trustgraph/docs/tech-specs/import-export-graceful-shutdown.sw.md

---
layout: default
title: "Vipimo vya Kiufundi vya Uanzishaji na Kukomesha Kazi kwa Ufasaha (Import/Export)"
parent: "Swahili (Beta)"
---

# Vipimo vya Kiufundi vya Uanzishaji na Kukomesha Kazi kwa Ufasaha (Import/Export)

> **Beta Translation:** This document was translated via Machine Learning and as such may not be 100% accurate. All non-English languages are currently classified as Beta.

## Tatizo

Hivi sasa, mlango wa TrustGraph unapoteza ujumbe wakati wa kufunga muunganisho wa websocket katika operesheni za uanzishaji na kukomesha kazi. Hii hutokea kwa sababu ya migogoro ambapo ujumbe unaendelea hutupwa kabla ya kufika kwa lengo lake (mifereji ya Pulsar kwa uanzishaji, wateja wa websocket kwa kukomesha kazi).

### Masuala ya Upande wa Uanzishaji
1. Picha ya folyo ya `asyncio.Queue` ya mchapishaji haijafunguliwa wakati wa kukomesha kazi.
2. Websocket hufungwa kabla ya kuhakikisha kwamba ujumbe uliopangwa kufika kwenye Pulsar.
<<<<<<< HEAD
3. Hakuna mfumo wa uthibitisho wa uwasilishaji wa ujumbe kwa mafanikio.

### Masuala ya Upande wa Kukomesha Kazi
1. Ujumbe unaidhinishwa katika Pulsar kabla ya uwasilishaji wa mafanikio kwa wateja.
2. Muda uliopangwa (timeouts) husababisha kupotea kwa ujumbe wakati mifereji imejaa.
3. Hakuna mfumo wa kudhibiti kasi (backpressure) wa kushughulikia watumiaji (consumers) ambao ni polepole.
=======
3. Hakuna mfumo wa utambuzi kwa uwasilishaji wa ujumbe unaofanikiwa.

### Masuala ya Upande wa Kukomesha Kazi
1. Ujumbe hutambuliwa katika Pulsar kabla ya uwasilishaji wa mafanikio kwa wateja.
2. Muda uliopangwa (timeouts) husababisha kupotea kwa ujumbe wakati mifereji imejaa.
3. Hakuna mfumo wa kudhibiti kasi (backpressure) kwa kushughulikia watumiaji (consumers) ambao ni polepole.
>>>>>>> 82edf2d (New md files from RunPod)
4. Vituo vingi vya kuhifadhi ambapo data inaweza kupotea.

## Muhtasari wa Muundo

```
Import Flow:
Client -> Websocket -> TriplesImport -> Publisher -> Pulsar Queue

Export Flow:
Pulsar Queue -> Subscriber -> TriplesExport -> Websocket -> Client
```

## Marekebisho Yanayopendekezwa

### 1. Maboresho ya Mchapishaji (Upande wa Uingizaji)

#### A. Kusafisha Kina Kesi ya Mfululizo

**Faili**: `trustgraph-base/trustgraph/base/publisher.py`

```python
class Publisher:
    def __init__(self, client, topic, schema=None, max_size=10,
                 chunking_enabled=True, drain_timeout=5.0):
        self.client = client
        self.topic = topic
        self.schema = schema
        self.q = asyncio.Queue(maxsize=max_size)
        self.chunking_enabled = chunking_enabled
        self.running = True
        self.draining = False  # New state for graceful shutdown
        self.task = None
        self.drain_timeout = drain_timeout

    async def stop(self):
        """Initiate graceful shutdown with draining"""
        self.running = False
        self.draining = True
        
        if self.task:
            # Wait for run() to complete draining
            await self.task

    async def run(self):
        """Enhanced run method with integrated draining logic"""
        while self.running or self.draining:
            try:
                producer = self.client.create_producer(
                    topic=self.topic,
                    schema=JsonSchema(self.schema),
                    chunking_enabled=self.chunking_enabled,
                )

                drain_end_time = None
                
                while self.running or self.draining:
                    try:
                        # Start drain timeout when entering drain mode
                        if self.draining and drain_end_time is None:
                            drain_end_time = time.time() + self.drain_timeout
                            logger.info(f"Publisher entering drain mode, timeout={self.drain_timeout}s")
                        
                        # Check drain timeout
                        if self.draining and time.time() > drain_end_time:
                            if not self.q.empty():
                                logger.warning(f"Drain timeout reached with {self.q.qsize()} messages remaining")
                            self.draining = False
                            break
                        
                        # Calculate wait timeout based on mode
                        if self.draining:
                            # Shorter timeout during draining to exit quickly when empty
                            timeout = min(0.1, drain_end_time - time.time())
                        else:
                            # Normal operation timeout
                            timeout = 0.25
                        
                        # Get message from queue
                        id, item = await asyncio.wait_for(
                            self.q.get(),
                            timeout=timeout
                        )
                        
                        # Send the message (single place for sending)
                        if id:
                            producer.send(item, { "id": id })
                        else:
                            producer.send(item)
                            
                    except asyncio.TimeoutError:
                        # If draining and queue is empty, we're done
                        if self.draining and self.q.empty():
                            logger.info("Publisher queue drained successfully")
                            self.draining = False
                            break
                        continue
                        
                    except asyncio.QueueEmpty:
                        # If draining and queue is empty, we're done  
                        if self.draining and self.q.empty():
                            logger.info("Publisher queue drained successfully")
                            self.draining = False
                            break
                        continue
                
                # Flush producer before closing
                if producer:
                    producer.flush()
                    producer.close()

            except Exception as e:
                logger.error(f"Exception in publisher: {e}", exc_info=True)

            if not self.running and not self.draining:
                return

            # If handler drops out, sleep a retry
            await asyncio.sleep(1)

    async def send(self, id, item):
        """Send still works normally - just adds to queue"""
        if self.draining:
            # Optionally reject new messages during drain
            raise RuntimeError("Publisher is shutting down, not accepting new messages")
        await self.q.put((id, item))
```

**Manufaa Muhimu ya Ubunifu:**
**Eneo Moja la Kutuma:** Wito wote wa `producer.send()` hutokea katika sehemu moja ndani ya mbinu ya `run()`.
<<<<<<< HEAD
**Mashine ya Hali Safi:** Hali tatu wazi - inafanya kazi, inatakatishwa, imesimama.
**Ulinzi wa Muda:** Haingii katika hali ya kukwama kwa muda usio na kikomo wakati wa utaratibu wa utakatishaji.
**Ufuatiliaji Bora:** Uandikaji wazi wa maendeleo ya utaratibu wa utakatishaji na mabadiliko ya hali.
**Kukataa kwa Ujumbe (Hiari):** Inaweza kukataa ujumbe mpya wakati wa awamu ya kuzima.
=======
**Mashine ya Hali Safi:** Hali tatu wazi - inafanya kazi, inachosha, imesimama.
**Ulinzi wa Muda:** Haitemei kwa muda usio na kikomo wakati wa kuchosha.
**Ufuatiliaji Bora:** Uandikaji wazi wa maendeleo ya kuchosha na mabadiliko ya hali.
**Kukataa Ujumbe wa Hiari:** Inaweza kukataa ujumbe mpya wakati wa awamu ya kuzima.
>>>>>>> 82edf2d (New md files from RunPod)

#### B. Mpangilio Ulioboreshwa wa Kuzima

**Faili:** `trustgraph-flow/trustgraph/gateway/dispatch/triples_import.py`

```python
class TriplesImport:
    async def destroy(self):
        """Enhanced destroy with proper shutdown order"""
        # Step 1: Stop accepting new messages
        self.running.stop()
        
        # Step 2: Wait for publisher to drain its queue
        logger.info("Draining publisher queue...")
        await self.publisher.stop()
        
        # Step 3: Close websocket only after queue is drained
        if self.ws:
            await self.ws.close()
```

### 2. Maboresho kwa Wateja (Upande wa Uhamisho)

#### A. Mfumo Uliounganishwa wa Utoaji

**Faili**: `trustgraph-base/trustgraph/base/subscriber.py`

```python
class Subscriber:
    def __init__(self, client, topic, subscription, consumer_name,
                 schema=None, max_size=100, metrics=None,
                 backpressure_strategy="block", drain_timeout=5.0):
        # ... existing init ...
        self.backpressure_strategy = backpressure_strategy
        self.running = True
        self.draining = False  # New state for graceful shutdown
        self.drain_timeout = drain_timeout
        self.pending_acks = {}  # Track messages awaiting delivery
        
    async def stop(self):
        """Initiate graceful shutdown with draining"""
        self.running = False
        self.draining = True
        
        if self.task:
            # Wait for run() to complete draining
            await self.task
            
    async def run(self):
        """Enhanced run method with integrated draining logic"""
        while self.running or self.draining:
            if self.metrics:
                self.metrics.state("stopped")

            try:
                self.consumer = self.client.subscribe(
                    topic = self.topic,
                    subscription_name = self.subscription,
                    consumer_name = self.consumer_name,
                    schema = JsonSchema(self.schema),
                )

                if self.metrics:
                    self.metrics.state("running")

                logger.info("Subscriber running...")
                drain_end_time = None

                while self.running or self.draining:
                    # Start drain timeout when entering drain mode
                    if self.draining and drain_end_time is None:
                        drain_end_time = time.time() + self.drain_timeout
                        logger.info(f"Subscriber entering drain mode, timeout={self.drain_timeout}s")
                        
                        # Stop accepting new messages from Pulsar during drain
                        self.consumer.pause_message_listener()
                    
                    # Check drain timeout
                    if self.draining and time.time() > drain_end_time:
                        async with self.lock:
                            total_pending = sum(
                                q.qsize() for q in 
                                list(self.q.values()) + list(self.full.values())
                            )
                            if total_pending > 0:
                                logger.warning(f"Drain timeout reached with {total_pending} messages in queues")
                        self.draining = False
                        break
                    
                    # Check if we can exit drain mode
                    if self.draining:
                        async with self.lock:
                            all_empty = all(
                                q.empty() for q in 
                                list(self.q.values()) + list(self.full.values())
                            )
                            if all_empty and len(self.pending_acks) == 0:
                                logger.info("Subscriber queues drained successfully")
                                self.draining = False
                                break
                    
                    # Process messages only if not draining
                    if not self.draining:
                        try:
                            msg = await asyncio.to_thread(
                                self.consumer.receive,
                                timeout_millis=250
                            )
                        except _pulsar.Timeout:
                            continue
                        except Exception as e:
                            logger.error(f"Exception in subscriber receive: {e}", exc_info=True)
                            raise e

                        if self.metrics:
                            self.metrics.received()

                        # Process the message
                        await self._process_message(msg)
                    else:
                        # During draining, just wait for queues to empty
                        await asyncio.sleep(0.1)

            except Exception as e:
                logger.error(f"Subscriber exception: {e}", exc_info=True)

            finally:
                # Negative acknowledge any pending messages
                for msg in self.pending_acks.values():
                    self.consumer.negative_acknowledge(msg)
                self.pending_acks.clear()

                if self.consumer:
                    self.consumer.unsubscribe()
                    self.consumer.close()
                    self.consumer = None

            if self.metrics:
                self.metrics.state("stopped")

            if not self.running and not self.draining:
                return

            # If handler drops out, sleep a retry
            await asyncio.sleep(1)

    async def _process_message(self, msg):
        """Process a single message with deferred acknowledgment"""
        # Store message for later acknowledgment
        msg_id = str(uuid.uuid4())
        self.pending_acks[msg_id] = msg
        
        try:
            id = msg.properties()["id"]
        except:
            id = None
            
        value = msg.value()
        delivery_success = False
        
        async with self.lock:
            # Deliver to specific subscribers
            if id in self.q:
                delivery_success = await self._deliver_to_queue(
                    self.q[id], value
                )
            
            # Deliver to all subscribers
            for q in self.full.values():
                if await self._deliver_to_queue(q, value):
                    delivery_success = True
        
        # Acknowledge only on successful delivery
        if delivery_success:
            self.consumer.acknowledge(msg)
            del self.pending_acks[msg_id]
        else:
            # Negative acknowledge for retry
            self.consumer.negative_acknowledge(msg)
            del self.pending_acks[msg_id]
                
    async def _deliver_to_queue(self, queue, value):
        """Deliver message to queue with backpressure handling"""
        try:
            if self.backpressure_strategy == "block":
                # Block until space available (no timeout)
                await queue.put(value)
                return True
                
            elif self.backpressure_strategy == "drop_oldest":
                # Drop oldest message if queue full
                if queue.full():
                    try:
                        queue.get_nowait()
                        if self.metrics:
                            self.metrics.dropped()
                    except asyncio.QueueEmpty:
                        pass
                await queue.put(value)
                return True
                
            elif self.backpressure_strategy == "drop_new":
                # Drop new message if queue full
                if queue.full():
                    if self.metrics:
                        self.metrics.dropped()
                    return False
                await queue.put(value)
                return True
                
        except Exception as e:
            logger.error(f"Failed to deliver message: {e}")
            return False
```

**Manufaa Muhimu ya Ubunifu (kulingana na mtindo wa Mchapishaji):**
**Eneo Moja la Ufuatiliaji**: Ufuatiliaji wote wa ujumbe hutokea katika njia ya `run()`
<<<<<<< HEAD
**Mashine Safi ya Hali**: Hali tatu wazi - inafanya kazi, inachosha, imesimama
**Kusitisha Wakati wa Kuchosha**: Inasimamisha kupokea ujumbe mpya kutoka Pulsar wakati inachosha folyo zilizopo
**Ulinzi wa Muda**: Haingii katika hali ya kukwama kwa muda usio na kikomo wakati wa kuchosha
=======
**Mashine ya Hali Safi**: Hali tatu wazi - inafanya kazi, inatakatishwa, imesimama
**Kusitisha Wakati wa Kufyatua**: Inasimamisha kupokea ujumbe mpya kutoka Pulsar wakati wa kufyatua folyo zilizopo
**Ulinzi wa Muda**: Haingii katika hali ya kukamatwa kwa muda usio na kikomo wakati wa kufyatua
>>>>>>> 82edf2d (New md files from RunPod)
**Usafi Sawa**: Inatambua vibaya ujumbe wowote usiofikishwa wakati wa kuzima

#### B. Maboresho ya Kidhibiti cha Uhamisho

**Faili**: `trustgraph-flow/trustgraph/gateway/dispatch/triples_export.py`

```python
class TriplesExport:
    async def destroy(self):
        """Enhanced destroy with graceful shutdown"""
        # Step 1: Signal stop to prevent new messages
        self.running.stop()
        
        # Step 2: Wait briefly for in-flight messages
        await asyncio.sleep(0.5)
        
        # Step 3: Unsubscribe and stop subscriber (triggers queue drain)
        if hasattr(self, 'subs'):
            await self.subs.unsubscribe_all(self.id)
            await self.subs.stop()
        
        # Step 4: Close websocket last
        if self.ws and not self.ws.closed:
            await self.ws.close()
            
    async def run(self):
        """Enhanced run with better error handling"""
        self.subs = Subscriber(
            client = self.pulsar_client, 
            topic = self.queue,
            consumer_name = self.consumer, 
            subscription = self.subscriber,
            schema = Triples,
            backpressure_strategy = "block"  # Configurable
        )
        
        await self.subs.start()
        
        self.id = str(uuid.uuid4())
        q = await self.subs.subscribe_all(self.id)
        
        consecutive_errors = 0
        max_consecutive_errors = 5
        
        while self.running.get():
            try:
                resp = await asyncio.wait_for(q.get(), timeout=0.5)
                await self.ws.send_json(serialize_triples(resp))
                consecutive_errors = 0  # Reset on success
                
            except asyncio.TimeoutError:
                continue
                
            except queue.Empty:
                continue
                
            except Exception as e:
                logger.error(f"Exception sending to websocket: {str(e)}")
                consecutive_errors += 1
                
                if consecutive_errors >= max_consecutive_errors:
                    logger.error("Too many consecutive errors, shutting down")
                    break
                    
                # Brief pause before retry
                await asyncio.sleep(0.1)
        
        # Graceful cleanup handled in destroy()
```

### 3. Maboresho ya Kawaida ya Soketi

**Faili**: `trustgraph-flow/trustgraph/gateway/endpoint/socket.py`

```python
class SocketEndpoint:
    async def listener(self, ws, dispatcher, running):
        """Enhanced listener with graceful shutdown"""
        async for msg in ws:
            if msg.type == WSMsgType.TEXT:
                await dispatcher.receive(msg)
                continue
            elif msg.type == WSMsgType.BINARY:
                await dispatcher.receive(msg)
                continue
            else:
                # Graceful shutdown on close
                logger.info("Websocket closing, initiating graceful shutdown")
                running.stop()
                
                # Allow time for dispatcher cleanup
                await asyncio.sleep(1.0)
                break
                
    async def handle(self, request):
        """Enhanced handler with better cleanup"""
        # ... existing setup code ...
        
        try:
            async with asyncio.TaskGroup() as tg:
                running = Running()
                
                dispatcher = await self.dispatcher(
                    ws, running, request.match_info
                )
                
                worker_task = tg.create_task(
                    self.worker(ws, dispatcher, running)
                )
                
                lsnr_task = tg.create_task(
                    self.listener(ws, dispatcher, running)
                )
                
        except ExceptionGroup as e:
            logger.error("Exception group occurred:", exc_info=True)
            
            # Attempt graceful dispatcher shutdown
            try:
                await asyncio.wait_for(
                    dispatcher.destroy(), 
                    timeout=5.0
                )
            except asyncio.TimeoutError:
                logger.warning("Dispatcher shutdown timed out")
            except Exception as de:
                logger.error(f"Error during dispatcher cleanup: {de}")
                
        except Exception as e:
            logger.error(f"Socket exception: {e}", exc_info=True)
            
        finally:
            # Ensure dispatcher cleanup
            if dispatcher and hasattr(dispatcher, 'destroy'):
                try:
                    await dispatcher.destroy()
                except:
                    pass
                    
            # Ensure websocket is closed
            if ws and not ws.closed:
                await ws.close()
                
        return ws
```

## Chaguo za Usanidi

Ongeza usaidizi wa usanidi ili kurekebisha tabia:

```python
# config.py
class GracefulShutdownConfig:
    # Publisher settings
    PUBLISHER_DRAIN_TIMEOUT = 5.0  # Seconds to wait for queue drain
    PUBLISHER_FLUSH_TIMEOUT = 2.0  # Producer flush timeout
    
    # Subscriber settings  
    SUBSCRIBER_DRAIN_TIMEOUT = 5.0  # Seconds to wait for queue drain
    BACKPRESSURE_STRATEGY = "block"  # Options: "block", "drop_oldest", "drop_new"
    SUBSCRIBER_MAX_QUEUE_SIZE = 100  # Maximum queue size before backpressure
    
    # Socket settings
    SHUTDOWN_GRACE_PERIOD = 1.0  # Seconds to wait for graceful shutdown
    MAX_CONSECUTIVE_ERRORS = 5  # Maximum errors before forced shutdown
    
    # Monitoring
    LOG_QUEUE_STATS = True  # Log queue statistics on shutdown
    METRICS_ENABLED = True  # Enable metrics collection
```

## Mkakati wa Majaribio

### Majaribio ya Kitengo

```python
async def test_publisher_queue_drain():
    """Verify Publisher drains queue on shutdown"""
    publisher = Publisher(...)
    
    # Fill queue with messages
    for i in range(10):
        await publisher.send(f"id-{i}", {"data": i})
    
    # Stop publisher
    await publisher.stop()
    
    # Verify all messages were sent
    assert publisher.q.empty()
    assert mock_producer.send.call_count == 10

async def test_subscriber_deferred_ack():
    """Verify Subscriber only acks on successful delivery"""
    subscriber = Subscriber(..., backpressure_strategy="drop_new")
    
    # Fill queue to capacity
    queue = await subscriber.subscribe("test")
    for i in range(100):
        await queue.put({"data": i})
    
    # Try to add message when full
    msg = create_mock_message()
    await subscriber._process_message(msg)
    
    # Verify negative acknowledgment
    assert msg.negative_acknowledge.called
    assert not msg.acknowledge.called
```

### Majaribio ya Uunganishaji

```python
async def test_import_graceful_shutdown():
    """Test import path handles shutdown gracefully"""
    # Setup
    import_handler = TriplesImport(...)
    await import_handler.start()
    
    # Send messages
    messages = []
    for i in range(100):
        msg = {"metadata": {...}, "triples": [...]}
        await import_handler.receive(msg)
        messages.append(msg)
    
    # Shutdown while messages in flight
    await import_handler.destroy()
    
    # Verify all messages reached Pulsar
    received = await pulsar_consumer.receive_all()
    assert len(received) == 100

async def test_export_no_message_loss():
    """Test export path doesn't lose acknowledged messages"""
    # Setup Pulsar with test messages
    for i in range(100):
        await pulsar_producer.send({"data": i})
    
    # Start export handler
    export_handler = TriplesExport(...)
    export_task = asyncio.create_task(export_handler.run())
    
    # Receive some messages
    received = []
    for _ in range(50):
        msg = await websocket.receive()
        received.append(msg)
    
    # Force shutdown
    await export_handler.destroy()
    
    # Continue receiving until websocket closes
    while not websocket.closed:
        try:
            msg = await websocket.receive()
            received.append(msg)
        except:
            break
    
    # Verify no acknowledged messages were lost
    assert len(received) >= 50
```

<<<<<<< HEAD
## Mpango wa Utendaji
=======
## Mpango wa Utumizaji
>>>>>>> 82edf2d (New md files from RunPod)

### Awamu ya 1: Marekebisho Muhimu (Wiki ya 1)
Marekebisho ya muda wa utambuzi wa mshabiki (kuzuia upotevu wa ujumbe)
Ongeza utaratibu wa kusafisha folyo ya mchapishaji
<<<<<<< HEAD
Tuma kwenye mazingira ya majaribio

### Awamu ya 2: Kusitisha kwa Ufasaha (Wiki ya 2)
Lenga kusitisha kwa ufasaha
Ongeza mikakati ya shinikizo nyuma
=======
Toa toleo kwenye mazingira ya majaribio

### Awamu ya 2: Kusitisha kwa Ufasaha (Wiki ya 2)
Lenga utaratibu wa usitishaji
Ongeza mikakati ya kupunguza mzigo
>>>>>>> 82edf2d (New md files from RunPod)
Vipimo vya utendaji

### Awamu ya 3: Ufuatiliaji na Urekebishaji (Wiki ya 3)
Ongeza vipimo vya kina ya folyo
Ongeza arifa za upotevu wa ujumbe
Rekebisha maadili ya muda wa kusubiri kulingana na data ya uzalishaji

## Ufuatiliaji na Arifa

### Vipimo vya Kufuata
`publisher.queue.depth` - Ukubwa wa sasa wa folyo ya mchapishaji
`publisher.messages.dropped` - Ujumbe uliopotea wakati wa kusitisha
`subscriber.messages.negatively_acknowledged` - Utoaji ambao haujafanikiwa
<<<<<<< HEAD
`websocket.graceful_shutdowns` - Kusitisha kwa ufasaha ambavyo vimefanikiwa
`websocket.forced_shutdowns` - Kusitisha kwa nguvu/kwa muda mrefu
=======
`websocket.graceful_shutdowns` - Usitishaji wa ufasaha ambao umefanikiwa
`websocket.forced_shutdowns` - Usitishaji wa lazima/wa muda
>>>>>>> 82edf2d (New md files from RunPod)

### Arifa
Kina cha folyo ya mchapishaji > 80% ya uwezo
Upotevu wowote wa ujumbe wakati wa kusitisha
Kiwango cha kukataa cha mshabiki > 1%
<<<<<<< HEAD
Muda wa kusitisha umepita
=======
Muda wa kusitisha ambao umevuka
>>>>>>> 82edf2d (New md files from RunPod)

## Ulinganifu na Mifumo ya Zamani

Marekebisho yote yanahifadhi ulinganifu na mifumo ya zamani:
Tabia ya kawaida haibadiliki bila usanidi
Uwekaji wa sasa unaendelea kufanya kazi
Kupungua kwa utendaji ikiwa vipengele vipya havipatikani

## Masuala ya Usalama

Vipengele vipya vya mashambulizi haviongezwi
<<<<<<< HEAD
Shinikizo nyuma huzuia mashambulizi ya kutumia kumbukumbu nyingi
Mipaka inayoweza kusanidiwa huzuia matumizi mabaya ya rasilimali
=======
Kupunguza mzigo huzuia mashambulizi ya kutokwa na kumbukumbu
Mipaka inayoweza kusanidiwa inazuia unyonyaji wa rasilimali
>>>>>>> 82edf2d (New md files from RunPod)

## Athari za Utendaji

Uwezekano mdogo wakati wa operesheni ya kawaida
Kusitisha kunaweza kuchukua sekunde 5 zaidi (inaweza kusanidiwa)
Matumizi ya kumbukumbu yanapingika na mipaka ya ukubwa wa folyo
Athari ya CPU ni ndogo (<1% ya ongezeko)