diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "ClangdLSPServer.h"
+#include "ClangdServer.h"
 #include "CodeComplete.h"
 #include "Diagnostics.h"
 #include "DraftStore.h"
@@ -26,6 +27,7 @@
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/iterator_range.h"
+#include "llvm/Support/Allocator.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FormatVariadic.h"
@@ -145,6 +147,16 @@
                LastInvalidFile, InvalidFileCount - 1);
 }
 
+void profile(const ClangdServer &Server, bool Detailed) {
+  trace::Span Tracer(Detailed ? "ProfileDetailed" : "ProfileBrief");
+  // Exit early if tracing is disabled.
+  if (!Tracer.Args)
+    return;
+  llvm::BumpPtrAllocator DetailAlloc;
+  MemoryTree MT(Detailed ? &DetailAlloc : nullptr);
+  Server.profile(MT);
+  trace::recordMemoryUsage(MT, "clangd_server");
+}
 } // namespace
 
 // MessageHandler dispatches incoming LSP messages.
@@ -163,14 +175,18 @@
     log("<-- {0}", Method);
     if (Method == "exit")
       return false;
-    if (!Server.Server)
+    if (!Server.Server) {
       elog("Notification {0} before initialization", Method);
-    else if (Method == "$/cancelRequest")
+    } else if (Method == "$/cancelRequest") {
       onCancel(std::move(Params));
-    else if (auto Handler = Notifications.lookup(Method))
+    } else if (auto Handler = Notifications.lookup(Method)) {
       Handler(std::move(Params));
-    else
+      // Record memory usage after each notification. This currently takes <1ms,
+      // so it is safe to do frequently.
+      profile(*Server.Server, /*Detailed=*/false);
+    } else {
       log("unhandled notification {0}", Method);
+    }
     return true;
   }
 
diff --git a/clang-tools-extra/clangd/ClangdServer.h b/clang-tools-extra/clangd/ClangdServer.h
--- a/clang-tools-extra/clangd/ClangdServer.h
+++ b/clang-tools-extra/clangd/ClangdServer.h
@@ -25,6 +25,7 @@
 #include "refactor/Tweak.h"
 #include "support/Cancellation.h"
 #include "support/Function.h"
+#include "support/MemoryTree.h"
 #include "support/ThreadsafeFS.h"
 #include "clang/Tooling/CompilationDatabase.h"
 #include "clang/Tooling/Core/Replacement.h"
@@ -340,6 +341,9 @@
   LLVM_NODISCARD bool
   blockUntilIdleForTest(llvm::Optional<double> TimeoutSeconds = 10);
 
+  /// Builds a nested representation of memory used by components.
+  void profile(MemoryTree &MT) const;
+
 private:
   void formatCode(PathRef File, llvm::StringRef Code,
                   ArrayRef<tooling::Range> Ranges,
diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -28,6 +28,7 @@
 #include "refactor/Tweak.h"
 #include "support/Logger.h"
 #include "support/Markup.h"
+#include "support/MemoryTree.h"
 #include "support/ThreadsafeFS.h"
 #include "support/Trace.h"
 #include "clang/Format/Format.h"
@@ -824,5 +825,12 @@
           BackgroundIdx->blockUntilIdleForTest(TimeoutSeconds));
 }
 
+void ClangdServer::profile(MemoryTree &MT) const {
+  if (DynamicIdx)
+    DynamicIdx->profile(MT.child("dynamic_index"));
+  if (BackgroundIdx)
+    BackgroundIdx->profile(MT.child("background_index"));
+  WorkScheduler.profile(MT.child("tuscheduler"));
+}
 } // namespace clangd
 } // namespace clang
diff --git a/clang-tools-extra/clangd/unittests/ClangdLSPServerTests.cpp b/clang-tools-extra/clangd/unittests/ClangdLSPServerTests.cpp
--- a/clang-tools-extra/clangd/unittests/ClangdLSPServerTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ClangdLSPServerTests.cpp
@@ -164,6 +164,17 @@
   stop();
   EXPECT_THAT(Tracer.takeMetric("lsp_latency", MethodName), testing::SizeIs(1));
 }
+
+TEST_F(LSPTest, RecordsMemoryUsage) {
+  trace::TestTracer Tracer;
+  auto &Client = start();
+  EXPECT_THAT(Tracer.takeMetric("memory_usage", "clangd_server"),
+              testing::SizeIs(0));
+  Client.notify("", {});
+  stop();
+  EXPECT_THAT(Tracer.takeMetric("memory_usage", "clangd_server"),
+              testing::SizeIs(1));
+}
 } // namespace
 } // namespace clangd
 } // namespace clang
diff --git a/clang-tools-extra/clangd/unittests/ClangdTests.cpp b/clang-tools-extra/clangd/unittests/ClangdTests.cpp
--- a/clang-tools-extra/clangd/unittests/ClangdTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ClangdTests.cpp
@@ -17,6 +17,7 @@
 #include "TestFS.h"
 #include "TestTU.h"
 #include "URI.h"
+#include "support/MemoryTree.h"
 #include "support/Path.h"
 #include "support/Threading.h"
 #include "clang/Config/config.h"
@@ -27,6 +28,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Allocator.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Regex.h"
@@ -48,6 +50,7 @@
 namespace {
 
 using ::testing::AllOf;
+using ::testing::Contains;
 using ::testing::ElementsAre;
 using ::testing::Field;
 using ::testing::Gt;
@@ -1236,6 +1239,21 @@
   EXPECT_FALSE(DiagConsumer.HadDiagsInLastCallback);
 }
 
+TEST(ClangdServer, MemoryUsageTest) {
+  MockFS FS;
+  MockCompilationDatabase CDB;
+  ClangdServer Server(CDB, FS, ClangdServer::optsForTest());
+
+  auto FooCpp = testPath("foo.cpp");
+  Server.addDocument(FooCpp, "");
+  ASSERT_TRUE(Server.blockUntilIdleForTest());
+
+  llvm::BumpPtrAllocator Alloc;
+  MemoryTree MT(&Alloc);
+  Server.profile(MT);
+  ASSERT_TRUE(MT.children().count("tuscheduler"));
+  EXPECT_TRUE(MT.child("tuscheduler").children().count(FooCpp));
+}
 } // namespace
 } // namespace clangd
 } // namespace clang