Fix code review findings: security, correctness, performance, dead code

Security:
- Add SQL identifier validation to DbOptimizer.analyze_table/vacuum_table
- Move health/readiness routes to non-rate-limited pipeline

Correctness:
- Fix monitor reference leak in StreamingPacketsPubSub (track refs, demonitor on unsubscribe)
- Persist circuit breaker half-open state transitions
- Simplify ShutdownHandler.terminate to avoid pointless Process.send_after

Performance:
- Batch marker removal into single WebSocket event (remove_markers_batch)
- Use Task.Supervisor.start_child for fire-and-forget broadcasts

Dead code removal:
- Remove copy_insert/regular_batch_insert/rows_to_csv from DbOptimizer
- Remove dead packet_pipeline_integration tests
- Remove unused telemetry event detach

Other:
- Fix Callsign.valid? docstring to match permissive behavior
- Fix DatabaseMetrics to delegate instead of hardcoding pool stats
- Add circuit breaker and encoding test coverage

assets/js/map.ts

@@ -869,6 +869,11 @@ let MapAPRSMap = {
       self.removeMarker(data.id);
     });
 
+    // Remove markers in batch
+    self.handleEvent("remove_markers_batch", (data: { ids: string[] }) => {
+      data.ids.forEach((id) => self.removeMarker(id));
+    });
+
     // Clear all markers
     self.handleEvent("clear_markers", () => {
       self.clearAllMarkers();

lib/aprsme/broadcast_task_supervisor.ex

@@ -35,27 +35,29 @@ defmodule Aprsme.BroadcastTaskSupervisor do
   @doc """
   Broadcasts a message to multiple topics asynchronously using the task pool.
 
+  Uses `Task.Supervisor.start_child/2` for fire-and-forget execution.
+  The spawned task is not linked to the caller and does not send reply
+  messages back, avoiding orphaned `{ref, result}` and `:DOWN` messages
+  in the calling process mailbox.
+
   ## Parameters
     - topics: List of PubSub topics to broadcast to
     - message: The message to broadcast
     - pubsub: The PubSub server (defaults to Aprsme.PubSub)
 
   ## Returns
-    - {:ok, task_ref} where task_ref can be used to await results if needed
+    - {:ok, pid} of the spawned task
   """
   def broadcast_async(topics, message, pubsub \\ Aprsme.PubSub) do
-    task =
+    Task.Supervisor.start_child(@pool_name, fn ->
-      Task.Supervisor.async_nolink(@pool_name, fn ->
+      # Use Stream for memory efficiency with large topic lists
-        # Use Stream for memory efficiency with large topic lists
+      topics
-        topics
+      # Process in chunks to balance load
-        # Process in chunks to balance load
+      |> Stream.chunk_every(10)
-        |> Stream.chunk_every(10)
+      |> Enum.each(fn topic_chunk ->
-        |> Enum.each(fn topic_chunk ->
+        broadcast_to_topics(topic_chunk, message, pubsub)
-          broadcast_to_topics(topic_chunk, message, pubsub)
-        end)
       end)
-
+    end)
-    {:ok, task}
   end
 
   @doc """

lib/aprsme/callsign.ex

@@ -18,20 +18,28 @@ defmodule Aprsme.Callsign do
   def normalize(_), do: ""
 
   @doc """
-  Validates if a callsign format is reasonable for amateur radio use.
+  Checks whether a callsign is a non-empty string.
+
+  APRS uses a wide variety of identifiers beyond standard amateur radio
+  callsigns, including tactical callsigns, object names, and item names.
+  This function intentionally accepts any non-empty, non-whitespace-only
+  string to accommodate that variety.
 
   ## Examples
-      
+
       iex> Aprsme.Callsign.valid?("W5ABC")
       true
-      
+
       iex> Aprsme.Callsign.valid?("W5ABC-15")
       true
-      
+
+      iex> Aprsme.Callsign.valid?("TACTICAL1")
+      true
+
       iex> Aprsme.Callsign.valid?("")
       false
-      
+
-      iex> Aprsme.Callsign.valid?("A")
+      iex> Aprsme.Callsign.valid?(nil)
       false
   """
   @spec valid?(String.t() | nil) :: boolean()
@@ -40,7 +48,8 @@ defmodule Aprsme.Callsign do
   def valid?(callsign) when is_binary(callsign) do
     trimmed = String.trim(callsign)
 
-    # Accept any non-empty callsign
+    # Accept any non-empty callsign — APRS uses tactical callsigns,
+    # object names, and other non-standard identifiers
     trimmed != ""
   end
 

lib/aprsme/circuit_breaker.ex

@@ -89,6 +89,18 @@ defmodule Aprsme.CircuitBreaker do
   def handle_call({:get_state, service_name}, _from, services) do
     service_state = get_service_state(services, service_name)
     current_state = calculate_current_state(service_state)
+
+    # Persist state transitions (e.g., :open -> :half_open) so that
+    # concurrent callers see the same state and don't all independently
+    # enter half_open.
+    services =
+      if current_state == service_state.state do
+        services
+      else
+        updated_state = %{service_state | state: current_state}
+        Map.put(services, service_name, updated_state)
+      end
+
     {:reply, current_state, services}
   end
 

lib/aprsme/db_optimizer.ex

@@ -16,34 +16,6 @@ defmodule Aprsme.DbOptimizer do
 
   require Logger
 
-  @doc """
-  Execute a large batch insert using PostgreSQL COPY command for maximum performance.
-  This is significantly faster than INSERT for large datasets.
-  """
-  def copy_insert(table_name, columns, rows) when length(rows) > 1000 do
-    # Convert rows to CSV format for COPY
-    csv_data = rows_to_csv(rows, columns)
-
-    # Use COPY command which bypasses much of the overhead of INSERT
-    query = """
-    COPY #{table_name} (#{Enum.join(columns, ", ")})
-    FROM STDIN WITH (FORMAT csv, HEADER false)
-    """
-
-    SQL.query!(Repo, query, [csv_data])
-    length(rows)
-  rescue
-    error ->
-      Logger.error("COPY insert failed: #{inspect(error)}")
-      # Fall back to regular insert
-      regular_batch_insert(table_name, columns, rows)
-  end
-
-  def copy_insert(table_name, columns, rows) do
-    # For smaller batches, use regular insert
-    regular_batch_insert(table_name, columns, rows)
-  end
-
   @doc """
   Optimized batch insert that leverages PostgreSQL configuration
   """
@@ -103,6 +75,7 @@ defmodule Aprsme.DbOptimizer do
   This helps PostgreSQL make better query plans
   """
   def analyze_table(table_name) do
+    validate_identifier!(table_name)
     SQL.query!(Repo, "ANALYZE #{table_name}", [])
     :ok
   rescue
@@ -116,6 +89,7 @@ defmodule Aprsme.DbOptimizer do
   Use this after large delete operations
   """
   def vacuum_table(table_name, opts \\ []) do
+    validate_identifier!(table_name)
     full = Keyword.get(opts, :full, false)
     analyze = Keyword.get(opts, :analyze, true)
 
@@ -165,40 +139,13 @@ defmodule Aprsme.DbOptimizer do
 
   # Private functions
 
-  defp regular_batch_insert(table_name, columns, rows) do
+  defp validate_identifier!(name) when is_binary(name) do
-    # Convert to maps for Ecto.insert_all
+    if !Regex.match?(~r/\A[a-zA-Z_][a-zA-Z0-9_]*\z/, name) do
-    entries =
+      raise ArgumentError, "invalid SQL identifier: #{inspect(name)}"
-      Enum.map(rows, fn row ->
-        columns |> Enum.zip(row) |> Map.new()
-      end)
-
-    {count, _} =
-      Repo.insert_all(table_name, entries,
-        returning: false,
-        on_conflict: :nothing,
-        timeout: 60_000
-      )
-
-    count
-  end
-
-  defp rows_to_csv(rows, _columns) do
-    Enum.map_join(rows, "\n", fn row ->
-      Enum.map_join(row, ",", &escape_csv_value/1)
-    end)
-  end
-
-  defp escape_csv_value(nil), do: ""
-
-  defp escape_csv_value(value) when is_binary(value) do
-    if String.contains?(value, [",", "\"", "\n"]) do
-      "\"#{String.replace(value, "\"", "\"\"")}\""
-    else
-      value
     end
   end
 
-  defp escape_csv_value(value), do: to_string(value)
+  defp validate_identifier!(name) when is_atom(name), do: validate_identifier!(Atom.to_string(name))
 
   # Default 1KB
   defp estimate_entry_size(nil), do: 1024

lib/aprsme/shutdown_handler.ex

@@ -83,8 +83,12 @@ defmodule Aprsme.ShutdownHandler do
       end
 
     if should_graceful_shutdown and not state.shutting_down do
-      initiate_shutdown(state)
+      # Mark unhealthy so load balancer stops sending traffic, then
-      # Give some time for the shutdown process
+      # block for drain_timeout to let existing connections finish.
+      # Note: Process.send_after is pointless here since no messages
+      # are processed during terminate — we just sleep directly.
+      mark_unhealthy()
+      stop_accepting_connections()
       Process.sleep(state.drain_timeout)
     end
 

lib/aprsme/streaming_packets_pubsub.ex

@@ -66,20 +66,24 @@ defmodule Aprsme.StreamingPacketsPubSub do
     # Monitor subscribers for cleanup
     Process.flag(:trap_exit, true)
 
-    {:ok, %{}}
+    # pid => monitor_ref — track monitors to demonitor on unsubscribe/update
+    {:ok, %{monitors: %{}}}
   end
 
   @impl true
   def handle_call({:subscribe, pid, bounds}, _from, state) do
     # Validate bounds
     if valid_bounds?(bounds) do
+      # Demonitor old ref if this pid was already subscribed (bounds update)
+      state = demonitor_if_exists(state, pid)
+
       # Monitor the subscriber
-      Process.monitor(pid)
+      ref = Process.monitor(pid)
 
       # Store in ETS for fast lookup
       :ets.insert(@table_name, {pid, bounds})
 
-      {:reply, :ok, state}
+      {:reply, :ok, put_in(state.monitors[pid], ref)}
     else
       {:reply, {:error, :invalid_bounds}, state}
     end
@@ -87,6 +91,7 @@ defmodule Aprsme.StreamingPacketsPubSub do
 
   @impl true
   def handle_call({:unsubscribe, pid}, _from, state) do
+    state = demonitor_if_exists(state, pid)
     :ets.delete(@table_name, pid)
     {:reply, :ok, state}
   end
@@ -130,11 +135,22 @@ defmodule Aprsme.StreamingPacketsPubSub do
   def handle_info({:DOWN, _ref, :process, pid, _reason}, state) do
     # Clean up subscriber when process dies
     :ets.delete(@table_name, pid)
-    {:noreply, state}
+    {:noreply, %{state | monitors: Map.delete(state.monitors, pid)}}
   end
 
   # Private functions
 
+  defp demonitor_if_exists(state, pid) do
+    case Map.pop(state.monitors, pid) do
+      {nil, _monitors} ->
+        state
+
+      {ref, monitors} ->
+        Process.demonitor(ref, [:flush])
+        %{state | monitors: monitors}
+    end
+  end
+
   defp valid_bounds?(%{north: n, south: s, east: e, west: w}) do
     all_bounds_numeric?(n, s, e, w) and
       n >= s and

lib/aprsme/telemetry/database_metrics.ex

@@ -75,14 +75,9 @@ defmodule Aprsme.Telemetry.DatabaseMetrics do
   end
 
   defp report_pool_metrics_estimated(pool_size) do
-    emit_pool_metrics(%{
+    # Cannot reliably introspect DBConnection pool state, so report
-      size: pool_size,
+    # pool_size as total without guessing busy/idle breakdown.
-      idle: max(0, pool_size - 2),
+    report_pool_metrics_idle(pool_size)
-      busy: 2,
-      available: max(0, pool_size - 2),
-      queue_length: 0,
-      total: pool_size
-    })
   end
 
   defp report_pool_metrics_error do

lib/aprsme_web/live/map_live/display_manager.ex

@@ -118,9 +118,7 @@ defmodule AprsmeWeb.MapLive.DisplayManager do
   def remove_markers_batch(socket, []), do: socket
 
   def remove_markers_batch(socket, marker_ids) do
-    Enum.reduce(marker_ids, socket, fn id, acc ->
+    LiveView.push_event(socket, "remove_markers_batch", %{ids: marker_ids})
-      LiveView.push_event(acc, "remove_marker", %{id: id})
-    end)
   end
 
   # Placeholder for historical loading function - this should be moved to HistoricalLoader

lib/aprsme_web/router.ex

@@ -31,6 +31,10 @@ defmodule AprsmeWeb.Router do
     plug RateLimiter, scale: 60_000, limit: 100
   end
 
+  pipeline :accepts_json do
+    plug :accepts, ["json"]
+  end
+
   pipeline :api do
     plug :accepts, ["json"]
     plug RateLimiter, scale: 60_000, limit: 100
@@ -51,9 +55,9 @@ defmodule AprsmeWeb.Router do
     end
   end
 
+  # Health/readiness routes — no rate limiting to avoid false K8s probe failures
   scope "/", AprsmeWeb do
-    pipe_through :public_api
+    pipe_through :accepts_json
-    get "/health", PageController, :health
     get "/ready", PageController, :ready
     get "/status.json", PageController, :status_json
   end

lib/aprsme_web/telemetry.ex

@@ -114,8 +114,6 @@ defmodule AprsmeWeb.Telemetry do
         description: "Backpressure state changes"
       ),
 
-      # Note: SystemMonitor and InsertOptimizer metrics removed after reverting performance optimizations
-
       # Spatial PubSub Metrics
       last_value("aprsme.spatial_pubsub.clients.count", description: "Number of connected clients"),
       last_value("aprsme.spatial_pubsub.clients.grid_cells", description: "Number of active grid cells"),

test/aprsme/broadcast_task_supervisor_test.exs

@@ -15,6 +15,14 @@ defmodule Aprsme.BroadcastTaskSupervisorTest do
   end
 
   describe "broadcast_async/3" do
+    test "returns {:ok, pid} for fire-and-forget execution", %{test_topic: test_topic} do
+      topics = [test_topic]
+      message = {:test_message, "Hello from broadcast"}
+
+      assert {:ok, pid} = BroadcastTaskSupervisor.broadcast_async(topics, message)
+      assert is_pid(pid)
+    end
+
     test "broadcasts messages to multiple topics asynchronously", %{test_topic: test_topic} do
       # Create additional test topics
       topic2 = "test_topic_2_#{System.unique_integer()}"
@@ -26,16 +34,27 @@ defmodule Aprsme.BroadcastTaskSupervisorTest do
       topics = [test_topic, topic2, topic3]
       message = {:test_message, "Hello from broadcast"}
 
-      # Broadcast to all topics
+      # Broadcast to all topics (fire-and-forget)
-      {:ok, task} = BroadcastTaskSupervisor.broadcast_async(topics, message)
+      {:ok, _pid} = BroadcastTaskSupervisor.broadcast_async(topics, message)
-
-      # Wait for the task to complete
-      Task.await(task)
 
       # Should receive the message on all topics
-      assert_receive {:test_message, "Hello from broadcast"}
+      assert_receive {:test_message, "Hello from broadcast"}, 1000
-      assert_receive {:test_message, "Hello from broadcast"}
+      assert_receive {:test_message, "Hello from broadcast"}, 1000
-      assert_receive {:test_message, "Hello from broadcast"}
+      assert_receive {:test_message, "Hello from broadcast"}, 1000
+    end
+
+    test "does not send task ref or DOWN messages to calling process", %{test_topic: test_topic} do
+      topics = [test_topic]
+      message = {:test_ref_check, "checking refs"}
+
+      {:ok, _pid} = BroadcastTaskSupervisor.broadcast_async(topics, message)
+
+      # Wait for the broadcast to complete
+      assert_receive {:test_ref_check, "checking refs"}, 1000
+
+      # Ensure no {ref, result} or {:DOWN, ...} messages leaked into our mailbox
+      refute_receive {_ref, _result}, 100
+      refute_receive {:DOWN, _ref, :process, _pid, _reason}, 100
     end
 
     test "handles large topic lists efficiently", %{test_topic: test_topic} do
@@ -54,16 +73,14 @@ defmodule Aprsme.BroadcastTaskSupervisorTest do
 
       # Measure time
       start_time = System.monotonic_time(:millisecond)
-      {:ok, task} = BroadcastTaskSupervisor.broadcast_async(topics, message)
+      {:ok, _pid} = BroadcastTaskSupervisor.broadcast_async(topics, message)
-      Task.await(task, 5000)
+
+      # Wait for delivery to our subscribed topic
+      assert_receive {:bulk_test, "Bulk broadcast"}, 5000
       end_time = System.monotonic_time(:millisecond)
 
       # Should complete in a reasonable time (under 1 second for 101 topics)
-      # Using a more lenient timeout to avoid failures on slower systems or CI
       assert end_time - start_time < 1000
-
-      # Verify we received the message
-      assert_receive {:bulk_test, "Bulk broadcast"}
     end
   end
 
@@ -141,16 +158,11 @@ defmodule Aprsme.BroadcastTaskSupervisorTest do
       # Subscribe to only the first topic
       Phoenix.PubSub.subscribe(Aprsme.PubSub, List.first(topics))
 
-      # Launch 100 concurrent broadcasts
+      # Launch 100 concurrent broadcasts (fire-and-forget)
-      tasks =
+      for i <- 1..100 do
-        for i <- 1..100 do
+        message = {:perf_test, i}
-          message = {:perf_test, i}
+        {:ok, _pid} = BroadcastTaskSupervisor.broadcast_async(topics, message)
-          {:ok, task} = BroadcastTaskSupervisor.broadcast_async(topics, message)
+      end
-          task
-        end
-
-      # Wait for all tasks to complete
-      Enum.each(tasks, &Task.await(&1, 5000))
 
       # Each topic should receive 100 messages
       message_count = receive_all_messages()

test/aprsme/circuit_breaker_test.exs

@@ -0,0 +1,190 @@
+defmodule Aprsme.CircuitBreakerTest do
+  use ExUnit.Case, async: false
+
+  import ExUnit.CaptureLog
+
+  alias Aprsme.CircuitBreaker
+
+  # Use unique service names per test to avoid cross-test interference
+  # since CircuitBreaker is already started by the application.
+  # CircuitBreaker.call/3 uses Task.async internally, so errors in the
+  # called function produce EXIT signals. We trap exits in the test process.
+
+  setup do
+    Process.flag(:trap_exit, true)
+    :ok
+  end
+
+  describe "state transitions" do
+    test "starts in closed state for unknown service" do
+      assert CircuitBreaker.get_state(:cb_test_closed) == :closed
+    end
+
+    test "transitions to open after reaching failure threshold" do
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_open, fn -> raise "fail" end)
+        end
+      end)
+
+      assert CircuitBreaker.get_state(:cb_test_open) == :open
+    end
+
+    test "stays closed when below failure threshold" do
+      capture_log(fn ->
+        for _ <- 1..4 do
+          CircuitBreaker.call(:cb_test_below, fn -> raise "fail" end)
+        end
+      end)
+
+      assert CircuitBreaker.get_state(:cb_test_below) == :closed
+    end
+
+    test "resets failure count on success" do
+      capture_log(fn ->
+        for _ <- 1..3 do
+          CircuitBreaker.call(:cb_test_reset_count, fn -> raise "fail" end)
+        end
+      end)
+
+      CircuitBreaker.call(:cb_test_reset_count, fn -> :ok end)
+
+      stats = CircuitBreaker.get_stats(:cb_test_reset_count)
+      assert stats.failure_count == 0
+      assert stats.state == :closed
+    end
+  end
+
+  describe "half-open state persistence" do
+    test "half_open state is persisted after recovery timeout elapses" do
+      # Trip the breaker
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_persist_ho, fn -> raise "fail" end)
+        end
+      end)
+
+      assert CircuitBreaker.get_state(:cb_test_persist_ho) == :open
+
+      # Manipulate last_failure_time to simulate recovery_timeout having passed
+      :sys.replace_state(CircuitBreaker, fn services ->
+        service_state = Map.get(services, :cb_test_persist_ho)
+
+        updated =
+          Map.put(
+            service_state,
+            :last_failure_time,
+            DateTime.add(DateTime.utc_now(), -60, :second)
+          )
+
+        Map.put(services, :cb_test_persist_ho, updated)
+      end)
+
+      # First call to get_state should return half_open AND persist it
+      assert CircuitBreaker.get_state(:cb_test_persist_ho) == :half_open
+
+      # The persisted state should now be half_open
+      stats = CircuitBreaker.get_stats(:cb_test_persist_ho)
+      assert stats.state == :half_open
+    end
+
+    test "second get_state call returns half_open from persisted state" do
+      # Trip the breaker
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_second_ho, fn -> raise "fail" end)
+        end
+      end)
+
+      # Set last_failure_time to the past
+      :sys.replace_state(CircuitBreaker, fn services ->
+        service_state = Map.get(services, :cb_test_second_ho)
+
+        updated =
+          Map.put(
+            service_state,
+            :last_failure_time,
+            DateTime.add(DateTime.utc_now(), -60, :second)
+          )
+
+        Map.put(services, :cb_test_second_ho, updated)
+      end)
+
+      # First call transitions to half_open and persists
+      assert CircuitBreaker.get_state(:cb_test_second_ho) == :half_open
+
+      # Second call should also return half_open (from persisted state, not recalculated)
+      assert CircuitBreaker.get_state(:cb_test_second_ho) == :half_open
+
+      stats = CircuitBreaker.get_stats(:cb_test_second_ho)
+      assert stats.state == :half_open
+    end
+  end
+
+  describe "call/3" do
+    test "returns {:ok, result} on success" do
+      assert {:ok, 42} = CircuitBreaker.call(:cb_test_call_ok, fn -> 42 end)
+    end
+
+    test "returns {:error, :circuit_open} when circuit is open" do
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_call_open, fn -> raise "fail" end)
+        end
+      end)
+
+      capture_log(fn ->
+        assert {:error, :circuit_open} = CircuitBreaker.call(:cb_test_call_open, fn -> :ok end)
+      end)
+    end
+
+    test "allows calls in half_open state and closes on success" do
+      # Trip the breaker
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_ho_call, fn -> raise "fail" end)
+        end
+      end)
+
+      # Fast-forward past recovery timeout
+      :sys.replace_state(CircuitBreaker, fn services ->
+        service_state = Map.get(services, :cb_test_ho_call)
+
+        updated =
+          Map.put(
+            service_state,
+            :last_failure_time,
+            DateTime.add(DateTime.utc_now(), -60, :second)
+          )
+
+        Map.put(services, :cb_test_ho_call, updated)
+      end)
+
+      # Should be half_open and allow the call
+      assert {:ok, :recovered} = CircuitBreaker.call(:cb_test_ho_call, fn -> :recovered end)
+
+      # Should be back to closed after success
+      assert CircuitBreaker.get_state(:cb_test_ho_call) == :closed
+    end
+  end
+
+  describe "reset/1" do
+    test "resets circuit to closed state" do
+      capture_log(fn ->
+        for _ <- 1..5 do
+          CircuitBreaker.call(:cb_test_reset, fn -> raise "fail" end)
+        end
+      end)
+
+      assert CircuitBreaker.get_state(:cb_test_reset) == :open
+
+      capture_log(fn ->
+        CircuitBreaker.reset(:cb_test_reset)
+      end)
+
+      assert CircuitBreaker.get_state(:cb_test_reset) == :closed
+      stats = CircuitBreaker.get_stats(:cb_test_reset)
+      assert stats.failure_count == 0
+    end
+  end
+end

test/aprsme/encoding_test.exs

@@ -0,0 +1,54 @@
+defmodule Aprsme.EncodingTest do
+  use ExUnit.Case
+
+  alias Aprsme.Encoding
+
+  describe "sanitize_string/1 fast-path for clean strings" do
+    test "returns clean ASCII string unchanged" do
+      input = "VALID1>APRS,WIDE1-1:Test packet"
+      assert Encoding.sanitize_string(input) == input
+    end
+
+    test "returns clean ASCII string with allowed whitespace unchanged" do
+      input = "Hello\tWorld\nNew line\r\nCRLF"
+      result = Encoding.sanitize_string(input)
+      assert result == input
+    end
+
+    test "still cleans strings with control characters" do
+      # String with null byte (control character that should be removed)
+      input = "Hello\x00World"
+      result = Encoding.sanitize_string(input)
+      assert result == "HelloWorld"
+    end
+
+    test "still cleans strings with DEL character" do
+      input = "Hello\x7FWorld"
+      result = Encoding.sanitize_string(input)
+      assert result == "HelloWorld"
+    end
+
+    test "handles empty string" do
+      assert Encoding.sanitize_string("") == ""
+    end
+
+    test "handles non-binary input" do
+      assert Encoding.sanitize_string(nil) == ""
+      assert Encoding.sanitize_string(123) == ""
+    end
+
+    test "handles valid UTF-8 multi-byte characters" do
+      input = "Café résumé"
+      result = Encoding.sanitize_string(input)
+      assert String.valid?(result)
+      assert String.contains?(result, "Caf")
+    end
+
+    test "handles latin1 encoded binary" do
+      # Latin1 bytes for accented characters
+      invalid_binary = <<85, 78, 73, 211, 78, 32, 80, 65, 78, 65, 77, 69, 209, 65>>
+      result = Encoding.sanitize_string(invalid_binary)
+      assert String.valid?(result)
+    end
+  end
+end

test/aprsme/packet_pipeline_integration_test.exs

@@ -1,64 +1,13 @@
 defmodule Aprsme.PacketPipelineIntegrationTest do
   use Aprsme.DataCase, async: false
 
-  import ExUnit.CaptureLog
-
-  alias Aprsme.PacketProducer
   alias Aprsme.Performance.InsertOptimizer
-  alias Aprsme.SystemMonitor
 
   describe "packet pipeline under load" do
-    test "system adjusts batch sizes based on load" do
-      # Test the actual running system without starting new processes
-      initial_batch_size = SystemMonitor.get_recommended_batch_size()
-      assert initial_batch_size >= 100
-      assert initial_batch_size <= 800
-
-      # Submit some packets to the running system
-      log_output =
-        capture_log(fn ->
-          for i <- 1..10 do
-            packet = %{
-              sender: "TEST-#{i}",
-              destination: "APRS",
-              path: "WIDE1-1",
-              information_field: "Integration test packet #{i}",
-              data_type: "position",
-              lat: 40.0 + i / 1000,
-              lon: -74.0 + i / 1000
-            }
-
-            PacketProducer.submit_packet(packet)
-          end
-
-          # Wait a bit for processing
-          Process.sleep(100)
-        end)
-
-      # Verify no errors occurred
-      refute log_output =~ "error"
-    end
-
     test "insert optimizer provides reasonable batch sizes" do
       batch_size = InsertOptimizer.get_optimal_batch_size()
       assert batch_size >= 100
       assert batch_size <= 800
     end
-
-    test "system monitor provides metrics" do
-      metrics = SystemMonitor.get_metrics()
-
-      assert is_map(metrics)
-      assert Map.has_key?(metrics, :memory)
-      assert Map.has_key?(metrics, :cpu)
-      assert Map.has_key?(metrics, :processes)
-      assert Map.has_key?(metrics, :db_pool)
-
-      # Check pressure values are reasonable
-      assert metrics.memory.pressure >= 0.0
-      assert metrics.memory.pressure <= 1.0
-      assert metrics.cpu.pressure >= 0.0
-      assert metrics.cpu.pressure <= 1.0
-    end
   end
 end