feat: add more metrics to the Prometheus endpoint

Author: alexandre-daubois

caddy/admin_test.go

@@ -82,6 +82,46 @@ func TestShowTheCorrectThreadDebugStatus(t *testing.T) {
 	assert.Len(t, debugState.ThreadDebugStates, 3)
 }
 
+func TestThreadDebugStateMetricsAfterRequests(t *testing.T) {
+	tester := caddytest.NewTester(t)
+	tester.InitServer(`
+		{
+			skip_install_trust
+			admin localhost:2999
+			http_port `+testPort+`
+
+			frankenphp {
+				num_threads 2
+				worker ../testdata/worker-with-counter.php 1
+			}
+		}
+
+		localhost:`+testPort+` {
+			route {
+				root ../testdata
+				rewrite worker-with-counter.php
+				php
+			}
+		}
+		`, "caddyfile")
+
+	// make a few requests so counters are populated
+	tester.AssertGetResponse("http://localhost:"+testPort+"/", http.StatusOK, "requests:1")
+	tester.AssertGetResponse("http://localhost:"+testPort+"/", http.StatusOK, "requests:2")
+	tester.AssertGetResponse("http://localhost:"+testPort+"/", http.StatusOK, "requests:3")
+
+	debugState := getDebugState(t, tester)
+
+	hasRequestCount := false
+	for _, ts := range debugState.ThreadDebugStates {
+		if ts.RequestCount > 0 {
+			hasRequestCount = true
+			assert.Greater(t, ts.MemoryUsage, int64(0), "thread %d (%s) should report memory usage", ts.Index, ts.Name)
+		}
+	}
+	assert.True(t, hasRequestCount, "at least one thread should have RequestCount > 0 after serving requests")
+}
+
 func TestAutoScaleWorkerThreads(t *testing.T) {
 	wg := sync.WaitGroup{}
 	maxTries := 10

debugstate.go

@@ -1,5 +1,7 @@
 package frankenphp
 
+// #include "frankenphp.h"
+import "C"
 import (
 	"github.com/dunglas/frankenphp/internal/state"
 )
@@ -12,6 +14,11 @@ type ThreadDebugState struct {
 	IsWaiting                bool
 	IsBusy                   bool
 	WaitingSinceMilliseconds int64
+	CurrentURI               string
+	CurrentMethod            string
+	RequestStartedAt         int64
+	RequestCount             int64
+	MemoryUsage              int64
 }
 
 // EXPERIMENTAL: FrankenPHPDebugState prints the state of all PHP threads - debugging purposes only
@@ -39,12 +46,51 @@ func DebugState() FrankenPHPDebugState {
 
 // threadDebugState creates a small jsonable status message for debugging purposes
 func threadDebugState(thread *phpThread) ThreadDebugState {
-	return ThreadDebugState{
+	isBusy := !thread.state.IsInWaitingState()
+
+	s := ThreadDebugState{
 		Index:                    thread.threadIndex,
 		Name:                     thread.name(),
 		State:                    thread.state.Name(),
 		IsWaiting:                thread.state.IsInWaitingState(),
-		IsBusy:                   !thread.state.IsInWaitingState(),
+		IsBusy:                   isBusy,
 		WaitingSinceMilliseconds: thread.state.WaitTime(),
 	}
+
+	s.RequestCount = thread.requestCount.Load()
+	s.MemoryUsage = int64(C.frankenphp_get_thread_memory_usage(C.uintptr_t(thread.threadIndex)))
+
+	if !isBusy {
+		return s
+	}
+
+	thread.handlerMu.RLock()
+	handler := thread.handler
+	thread.handlerMu.RUnlock()
+
+	if handler == nil {
+		return s
+	}
+
+	thread.contextMu.RLock()
+	defer thread.contextMu.RUnlock()
+
+	fc := handler.frankenPHPContext()
+	if fc == nil || fc.request == nil || fc.responseWriter == nil {
+		return s
+	}
+
+	if fc.originalRequest == nil {
+		s.CurrentURI = fc.requestURI
+		s.CurrentMethod = fc.request.Method
+	} else {
+		s.CurrentURI = fc.originalRequest.URL.RequestURI()
+		s.CurrentMethod = fc.originalRequest.Method
+	}
+
+	if !fc.startedAt.IsZero() {
+		s.RequestStartedAt = fc.startedAt.UnixMilli()
+	}
+
+	return s
 }

frankenphp.c

@@ -244,8 +244,13 @@ static void frankenphp_reset_session_state(void) {
 }
 #endif
 
+static frankenphp_thread_metrics *thread_metrics = NULL;
+
 /* Adapted from php_request_shutdown */
 static void frankenphp_worker_request_shutdown() {
+  __atomic_store_n(&thread_metrics[thread_index].last_memory_usage,
+                   zend_memory_usage(0), __ATOMIC_RELAXED);
+
   /* Flush all output buffers */
   zend_try { php_output_end_all(); }
   zend_end_try();
@@ -1233,6 +1238,8 @@ int frankenphp_execute_script(char *file_name) {
     sandboxed_env = NULL;
   }
 
+  __atomic_store_n(&thread_metrics[thread_index].last_memory_usage,
+                   zend_memory_usage(0), __ATOMIC_RELAXED);
   php_request_shutdown((void *)0);
   frankenphp_free_request_context();
 
@@ -1405,6 +1412,20 @@ int frankenphp_reset_opcache(void) {
 
 int frankenphp_get_current_memory_limit() { return PG(memory_limit); }
 
+void frankenphp_init_thread_metrics(int max_threads) {
+  thread_metrics = calloc(max_threads, sizeof(frankenphp_thread_metrics));
+}
+
+void frankenphp_destroy_thread_metrics(void) {
+  free(thread_metrics);
+  thread_metrics = NULL;
+}
+
+size_t frankenphp_get_thread_memory_usage(uintptr_t idx) {
+  return __atomic_load_n(&thread_metrics[idx].last_memory_usage,
+                         __ATOMIC_RELAXED);
+}
+
 static zend_module_entry **modules = NULL;
 static int modules_len = 0;
 static int (*original_php_register_internal_extensions_func)(void) = NULL;

frankenphp.h

@@ -186,6 +186,14 @@ zend_string *frankenphp_init_persistent_string(const char *string, size_t len);
 int frankenphp_reset_opcache(void);
 int frankenphp_get_current_memory_limit();
 
+typedef struct {
+  size_t last_memory_usage;
+} frankenphp_thread_metrics;
+
+void frankenphp_init_thread_metrics(int max_threads);
+void frankenphp_destroy_thread_metrics(void);
+size_t frankenphp_get_thread_memory_usage(uintptr_t thread_index);
+
 void register_extensions(zend_module_entry **m, int len);
 
 #endif

phpmainthread.go

@@ -54,6 +54,8 @@ func initPHPThreads(numThreads int, numMaxThreads int, phpIni map[string]string)
 		return nil, err
 	}
 
+	C.frankenphp_init_thread_metrics(C.int(mainThread.maxThreads))
+
 	// initialize all other threads
 	phpThreads = make([]*phpThread, mainThread.maxThreads)
 	phpThreads[0] = initialThread
@@ -97,6 +99,7 @@ func drainPHPThreads() {
 	doneWG.Wait()
 	mainThread.state.Set(state.Done)
 	mainThread.state.WaitFor(state.Reserved)
+	C.frankenphp_destroy_thread_metrics()
 	phpThreads = nil
 }
 

phpthread.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"runtime"
 	"sync"
+	"sync/atomic"
 	"unsafe"
 
 	"github.com/dunglas/frankenphp/internal/state"
@@ -16,12 +17,14 @@ import (
 // identified by the index in the phpThreads slice
 type phpThread struct {
 	runtime.Pinner
-	threadIndex int
-	requestChan chan contextHolder
-	drainChan   chan struct{}
-	handlerMu   sync.RWMutex
-	handler     threadHandler
-	state       *state.ThreadState
+	threadIndex  int
+	requestChan  chan contextHolder
+	drainChan    chan struct{}
+	handlerMu    sync.RWMutex
+	handler      threadHandler
+	contextMu    sync.RWMutex
+	state        *state.ThreadState
+	requestCount atomic.Int64
 }
 
 // threadHandler defines how the callbacks from the C thread should be handled
@@ -125,10 +128,13 @@ func (thread *phpThread) context() context.Context {
 
 func (thread *phpThread) name() string {
 	thread.handlerMu.RLock()
-	name := thread.handler.name()
-	thread.handlerMu.RUnlock()
+	defer thread.handlerMu.RUnlock()
 
-	return name
+	if thread.handler == nil {
+		return "unknown"
+	}
+
+	return thread.handler.name()
 }
 
 // Pin a string that is not null-terminated

threadregular.go

@@ -60,6 +60,7 @@ func (handler *regularThread) beforeScriptExecution() string {
 }
 
 func (handler *regularThread) afterScriptExecution(_ int) {
+	handler.thread.requestCount.Add(1)
 	handler.afterRequest()
 }
 
@@ -88,8 +89,10 @@ func (handler *regularThread) waitForRequest() string {
 	case ch = <-handler.thread.requestChan:
 	}
 
+	handler.thread.contextMu.Lock()
 	handler.ctx = ch.ctx
 	handler.contextHolder.frankenPHPContext = ch.frankenPHPContext
+	handler.thread.contextMu.Unlock()
 	handler.state.MarkAsWaiting(false)
 
 	// set the scriptFilename that should be executed
@@ -98,8 +101,10 @@ func (handler *regularThread) waitForRequest() string {
 
 func (handler *regularThread) afterRequest() {
 	handler.contextHolder.frankenPHPContext.closeContext()
+	handler.thread.contextMu.Lock()
 	handler.contextHolder.frankenPHPContext = nil
 	handler.ctx = nil
+	handler.thread.contextMu.Unlock()
 }
 
 func handleRequestWithRegularPHPThreads(ch contextHolder) error {

threadworker.go

@@ -131,8 +131,10 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 	// make sure to close the worker request context
 	if handler.workerFrankenPHPContext != nil {
 		handler.workerFrankenPHPContext.closeContext()
+		handler.thread.contextMu.Lock()
 		handler.workerFrankenPHPContext = nil
 		handler.workerContext = nil
+		handler.thread.contextMu.Unlock()
 	}
 
 	// on exit status 0 we just run the worker script again
@@ -235,8 +237,10 @@ func (handler *workerThread) waitForWorkerRequest() (bool, any) {
 	case requestCH = <-handler.worker.requestChan:
 	}
 
+	handler.thread.contextMu.Lock()
 	handler.workerContext = requestCH.ctx
 	handler.workerFrankenPHPContext = requestCH.frankenPHPContext
+	handler.thread.contextMu.Unlock()
 	handler.state.MarkAsWaiting(false)
 
 	if globalLogger.Enabled(requestCH.ctx, slog.LevelDebug) {
@@ -292,9 +296,13 @@ func go_frankenphp_finish_worker_request(threadIndex C.uintptr_t, retval *C.zval
 		fc.handlerReturn = r
 	}
 
+	thread.requestCount.Add(1)
+
 	fc.closeContext()
+	thread.contextMu.Lock()
 	thread.handler.(*workerThread).workerFrankenPHPContext = nil
 	thread.handler.(*workerThread).workerContext = nil
+	thread.contextMu.Unlock()
 
 	if globalLogger.Enabled(ctx, slog.LevelDebug) {
 		if fc.request == nil {