6 @@ if(ament_cmake_FOUND)
     pj_bridge_ros2_lib
   )
 
-  ament_target_dependencies(pj_bridge_ros2
-    rclcpp
-  )
-
   # Install ROS2 executable
   install(TARGETS pj_bridge_ros2
     DESTINATION lib/${PROJECT_NAME}
@@ -276,12 +278,6 @@ if(BUILD_TESTING AND ament_cmake_FOUND)
     data_path
   )
 
-  ament_target_dependencies(${PROJECT_NAME}_tests
-    rclcpp
-    sensor_msgs
-    nav_msgs
-  )
-
   # Sanitizer environment settings for CTest
   if(ENABLE_TSAN)
     set_tests_properties(${PROJECT_NAME}_tests PROPERTIES

diff --git a/README.md b/README.md
@@ -4,7 +4,7 @@
 
 A high-performance bridge server that forwards middleware topic content over WebSocket to PlotJuggler clients. Three backends share a common core:
 
-- **ROS2** (`pj_bridge_ros2`) — ROS2 Humble / Jazzy / Kilted via `rclcpp`
+- **ROS2** (`pj_bridge_ros2`) — ROS2 Humble / Jazzy / Kilted / Lyrical via `rclcpp`
 - **FastDDS** (`pj_bridge_fastdds`) — eProsima Fast DDS 3.4 (standalone, no ROS2 required)
 - **RTI** (`pj_bridge_rti`) — RTI Connext DDS (build disabled, code preserved)
 
@@ -34,10 +34,10 @@ independently.
 
 ## CI Status
 
-|  | Humble | Jazzy | Kilted |
-|--|--------|-------|--------|
-| **Pixi** | [![Pixi: Humble](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_humble.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_humble.yaml) | [![Pixi: Jazzy](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_jazzy.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_jazzy.yaml) | [![Pixi: Kilted](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_kilted.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_kilted.yaml) |
-| **colcon** | [![ROS: Humble](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_humble.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_humble.yaml) | [![ROS: Jazzy](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_jazzy.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_jazzy.yaml) | [![ROS: Kilted](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_kilted.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_kilted.yaml) |
+|  | Humble | Jazzy | Kilted | Lyrical |
+|--|--------|-------|--------|---------|
+| **Pixi** | [![Pixi: Humble](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_humble.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_humble.yaml) | [![Pixi: Jazzy](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_jazzy.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_jazzy.yaml) | [![Pixi: Kilted](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_kilted.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/pixi_kilted.yaml) | — |
+| **colcon** | [![ROS: Humble](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_humble.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_humble.yaml) | [![ROS: Jazzy](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_jazzy.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_jazzy.yaml) | [![ROS: Kilted](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_kilted.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_kilted.yaml) | [![ROS: Lyrical](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_lyrical.yaml/badge.svg?branch=main)](https://github.com/PlotJuggler/plotjuggler_bridge/actions/workflows/ros_lyrical.yaml) |
 
 ## Configuration Parameters
 
@@ -50,8 +50,9 @@ independently.
 | `session_timeout` | double | 10.0 | Client timeout duration in seconds |
 | `strip_large_messages` | bool | false | Opt-in: strip large arrays from Image, PointCloud2, LaserScan, OccupancyGrid messages |
 | `topic_whitelist` | string array | `[".*"]` | Full-match regex patterns (ECMAScript) restricting visible/subscribable topics |
-| `min_qos_depth` | int | 1 | ROS2 only: minimum KEEP_LAST subscription depth after aggregating publisher depths |
+| `min_qos_depth` | int | 10 | ROS2 only: minimum KEEP_LAST subscription depth after aggregating publisher depths |
 | `max_qos_depth` | int | 100 | ROS2 only: maximum KEEP_LAST subscription depth after aggregating publisher depths |
+| `ingest_poll_interval_ms` | double | 5.0 | ROS2 only: interval between ingest executor polls; subscription callbacks drain their DDS reader each poll. `0` uses a blocking spin instead |
 | `topic_poll_interval` | double | 1.0 | Seconds between `topics_changed` notification polls; `0` disables polling |
 | `client_backlog_size` | int | 100 | Max binary frames queued per slow client before the oldest is dropped (must be `> 0`) |
 | `heavy_frame_threshold_bytes` | int | 262144 | Isolate messages ≥ this size (bytes) into their own size-class frame so they don't starve small topics; `0` disables (must be `>= 0`) |

diff --git a/app/src/message_buffer.cpp b/app/src/message_buffer.cpp
@@ -55,6 +55,12 @@ void MessageBuffer::set_latched(const std::string& topic_name, bool latched) {
   std::lock_guard<std::mutex> lock(mutex_);
   if (latched) {
     latched_topics_.insert(topic_name);
+    // Ingest may run on another thread: the retained sample can already be
+    // buffered by the time the subscriber's bookkeeping gets here.
+    auto it = topic_buffers_.find(topic_name);
+    if (latched_last_.count(topic_name) == 0 && it != topic_buffers_.end() && !it->second.empty()) {
+      latched_last_[topic_name] = it->second.back();
+    }
   } else {
     latched_topics_.erase(topic_name);
     latched_last_.erase(topic_name);

diff --git a/app/src/message_serializer.cpp b/app/src/message_serializer.cpp
@@ -53,9 +53,9 @@ void AggregatedMessageSerializer::serialize_message(
   write_le(serialized_data_, msg_size);
 
   // Message data (CDR bytes) using memcpy
-  size_t old_size = serialized_data_.size();
-  serialized_data_.resize(old_size + msg_size);
-  std::memcpy(serialized_data_.data() + old_size, data, msg_size);
+  // insert, not resize+memcpy: resize would zero the bytes first
+  const auto *bytes = reinterpret_cast<const uint8_t *>(data);
+  serialized_data_.insert(serialized_data_.end(), bytes, bytes + msg_size);
 }
 
 void AggregatedMessageSerializer::clear() {

diff --git a/app/src/middleware/websocket_middleware.cpp b/app/src/middleware/websocket_middleware.cpp
@@ -74,6 +74,8 @@ tl::expected<void, std::string> WebSocketMiddleware::initialize(uint16_t port) {
   }
 
   server_ = std::make_shared<ix::WebSocketServer>(port, "0.0.0.0");
+  // Binary frames are already zstd-compressed; deflating them again is wasted work.
+  server_->disablePerMessageDeflate();
 
 #ifdef IXWEBSOCKET_USE_TLS
   if (tls_.has_value()) {

diff --git a/conanfile.txt b/conanfile.txt
@@ -1,6 +1,6 @@
 [requires]
-fast-dds/3.4.0
-cli11/2.6.0
+fast-dds/3.4.3
+cli11/2.6.2
 
 [generators]
 CMakeDeps

diff --git a/docs/API.md b/docs/API.md
@@ -208,7 +208,7 @@ offers (so a burst from every publisher still fits in the subscription
 queue), then clamping the total to a configurable range — the same heuristic
 `foxglove_bridge`'s `determineQoS()` uses:
 
-- **ROS2**: int parameters `min_qos_depth` (default `1`) and `max_qos_depth`
+- **ROS2**: int parameters `min_qos_depth` (default `10`) and `max_qos_depth`
   (default `100`).
 
 A publisher that reports depth `0` (KEEP_ALL, or an RMW such as
@@ -223,6 +223,26 @@ match what the discovered publishers offer (a RELIABLE subscription still
 switches to BEST_EFFORT if any publisher is BEST_EFFORT, and to
 TRANSIENT_LOCAL only if every publisher offers it).
 
+`min_qos_depth` defaults to `10` (rather than `1`) so the ingest poll
+interval below can't overflow a shallow reader between polls.
+
+## Ingest Poll Interval (ROS2 only)
+
+The ROS2 backend's ingest executor (the one running subscription callbacks)
+polls via `spin_some()` on a timer instead of blocking in `spin()`: `rclcpp`
+rebuilds its whole wait set — O(subscriptions) — on every wait cycle, which
+with `spin()` means one rebuild per received message. Polling amortizes one
+rebuild over every message that arrived in the poll interval; subscription
+callbacks drain their DDS reader on each poll, so nothing is lost as long as
+the reader depth (`min_qos_depth`) covers a burst.
+
+- **ROS2**: double parameter `ingest_poll_interval_ms` (default `5.0`,
+  milliseconds). `0` reverts to a blocking `spin()`. Must be `>= 0`; the
+  server refuses to start otherwise.
+
+Publish/request/session-timeout timers run on their own executor thread so a
+long publish (zstd-compression) cycle never delays ingest.
+
 ## Subscribe
 
 Subscribe to one or more topics. **Breaking change:** Subscribe now uses an additive model - it only adds topics without removing existing subscriptions. Use the `unsubscribe` command to remove topics.

diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
@@ -152,7 +152,7 @@ Unlike the RTI backend's 4-class two-level design (discovery + subscription mana
 - **FastDdsTopicSource**: Manages `DomainParticipant`s, discovers topics via `DomainParticipantListener::on_data_writer_discovery()`, resolves `DynamicType` from `TypeObjectRegistry`, generates IDL schema via `idl_serialize()`. Also provides `get_dynamic_type()` / `get_participant()` / `get_domain_id()` for use by the subscription manager.
 - **FastDdsSubscriptionManager**: Creates `DataReader`s with `DynamicPubSubType`, ref-counted subscriptions. Extracts CDR bytes by deserializing into `DynamicData` and re-serializing via `DynamicPubSubType::serialize()`.
 
-FastDDS dependencies are managed via Conan (`fast-dds/3.4.0`). The backend is built standalone (not through colcon/ament).
+FastDDS dependencies are managed via Conan (`fast-dds/3.4.3`). The backend is built standalone (not through colcon/ament).
 
 ## Design Decisions
 

diff --git a/fastdds/src/fastdds_subscription_manager.cpp b/fastdds/src/fastdds_subscription_manager.cpp
@@ -80,8 +80,8 @@ class FastDdsSubscriptionManager::InternalReaderListener : public DataReaderList
           continue;
         }
 
-        auto cdr_data = std::make_shared<std::vector<std::byte>>(payload_.length);
-        std::memcpy(cdr_data->data(), payload_.data, payload_.length);
+        const auto* bytes = reinterpret_cast<const std::byte*>(payload_.data);
+        auto cdr_data = std::make_shared<std::vector<std::byte>>(bytes, bytes + payload_.length);
 
         uint64_t timestamp_ns =
             static_cast<uint64_t>(info.source_timestamp.seconds()) * 1'000'000'000ULL + info.source_timestamp.nanosec();

diff --git a/ros2/include/pj_bridge_ros2/generic_subscription_manager.hpp b/ros2/include/pj_bridge_ros2/generic_subscription_manager.hpp
@@ -54,6 +54,7 @@ class GenericSubscriptionManager {
   bool unsubscribe(const std::string& topic_name);
   bool is_subscribed(const std::string& topic_name) const;
   size_t get_reference_count(const std::string& topic_name) const;
+  size_t subscription_count() const;
   void unsubscribe_all();
 
   /// True when the subscription for `topic_name` was created with

diff --git a/ros2/include/pj_bridge_ros2/ros2_subscription_manager.hpp b/ros2/include/pj_bridge_ros2/ros2_subscription_manager.hpp
@@ -50,6 +50,7 @@ class Ros2SubscriptionManager : public SubscriptionManagerInterface {
   void unsubscribe_all() override;
   bool is_transient_local(const std::string& topic_name) const override;
   bool is_subscribed(const std::string& topic_name) const override;
+  size_t subscription_count() const;
 
  private:
   GenericSubscriptionManager inner_manager_;