fix(electric-telemetry): Fix process_type parsing for request processes that have a request id that is not the standard 20 bytes.

.changeset/process-type-request-id-cardinality.md

@@ -0,0 +1,5 @@
+---
+"@core/electric-telemetry": patch
+---
+
+Fix `process_type` parsing for request processes that have a request id that is not the standard 20 bytes.

packages/electric-telemetry/lib/electric/telemetry/processes.ex

@@ -262,26 +262,43 @@ defmodule ElectricTelemetry.Processes do
   defp parse_binary_label(label) do
     case label do
       "Request " <> <<_req_id::binary-20, " - ", rest::binary>> ->
+        # Fast path: the request id is exactly 20 bytes, as generated by Plug.RequestId.
         # This is a request process with the label assigned by Electric.Plug.LabelProcessPlug.
         # We group all requests together to be able to see their aggregated mem footprint.
+        parse_request_label(rest)
+
+      "Request " <> rest ->
+        # Slow path: the request id has a non-default length (e.g. a UUID or a proxy-supplied
+        # x-request-id), so the fixed-width match above failed. Split on the " - " delimiter
+        # instead so all requests to a route collapse to a single label regardless of id length.
+        case :binary.split(rest, " - ") do
+          [_req_id, request] -> parse_request_label(request)
+          _ -> truncate_label(label)
+        end
 
-        # Cut off the URL query part, leaving only the `<method> <path>` prefix.
-        part_len =
-          case :binary.match(rest, "?") do
-            {pos, _} ->
-              pos
+      _ ->
+        truncate_label(label)
+    end
+  end
 
-            :nomatch ->
-              # No query string means only path is present. It is either a request to the health endpoint or something unexpected.
-              byte_size(rest)
-          end
+  defp parse_request_label(request) do
+    # Cut off the URL query part, leaving only the `<method> <path>` prefix.
+    part_len =
+      case :binary.match(request, "?") do
+        {pos, _} ->
+          pos
 
-        :binary.part(rest, 0, part_len)
+        :nomatch ->
+          # No query string means only path is present. It is either a request to the health endpoint or something unexpected.
+          byte_size(request)
+      end
 
-      _ ->
-        # Opportunistic grouping by truncating long labels.
-        part_len = min(20, byte_size(label))
-        :binary.part(label, 0, part_len)
-    end
+    :binary.part(request, 0, part_len)
+  end
+
+  defp truncate_label(label) do
+    # Opportunistic grouping by truncating long labels.
+    part_len = min(20, byte_size(label))
+    :binary.part(label, 0, part_len)
   end
 end

packages/electric-telemetry/test/electric/telemetry/processes_test.exs

@@ -16,6 +16,27 @@ defmodule ElectricTelemetry.ProcessesTest do
       assert "GET /v1/health" = proc_type(pid)
     end
 
+    test "groups request labels with a non-default-length request id (e.g. a proxy-supplied UUID)" do
+      pid =
+        spawn_with_label(
+          "Request 123e4567-e89b-12d3-a456-426614174000 - GET /v1/shape?table=users&offset=-1"
+        )
+
+      assert "GET /v1/shape" = proc_type(pid)
+    end
+
+    test "groups request labels with a shorter-than-default request id" do
+      pid = spawn_with_label("Request abc123 - GET /v1/health")
+
+      assert "GET /v1/health" = proc_type(pid)
+    end
+
+    test "request label with no \" - \" delimiter is truncated" do
+      pid = spawn_with_label("Request something-without-delimiter")
+
+      assert "Request something-wi" = proc_type(pid)
+    end
+
     test "non-request binary labels are truncated to 20 chars" do
       pid = spawn_with_label("some_long_label_that_exceeds_twenty_characters")
 

packages/sync-service/test/electric/shape_cache_test.exs

@@ -1579,10 +1579,13 @@ defmodule Electric.ShapeCacheTest do
       # explicit `start_consumer_for_handle/2` call is required. The
       # continue runs asynchronously after `start_supervised!` returns,
       # so we wait for the registry to populate.
-      assert wait_until(1000, fn ->
-               not is_nil(Electric.Shapes.ConsumerRegistry.whereis(stack_id, shape_handle)) and
-                 not is_nil(Electric.Shapes.ConsumerRegistry.whereis(stack_id, dep_handle))
-             end)
+      assert wait_until(
+               fn ->
+                 not is_nil(Electric.Shapes.ConsumerRegistry.whereis(stack_id, shape_handle)) and
+                   not is_nil(Electric.Shapes.ConsumerRegistry.whereis(stack_id, dep_handle))
+               end,
+               1000
+             )
 
       # Materializer should be started
       assert Process.alive?(