dgkafka 1.0.2a1

Kafka clients

dgkafka

Python package for working with Apache Kafka supporting multiple data formats.

Installation

pip install dgkafka

For Avro support (requires additional dependencies):

pip install dgkafka[avro]

For Json support (requires additional dependencies):

pip install dgkafka[json]

Features

• Producers and consumers for different data formats:
  • Raw messages (bytes/strings)
  • JSON
  • Avro (with Schema Registry integration)
• Robust error handling
• Comprehensive operation logging
• Context manager support
• Flexible configuration

Quick Start

Basic Producer/Consumer

from dgkafka import KafkaProducer, KafkaConsumer

# Producer
with KafkaProducer(bootstrap_servers='localhost:9092') as producer:
    producer.produce('test_topic', 'Hello, Kafka!')

# Consumer
with KafkaConsumer(bootstrap_servers='localhost:9092', group_id='test_group') as consumer:
    consumer.subscribe(['test_topic'])
    for msg in consumer.consume():
        print(msg.value())

JSON Support

from dgkafka import JsonKafkaProducer, JsonKafkaConsumer

# Producer
with JsonKafkaProducer(bootstrap_servers='localhost:9092') as producer:
    producer.produce('json_topic', {'key': 'value'})

# Consumer
with JsonKafkaConsumer(bootstrap_servers='localhost:9092', group_id='json_group') as consumer:
    consumer.subscribe(['json_topic'])
    for msg in consumer.consume():
        print(msg.value())  # Automatically deserialized JSON

Avro Support

from dgkafka import AvroKafkaProducer, AvroKafkaConsumer

# Producer
value_schema = {
    "type": "record",
    "name": "User",
    "fields": [
        {"name": "name", "type": "string"},
        {"name": "age", "type": "int"}
    ]
}

with AvroKafkaProducer(
    schema_registry_url='http://localhost:8081',
    bootstrap_servers='localhost:9092',
    default_value_schema=value_schema
) as producer:
    producer.produce('avro_topic', {'name': 'Alice', 'age': 30})

# Consumer
with AvroKafkaConsumer(
    schema_registry_url='http://localhost:8081',
    bootstrap_servers='localhost:9092',
    group_id='avro_group'
) as consumer:
    consumer.subscribe(['avro_topic'])
    for msg in consumer.consume():
        print(msg.value())  # Automatically deserialized Avro object

Classes

Base Classes

• KafkaProducer - base message producer
• KafkaConsumer - base message consumer

Specialized Classes

• JsonKafkaProducer - JSON message producer (inherits from KafkaProducer)
• JsonKafkaConsumer - JSON message consumer (inherits from KafkaConsumer)
• AvroKafkaProducer - Avro message producer (inherits from KafkaProducer)
• AvroKafkaConsumer - Avro message consumer (inherits from KafkaConsumer)

Configuration

All classes accept standard Kafka configuration parameters:

config = {
    'bootstrap.servers': 'localhost:9092',
    'group.id': 'my_group',
    'auto.offset.reset': 'earliest'
}

Avro classes require additional parameter:

• schema_registry_url - Schema Registry URL

Logging

All classes use dglog.Logger for logging. You can provide a custom logger:

from dglog import Logger

logger = Logger()
producer = KafkaProducer(logger_=logger, ...)

Best Practices

1. Always use context managers (with) for proper resource cleanup
2. Implement error handling and retry logic for production use
3. Pre-register Avro schemas in Schema Registry
4. Configure appropriate acks and retries parameters for producers
5. Monitor consumer lag and producer throughput

Advanced Usage

Custom Serialization

# Custom Avro serializer
class CustomAvroProducer(AvroKafkaProducer):
    def _serialize_value(self, value):
        # Custom serialization logic
        return super()._serialize_value(value)

Message Headers

# Adding headers to messages
headers = {
    'correlation_id': '12345',
    'message_type': 'user_update'
}

producer.produce(
    topic='events',
    value=message_data,
    headers=headers
)

Error Handling

from confluent_kafka import KafkaException

try:
    with AvroKafkaProducer(...) as producer:
        producer.produce(...)
except KafkaException as e:
    print(f"Kafka error occurred: {e}")

Performance Tips

1. Batch messages when possible (batch.num.messages config)
2. Adjust linger.ms for better batching
3. Use compression.type (lz4, snappy, or gzip)
4. Tune fetch.max.bytes and max.partition.fetch.bytes for consumers

License

MIT