Add instrumentation for running Python SDK with profilers.

CHANGES.md

@@ -59,22 +59,21 @@
 
 ## Highlights
 
-* New highly anticipated feature X added to Python SDK ([#X](https://github.com/apache/beam/issues/X)).
-* New highly anticipated feature Y added to Java SDK ([#Y](https://github.com/apache/beam/issues/Y)).
+* Python SDK now supports memory profiling with Memray ([#38853](https://github.com/apache/beam/issues/38853)).
 * (Python) Added [Qdrant](https://qdrant.tech/) VectorDatabaseWriteConfig implementation ([#38141](https://github.com/apache/beam/issues/38141)).
 
+
 ## I/Os
 
 * Support for X source added (Java/Python) ([#X](https://github.com/apache/beam/issues/X)).
 
 ## New Features / Improvements
 
-* X feature added (Java/Python) ([#X](https://github.com/apache/beam/issues/X)).
 * (Java) Enabled state tag encoding v2 by default for new Dataflow Streaming Engine jobs. It can be disabled by passing `--experiments=disable_streaming_engine_state_tag_encoding_v2` or `--updateCompatibilityVersion=2.74.0` pipeline option. Note that the tag encoding version cannot change during a job update. Jobs using tag encoding v2 (enabled by default for new jobs on 2.75.0+) cannot be downgraded to Beam versions prior to 2.73.0, as only versions 2.73.0 and later support tag encoding v2. ([#38705](https://github.com/apache/beam/issues/38705)).
+* (Python) Added instrumentation to support off-the-shelf profiling agents when launching Python SDK Harness ([#38853](https://github.com/apache/beam/issues/38853)).
 
 ## Breaking Changes
 
-* X behavior was changed ([#X](https://github.com/apache/beam/issues/X)).
 * (Python) Typehints of dataclass fields are honored during type inferences. To restore the behavior of fallback-to-any,
   use pipeline option `--exclude_infer_dataclass_field_type` ([#38797](https://github.com/apache/beam/issues/38797)).
   However fixing forward is recommended.
@@ -85,7 +84,6 @@
 
 ## Bugfixes
 
-* Fixed X (Java/Python) ([#X](https://github.com/apache/beam/issues/X)).
 * Fixed IcebergIO writing manifest column bounds padded with trailing `0x00` bytes, which broke equality predicate pushdown in some query engines (Java) ([#38580](https://github.com/apache/beam/issues/38580)).
 
 ## Security Fixes

sdks/python/apache_beam/options/pipeline_options.py

@@ -1658,6 +1658,82 @@ def _add_argparse_args(cls, parser):
         default=1.0,
         help='A number between 0 and 1 indicating the ratio '
         'of bundles that should be profiled.')
+    parser.add_argument(
+        '--profiler_agent',
+        default=None,
+        help=(
+            'Specifies the profiling agent to launch the SDK worker harness '
+            'with (e.g., "memray", "tcmalloc", or a custom wrapper script/binary).'
+        ))
+    parser.add_argument(
+        '--profiler_extra_arg',
+        '--profiler_extra_args',
+        dest='profiler_extra_args',
+        action=_CommaSeparatedListAction,
+        default=None,
+        help=
+        'Comma-separated list of extra arguments to pass to the profiler agent.'
+    )
+    parser.add_argument(
+        '--profiler_extra_env_var',
+        '--profiler_extra_env_vars',
+        dest='profiler_extra_env_vars',
+        action=_CommaSeparatedListAction,
+        default=None,
+        help=(
+            'Comma-separated list of environment variables required by the profiler agent '
+            'in format "KEY1=VAL1,KEY2=VAL2".'))
+    parser.add_argument(
+        '--profile_temp_location',
+        default=None,
+        help=(
+            'Directory path on the worker where local profiles are saved. '
+            'Defaults to ${semi_persist_dir}/profiles if not specified.'))
+    parser.add_argument(
+        '--profile_upload_interval_sec',
+        type=int,
+        default=300,
+        help=(
+            'Frequency (in seconds) at which the local profiles are uploaded to GCS. '
+            'Defaults to 300 (5 min).'))
+    parser.add_argument(
+        '--profiler_stop_after_sec',
+        type=int,
+        default=0,
+        help=(
+            'Time limit (in seconds) for profiling a single process. When exceeded, '
+            'the worker process is restarted without the profiler.'))
+    parser.add_argument(
+        '--profiler_stop_after_crash',
+        action='store_true',
+        default=False,
+        help=(
+            'If True, the profiling agent won\'t be re-enabled after a worker '
+            'process crash.'))
+    parser.add_argument(
+        '--profile_postprocess_interval_sec',
+        type=int,
+        default=600,
+        help=(
+            'Frequency (in seconds) at which the local profiles are post-processed '
+            'on-the-fly. Defaults to 600 (10 minutes). Set to 0 to disable.'))
+
+  def validate(self, validator):
+    errors = []
+    if self.profiler_agent:
+      if self.profile_cpu or self.profile_memory:
+        errors.append(
+            '--profiler_agent is mutually exclusive with --profile_cpu '
+            'and --profile_memory.')
+
+      if not self.profile_location:
+        temp_location = self.view_as(GoogleCloudOptions).temp_location
+        if temp_location:
+          self.profile_location = temp_location.rstrip('/') + '/profiles'
+          _LOGGER.info(
+              'Setting --profile_location to %s since profiling is enabled.',
+              self.profile_location)
+    return errors
 
 
 class SetupOptions(PipelineOptions):

sdks/python/apache_beam/options/pipeline_options_test.py

@@ -669,6 +669,43 @@ def test_unknown_option_prefix(self):
       options = PipelineOptions(['--type_check_strictness', 'blahblah'])
       options.view_as(TypeOptions)
 
+  def test_profiling_agent_is_exclusive_with_legacy_profiling_options(self):
+    options = PipelineOptions(['--profiler_agent=memray'])
+    validator = PipelineOptionsValidator(options, None)
+    self.assertEqual(validator.validate(), [])
+
+    options = PipelineOptions(['--profiler_agent=memray', '--profile_cpu'])
+    validator = PipelineOptionsValidator(options, None)
+    errors = validator.validate()
+    self.assertTrue(
+        any('--profiler_agent is mutually exclusive' in err for err in errors))
+
+    options = PipelineOptions(['--profiler_agent=memray', '--profile_memory'])
+    validator = PipelineOptionsValidator(options, None)
+    errors = validator.validate()
+    self.assertTrue(
+        any('--profiler_agent is mutually exclusive' in err for err in errors))
+
+  def test_profile_location_defaulting_and_opt_out(self):
+    options = PipelineOptions(
+        ['--profiler_agent=memray', '--temp_location=gs://bucket/temp'])
+    validator = PipelineOptionsValidator(options, None)
+    self.assertEqual(validator.validate(), [])
+    self.assertEqual(
+        options.view_as(ProfilingOptions).profile_location,
+        'gs://bucket/temp/profiles')
+
+    options = PipelineOptions([
+        '--profiler_agent=memray',
+        '--temp_location=gs://bucket/temp',
+        '--profile_location=gs://other-bucket/custom_profiles'
+    ])
+    validator = PipelineOptionsValidator(options, None)
+    self.assertEqual(validator.validate(), [])
+    self.assertEqual(
+        options.view_as(ProfilingOptions).profile_location,
+        'gs://other-bucket/custom_profiles')
+
   def test_add_experiment(self):
     options = PipelineOptions([])
     options.view_as(DebugOptions).add_experiment('new_experiment')

sdks/python/apache_beam/options/pipeline_options_validator.py

@@ -30,6 +30,7 @@
 from apache_beam.options.pipeline_options import DebugOptions
 from apache_beam.options.pipeline_options import GoogleCloudOptions
 from apache_beam.options.pipeline_options import PortableOptions
+from apache_beam.options.pipeline_options import ProfilingOptions
 from apache_beam.options.pipeline_options import SetupOptions
 from apache_beam.options.pipeline_options import StandardOptions
 from apache_beam.options.pipeline_options import TestOptions
@@ -55,6 +56,7 @@ class PipelineOptionsValidator(object):
       DebugOptions,
       GoogleCloudOptions,
       PortableOptions,
+      ProfilingOptions,
       SetupOptions,
       StandardOptions,
       TestOptions,

sdks/python/container/Dockerfile

@@ -45,7 +45,10 @@ RUN  \
        ccache \
        # Required for using Beam Python SDK on ARM machines.
        libgeos-dev \
+       # Required for memory profiling with tcmalloc.
+       google-perftools \
        && \
+
     rm -rf /var/lib/apt/lists/* && \
 
     pip install --upgrade pip setuptools wheel && \

sdks/python/container/base_image_requirements_manual.txt

@@ -38,6 +38,8 @@ google-cloud-profiler;python_version<="3.12"
 # tests
 google-api-python-client;python_version<="3.13"
 guppy3
+# Explicitly pin memray to use a version compatible with postprocessing logic in Beam.
+memray==1.19.3
 mmh3  # Optimizes execution of some Beam codepaths. TODO: Make it Beam's dependency.
 nltk  # Commonly used for natural language processing.
 google-crc32c

sdks/python/container/boot.go

@@ -32,6 +32,7 @@ import (
 	"slices"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -133,7 +134,17 @@ type PipelineOptionsData struct {
 }
 
 type OptionsData struct {
-	Experiments []string `json:"experiments"`
+	Experiments                   []string `json:"experiments"`
+	ProfilerAgent                 string   `json:"profiler_agent"`
+	ProfilerExtraArgs             []string `json:"profiler_extra_args"`
+	ProfilerExtraEnvVars          []string `json:"profiler_extra_env_vars"`
+	ProfileLocation               string   `json:"profile_location"`
+	ProfileTempLocation           string   `json:"profile_temp_location"`
+	ProfileUploadIntervalSec      int      `json:"profile_upload_interval_sec"`
+	ProfilerStopAfterSec          int      `json:"profiler_stop_after_sec"`
+	ProfilerStopAfterCrash        bool     `json:"profiler_stop_after_crash"`
+	ProfilePostprocessIntervalSec int      `json:"profile_postprocess_interval_sec"`
+	JobId                         string   `json:"jobId,omitempty"`
 }
 
 func getExperiments(options string) []string {
@@ -198,6 +209,14 @@ func launchSDKProcess() error {
 		logger.Printf(ctx, "Build isolation disabled when installing packages with pip")
 	}
 
+	var opts PipelineOptionsData
+	if err := json.Unmarshal([]byte(options), &opts); err != nil {
+		logger.Warnf(ctx, "Failed to unmarshal pipeline options for profiling config: %v", err)
+	}
+
+	ctx = setupProfilerConfig(ctx, logger, &opts)
+	startProfilerBackgroundTasks(ctx, logger)
+
 	// (2) Retrieve and install the staged packages.
 	//
 	// No log.Fatalf() from here on, otherwise deferred cleanups will not be called!
@@ -314,11 +333,6 @@ func launchSDKProcess() error {
 		childPids.mu.Unlock()
 	}()
 
-	args := []string{
-		"-m",
-		sdkHarnessEntrypoint,
-	}
-
 	var wg sync.WaitGroup
 	wg.Add(len(workerIds))
 	for _, workerId := range workerIds {
@@ -333,12 +347,68 @@ func launchSDKProcess() error {
 					childPids.mu.Unlock()
 					return
 				}
-				logger.Printf(ctx, "Executing Python (worker %v): python %v", workerId, strings.Join(args, " "))
-				cmd := StartCommandEnv(map[string]string{"WORKER_ID": workerId}, os.Stdin, bufLogger, bufLogger, "python", args...)
+
+				currentProg := "python"
+				currentArgs := []string{"-m", sdkHarnessEntrypoint}
+				currentEnv := map[string]string{"WORKER_ID": workerId}
+
+				profilingActive := false
+				currentProg, currentArgs, currentEnv, profilingActive = maybeWithProfiler(
+					ctx, logger, workerId, currentProg, currentArgs, currentEnv,
+				)
+
+				var envStr string
+				if len(currentEnv) > 0 {
+					var envStrings []string
+					for k, v := range currentEnv {
+						envStrings = append(envStrings, k+"="+v)
+					}
+					slices.Sort(envStrings)
+					envStr = strings.Join(envStrings, ", ")
+				}
+
+				logger.Printf(ctx, "Executing Python (%v): %v %v", envStr, currentProg, strings.Join(currentArgs, " "))
+				cmd := StartCommandEnv(currentEnv, os.Stdin, bufLogger, bufLogger, currentProg, currentArgs...)
 				childPids.v = append(childPids.v, cmd.Process.Pid)
 				childPids.mu.Unlock()
 
-				if err := cmd.Wait(); err != nil {
+				var timer *time.Timer
+				var profilingTimedOut atomic.Bool
+
+				pcfg := getProfilerConfig(ctx)
+				if profilingActive && pcfg.StopAfterSec > 0 {
+					duration := time.Duration(pcfg.StopAfterSec) * time.Second
+					timer = time.AfterFunc(duration, func() {
+						childPids.mu.Lock()
+						defer childPids.mu.Unlock()
+						if cmd.Process != nil {
+							logger.Printf(ctx, "Profiling timeout of %d seconds reached. Sending SIGINT to worker %s",
+								pcfg.StopAfterSec, workerId)
+							profilingTimedOut.Store(true)
+							syscall.Kill(-cmd.Process.Pid, syscall.SIGINT)
+						}
+					})
+				}
+
+				err := cmd.Wait()
+				if timer != nil {
+					timer.Stop()
+				}
+
+				if err != nil {
+					if profilingTimedOut.Load() {
+						stopProfiling(ctx)
+						bufLogger.FlushAtDebug(ctx)
+						logger.Printf(ctx, "Python worker %v terminated after profiling timeout. Restarting without profiler.", workerId)
+						// Error is not counted toward error budget.
+						continue
+					}
+
+					if profilingActive && pcfg.StopAfterCrash {
+						stopProfiling(ctx)
+						logger.Printf(ctx, "Python worker %v crashed. Disabling profiler on subsequent restarts because --profiler_stop_after_crash is enabled.", workerId)
+					}
+
 					// Retry on fatal errors, like OOMs and segfaults, not just
 					// DoFns throwing exceptions.
 					errorCount += 1
@@ -532,3 +602,5 @@ func logSubmissionEnvDependencies(ctx context.Context, bufLogger *tools.Buffered
 	bufLogger.Printf(ctx, "%s", string(content))
 	return nil
 }
+
+