fix: reduce memory usage for monthly ZIP archive flow

Replace generated archive download response with FileResponse streaming so ZIP files are not fully loaded into process memory.

Move monthly archive task output to a temporary file and upload that file to storage, and write invoice attachments into ZIP archives in chunks.

Add Celery memory guard settings, a memory-aware base task hook, and periodic /tmp cleanup for prefixed archive files older than one day.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/core/celery.py

@@ -1,7 +1,12 @@
 # backend/core/celery.py
 
 import os
+import gc
+import logging
 from celery import Celery
+from celery import Task
+
+logger = logging.getLogger(__name__)
 
 # Postavi Django settings modul
 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'core.settings')
@@ -11,5 +16,42 @@ app = Celery('core')
 # Koristi konfiguraciju iz settings.py s prefiksom 'CELERY_'
 app.config_from_object('django.conf:settings', namespace='CELERY')
 
+
+def _rss_memory_mb():
+    try:
+        import resource
+
+        usage_kb = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
+        # Na Linuxu je ru_maxrss u KiB.
+        return round(float(usage_kb) / 1024.0, 2)
+    except (ImportError, AttributeError, OSError, ValueError):
+        return None
+
+
+class MemoryAwareTask(Task):
+    abstract = True
+
+    def __call__(self, *args, **kwargs):
+        gc.collect()
+        return super().__call__(*args, **kwargs)
+
+    def after_return(self, status, retval, task_id, args, kwargs, einfo):
+        memory_before_gc = _rss_memory_mb()
+        gc.collect()
+        memory_after_gc = _rss_memory_mb()
+        if memory_before_gc is not None and memory_after_gc is not None:
+            logger.info(
+                "Task %s (%s) status=%s RSS prije/poslije GC: %.2fMB -> %.2fMB",
+                self.name,
+                task_id,
+                status,
+                memory_before_gc,
+                memory_after_gc,
+            )
+        return super().after_return(status, retval, task_id, args, kwargs, einfo)
+
+
+app.Task = MemoryAwareTask
+
 # Automatski pronalazi taskove u svim 'modules.*'
 app.autodiscover_tasks()

backend/core/settings/base.py

@@ -154,6 +154,11 @@ REDIS_URL = os.environ.get('REDIS_URL', 'redis://localhost:6379/0')
 
 CELERY_BROKER_URL = REDIS_URL
 CELERY_RESULT_BACKEND = REDIS_URL
+CELERY_WORKER_PREFETCH_MULTIPLIER = int(os.environ.get('CELERY_WORKER_PREFETCH_MULTIPLIER', '1'))
+CELERY_WORKER_MAX_TASKS_PER_CHILD = int(os.environ.get('CELERY_WORKER_MAX_TASKS_PER_CHILD', '20'))
+CELERY_WORKER_MAX_MEMORY_PER_CHILD = int(os.environ.get('CELERY_WORKER_MAX_MEMORY_PER_CHILD', '350000'))
+CELERY_TASK_ACKS_LATE = True
+CELERY_TASK_REJECT_ON_WORKER_LOST = True
 
 # Ako želiš koristiti Redis kao brzi cache sustav unutar Djanga (izvrsno za ERP performanse)
 # Za ovo ti je potreban paket 'django-redis' u requirements.txt
@@ -171,10 +176,18 @@ CACHES = {
 CELERY_ACCEPT_CONTENT = ['json']
 CELERY_TASK_SERIALIZER = 'json'
 CELERY_BEAT_SCHEDULE = {
+    'cleanup-expired-generated-archives-hourly': {
+        'task': 'modules.fleet.tasks.cleanup_expired_generated_archives_task',
+        'schedule': crontab(minute=5),
+    },
     'cleanup-expired-generated-pdfs-hourly': {
         'task': 'modules.fleet.tasks.cleanup_expired_generated_pdfs_task',
         'schedule': crontab(minute=0),
     },
+    'cleanup-app-tmp-daily': {
+        'task': 'modules.fleet.tasks.cleanup_tmp_files_task',
+        'schedule': crontab(hour=3, minute=15),
+    },
     'notify-upcoming-tasks-daily': {
         'task': 'modules.task_management.tasks.notify_upcoming_tasks',
         'schedule': crontab(hour=8, minute=0),
@@ -190,6 +203,13 @@ STATIC_URL = '/static/'
 # (Opcionalno, ali preporučeno za ERP) Ako koristiš i medije (dokumente)
 MEDIA_URL = '/media/'
 MEDIA_ROOT = BASE_DIR / 'media'
+APP_TMP_CLEANUP_DIR = os.environ.get('APP_TMP_CLEANUP_DIR', '/tmp')
+APP_TMP_CLEANUP_MAX_AGE_HOURS = int(os.environ.get('APP_TMP_CLEANUP_MAX_AGE_HOURS', '24'))
+APP_TMP_CLEANUP_PREFIXES = [
+    prefix.strip()
+    for prefix in os.environ.get('APP_TMP_CLEANUP_PREFIXES', 'erp-fleet-archive-').split(',')
+    if prefix.strip()
+]
 
 
 # ==============================================================================

backend/modules/fleet/tasks.py

@@ -5,6 +5,7 @@ from django.core.mail import EmailMessage
 from django.conf import settings
 from django.utils import timezone
 from django.core.files.base import ContentFile
+from django.core.files import File
 import logging
 from io import BytesIO
 from io import StringIO
@@ -13,6 +14,9 @@ import base64
 import re
 import csv
 import mimetypes
+import os
+import tempfile
+import zipfile
 from decimal import Decimal, InvalidOperation
 from smtplib import SMTPSenderRefused
 from datetime import timedelta
@@ -838,10 +842,9 @@ def process_work_order_invoice_ocr(invoice_id):
 @shared_task
 def build_monthly_archive_cached_task(generated_archive_id):
     from .models import GeneratedFleetArchive
-    from .services import NotificationService
     from .views import (
-        _build_monthly_service_tasks_archive_content,
+        _write_monthly_service_tasks_archive_entries,
-        _build_monthly_work_orders_archive_content,
+        _write_monthly_work_orders_archive_entries,
         _notify_monthly_archive_request,
     )
 
@@ -854,25 +857,39 @@ def build_monthly_archive_cached_task(generated_archive_id):
     if generated is None:
         return {"status": "failed", "error": "Generated archive record not found"}
 
+    tmp_dir = str(getattr(settings, 'APP_TMP_CLEANUP_DIR', '/tmp'))
+    with tempfile.NamedTemporaryFile(
+        mode='w+b',
+        delete=False,
+        dir=tmp_dir if os.path.isdir(tmp_dir) else None,
+        prefix='erp-fleet-archive-',
+        suffix='.zip',
+    ) as temp_zip:
+        temp_zip_path = temp_zip.name
     try:
+        with zipfile.ZipFile(temp_zip_path, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
             if generated.archive_type == 'service_tasks':
-            archive_content = _build_monthly_service_tasks_archive_content(
+                entries_written = _write_monthly_service_tasks_archive_entries(
+                    archive,
                     user=generated.requested_by,
                     year=generated.year,
                     month=generated.month,
                 )
             else:
-            archive_content = _build_monthly_work_orders_archive_content(
+                entries_written = _write_monthly_work_orders_archive_entries(
+                    archive,
                     user=generated.requested_by,
                     year=generated.year,
                     month=generated.month,
                 )
-
+        if entries_written == 0:
-        if not archive_content:
             raise ValueError('ZIP arhiva je prazna.')
 
+        if os.path.getsize(temp_zip_path) <= 0:
+            raise ValueError('ZIP arhiva je prazna.')
         filename = generated.filename or f"{generated.archive_type}-{generated.year}-{generated.month}.zip"
-        generated.file.save(filename, ContentFile(archive_content), save=False)
+        with open(temp_zip_path, 'rb') as temp_file:
+            generated.file.save(filename, File(temp_file), save=False)
         generated.status = 'ready'
         generated.error_message = ''
         generated.save(update_fields=['file', 'status', 'error_message', 'updated_at'])
@@ -902,6 +919,12 @@ def build_monthly_archive_cached_task(generated_archive_id):
             )
         logger.exception("Greška kod build_monthly_archive_cached_task: %s", exc)
         return {"status": "failed", "error": str(exc)}
+    finally:
+        try:
+            if os.path.exists(temp_zip_path):
+                os.remove(temp_zip_path)
+        except OSError:
+            logger.warning("Ne mogu obrisati privremenu ZIP datoteku: %s", temp_zip_path)
 
 
 @shared_task
@@ -944,6 +967,46 @@ def cleanup_expired_generated_pdfs_task():
     return {"deleted": deleted}
 
 
+@shared_task
+def cleanup_tmp_files_task():
+    tmp_dir = str(getattr(settings, 'APP_TMP_CLEANUP_DIR', '/tmp'))
+    max_age_hours = int(getattr(settings, 'APP_TMP_CLEANUP_MAX_AGE_HOURS', 24))
+    prefixes = tuple(getattr(settings, 'APP_TMP_CLEANUP_PREFIXES', ['erp-fleet-archive-']))
+
+    if max_age_hours <= 0:
+        raise ValueError('APP_TMP_CLEANUP_MAX_AGE_HOURS mora biti > 0.')
+    if not prefixes:
+        raise ValueError('APP_TMP_CLEANUP_PREFIXES ne smije biti prazan.')
+    if not os.path.isdir(tmp_dir):
+        return {'deleted': 0, 'tmp_dir': tmp_dir, 'reason': 'tmp-dir-not-found'}
+
+    now = timezone.now().timestamp()
+    cutoff = now - (max_age_hours * 3600)
+    deleted = 0
+
+    for name in os.listdir(tmp_dir):
+        if not any(name.startswith(prefix) for prefix in prefixes):
+            continue
+        full_path = os.path.join(tmp_dir, name)
+        try:
+            stat_info = os.stat(full_path)
+        except FileNotFoundError:
+            continue
+        if stat_info.st_mtime > cutoff:
+            continue
+        if os.path.isdir(full_path):
+            try:
+                os.rmdir(full_path)
+            except OSError:
+                logger.warning("Preskačem %s: direktorij nije prazan ili je nedostupan.", full_path)
+                continue
+        else:
+            os.remove(full_path)
+        deleted += 1
+
+    return {'deleted': deleted, 'tmp_dir': tmp_dir, 'max_age_hours': max_age_hours}
+
+
 @shared_task
 def build_work_order_pdf_cached_task(generated_pdf_id):
     from .views import _build_work_order_pdf, _build_work_order_service_records_pdf

backend/modules/fleet/views.py

@@ -2450,6 +2450,26 @@ def _file_attachment(file_field, fallback_name):
     return (filename, content, _guess_content_type(filename))
 
 
+def _write_file_field_to_zip(archive, *, file_field, entry_name, chunk_size=64 * 1024):
+    if not file_field:
+        return False
+    file_field.open('rb')
+    try:
+        first_chunk = file_field.read(chunk_size)
+        if not first_chunk:
+            return False
+        with archive.open(entry_name, mode='w') as destination:
+            destination.write(first_chunk)
+            while True:
+                chunk = file_field.read(chunk_size)
+                if not chunk:
+                    break
+                destination.write(chunk)
+    finally:
+        file_field.close()
+    return True
+
+
 def _build_image_attachments_for_work_order(work_order):
     attachments = []
     photos = WorkOrderPhoto.objects.filter(is_active=True, work_order=work_order).order_by('created_at')
@@ -3008,7 +3028,7 @@ def _parse_year_month_params(request):
     return year, month
 
 
-def _build_monthly_service_tasks_archive_content(*, user, year, month):
+def _write_monthly_service_tasks_archive_entries(archive, *, user, year, month):
     from modules.task_management.models import Task
 
     tasks = list(
@@ -3028,8 +3048,7 @@ def _build_monthly_service_tasks_archive_content(*, user, year, month):
         raise DRFValidationError({'detail': 'Nema servisnih taskova za odabrani mjesec.'})
 
     used_names = set()
-    archive_buffer = BytesIO()
+    entries_written = 0
-    with zipfile.ZipFile(archive_buffer, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
     for task in tasks:
         work_order = task.work_order
         if work_order is None:
@@ -3038,14 +3057,28 @@ def _build_monthly_service_tasks_archive_content(*, user, year, month):
         base_name = _service_records_docx_filename(work_order, task)
         entry_name = _unique_zip_entry_name(base_name, used_names)
         archive.writestr(entry_name, docx_bytes)
+        entries_written += 1
+    if entries_written == 0:
+        raise DRFValidationError({'detail': 'Nije moguće kreirati ZIP za odabrani mjesec.'})
+    return entries_written
 
+
+def _build_monthly_service_tasks_archive_content(*, user, year, month):
+    archive_buffer = BytesIO()
+    with zipfile.ZipFile(archive_buffer, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
+        _write_monthly_service_tasks_archive_entries(
+            archive,
+            user=user,
+            year=year,
+            month=month,
+        )
     archive_content = archive_buffer.getvalue()
     if not archive_content:
         raise DRFValidationError({'detail': 'Nije moguće kreirati ZIP za odabrani mjesec.'})
     return archive_content
 
 
-def _build_monthly_work_orders_archive_content(*, user, year, month):
+def _write_monthly_work_orders_archive_entries(archive, *, user, year, month):
     from modules.task_management.models import Task
 
     monthly_tasks = (
@@ -3084,23 +3117,34 @@ def _build_monthly_work_orders_archive_content(*, user, year, month):
         raise DRFValidationError({'detail': 'Nema putnih naloga za odabrani mjesec.'})
 
     used_names = set()
-    archive_buffer = BytesIO()
+    entries_written = 0
-    with zipfile.ZipFile(archive_buffer, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
     for work_order in work_orders:
         pdf_bytes = _build_work_order_pdf(work_order)
         work_order_pdf_name = _unique_zip_entry_name(_pdf_filename(work_order, 'work_order'), used_names)
         archive.writestr(work_order_pdf_name, pdf_bytes)
+        entries_written += 1
 
         display_code = _work_order_display_code(work_order)
         invoices = work_order.invoices.filter(is_active=True).order_by('datum', 'created_at')
         for index, invoice in enumerate(invoices, start=1):
-                attachment = _file_attachment(invoice.image, fallback_name=f"invoice-{index}.bin")
+            file_name = Path(str(getattr(getattr(invoice, 'image', None), 'name', '') or f"invoice-{index}.bin")).name
-                if not attachment:
+            archive_path = _unique_zip_entry_name(f"Racuni/{display_code}/{file_name}", used_names)
-                    continue
+            if _write_file_field_to_zip(archive, file_field=invoice.image, entry_name=archive_path):
-                invoice_filename, content, _content_type = attachment
+                entries_written += 1
-                archive_path = f"Racuni/{display_code}/{invoice_filename}"
+    if entries_written == 0:
-                archive.writestr(_unique_zip_entry_name(archive_path, used_names), content)
+        raise DRFValidationError({'detail': 'Nije moguće kreirati ZIP za odabrani mjesec.'})
+    return entries_written
 
+
+def _build_monthly_work_orders_archive_content(*, user, year, month):
+    archive_buffer = BytesIO()
+    with zipfile.ZipFile(archive_buffer, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
+        _write_monthly_work_orders_archive_entries(
+            archive,
+            user=user,
+            year=year,
+            month=month,
+        )
     archive_content = archive_buffer.getvalue()
     if not archive_content:
         raise DRFValidationError({'detail': 'Nije moguće kreirati ZIP za odabrani mjesec.'})
@@ -3411,12 +3455,18 @@ def generated_archive_download(request, archive_id):
     if generated_archive is None:
         raise DRFValidationError({'detail': 'ZIP arhiva nije dostupna ili je istekla.'})
 
-    generated_archive.file.open('rb')
+    file_name = getattr(generated_archive.file, 'name', '')
+    storage = getattr(generated_archive.file, 'storage', None)
+    if not file_name or storage is None:
+        raise DRFValidationError({'detail': 'ZIP arhiva je prazna ili nedostupna.'})
     try:
-        archive_bytes = generated_archive.file.read()
+        if not storage.exists(file_name):
-    finally:
+            raise DRFValidationError({'detail': 'ZIP arhiva je prazna ili nedostupna.'})
-        generated_archive.file.close()
+    except (FileNotFoundError, OSError, ValueError):
-    if not archive_bytes:
+        raise DRFValidationError({'detail': 'ZIP arhiva je prazna ili nedostupna.'})
+    try:
+        generated_archive.file.open('rb')
+    except (FileNotFoundError, OSError, ValueError):
         raise DRFValidationError({'detail': 'ZIP arhiva je prazna ili nedostupna.'})
     filename = generated_archive.filename or _generated_archive_filename_for_user(
         request.user,
@@ -3424,10 +3474,13 @@ def generated_archive_download(request, archive_id):
         month=generated_archive.month,
         archive_type=generated_archive.archive_type,
     )
-    response = HttpResponse(archive_bytes, content_type='application/zip')
+    response = FileResponse(generated_archive.file, content_type='application/zip')
     response['Content-Disposition'] = f'attachment; filename="{filename}"'
     response['Cache-Control'] = 'private, max-age=3600'
-    response['Content-Length'] = str(len(archive_bytes))
+    try:
+        response['Content-Length'] = str(generated_archive.file.size)
+    except (OSError, ValueError, TypeError):
+        pass
     return response
 
 

backend/scripts/cleanup_tmp_files.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+set -eu
+
+TMP_DIR="${APP_TMP_CLEANUP_DIR:-/tmp}"
+MAX_AGE_DAYS="${APP_TMP_CLEANUP_MAX_AGE_DAYS:-1}"
+PREFIXES="${APP_TMP_CLEANUP_PREFIXES:-erp-fleet-archive-}"
+
+if [ ! -d "$TMP_DIR" ]; then
+  echo "TMP dir ne postoji: $TMP_DIR"
+  exit 0
+fi
+
+OLD_IFS="$IFS"
+IFS=','
+for prefix in $PREFIXES; do
+  prefix_trimmed="$(echo "$prefix" | xargs)"
+  if [ -z "$prefix_trimmed" ]; then
+    continue
+  fi
+  find "$TMP_DIR" -maxdepth 1 -mindepth 1 -name "${prefix_trimmed}*" -mtime "+${MAX_AGE_DAYS}" -print -delete
+done
+IFS="$OLD_IFS"
+
+echo "TMP cleanup dovršen za $TMP_DIR (older than ${MAX_AGE_DAYS} day(s))."

docker-compose.prod.yml

@@ -37,7 +37,13 @@ services:
     environment:
       DEBUG: "False"
       DJANGO_SETTINGS_MODULE: core.settings.production
-    command: celery -A core worker --loglevel=info
+      CELERY_WORKER_PREFETCH_MULTIPLIER: "1"
+      CELERY_WORKER_MAX_TASKS_PER_CHILD: "20"
+      CELERY_WORKER_MAX_MEMORY_PER_CHILD: "350000"
+      APP_TMP_CLEANUP_DIR: "/tmp"
+      APP_TMP_CLEANUP_MAX_AGE_HOURS: "24"
+      APP_TMP_CLEANUP_PREFIXES: "erp-fleet-archive-"
+    command: celery -A core worker --loglevel=info --concurrency=${CELERY_WORKER_CONCURRENCY:-2}
     volumes:
       - media_volume:/app/media
     depends_on: