kcpy 0.1.6

A kinesis consumer is purely written in python.

Kinesis Consumer in Python

A kinesis consumer is purely written in python. This is a lightweight wrapper on top of AWS python library boto3. You also can consume records from Kinesis Data Stream (KDS) via:

• Lambda function: I have a demo kinesis-lambda-sqs-demo showing how to consume records in a serverless and real-time way.
• Kinesis Firehose: This is a AWS managed service and easily save records into different sinks, like S3, ElasticSearch, Redshift.

Installation

Install the package via pip:

pip install kcpy

Getting started

from kcpy import StreamConsumer
consumer = StreamConsumer('my_stream_name')
for record in consumer:
    print(record)

The output would look like:

{
    'ApproximateArrivalTimestamp': datetime.datetime(2018, 11, 13, 11, 57, 55, 117807), 
    'Data': b'Jessica Walter', 
    'PartitionKey': 'Jessica Walter', 
    'SequenceNumber': '1'
}

Or, you can consume stream data with checkpointing:

from kcpy import StreamConsumer
consumer = StreamConsumer('my_stream_name', consumer_name='my_consumer', checkpoint=True)
for record in consumer:
    print(record)

Checkpointing

Below shows the schema of checkpointing:

                                                                   producer
[stream_1]                                                            |
+---------------+---+---+---+---+---+---+---+---+                     |
| shard_1       | 1 | 2 | 3 | 4 | 5 | 6 | 7 |...| <-------------------+
+---------------+---+---+---+---+---+---+---+---+                     |
| shard_2       | 1 | 2 | 3 | 4 | 5 |...| <---------------------------+
+---------------+---+---+---+---+---+---+---+---+---+                 |
| shard_3       | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |...| <---------------+
+---------------+---+---+---+---+---+---+---+---+---+
                          ^                   ^
                          |                   |
                      consumer_1          consumer_2
                          |                   |
                          |                   +---------+
                          |                             |
                          +------------------+          |
                                             |          |
                                             v          |
+---------------+-------------+----------+--------+     |
| consumer_name | stream_name | shard_id | seq_no |     |
+---------------+-------------+----------+--------+     |
| consumer_1    | stream_1    | shard_1  |   5    |     |
| consumer_1    | stream_1    | shard_2  |   15   |     |
| consumer_1    | stream_1    | ...      |   15   |     |
| consumer_1    | stream_1    | shard_N  |   XX   |     |
| consumer_2    | stream_1    | shard_1  |   6    | <---+
+---------------+-------------+----------+--------+

Features

• Read records from a stream with multiple shards
• Save checkpoint for each shard consumer for a stream

Todo

• Add type checking with mypy
• Add the config for travis CI
• Add code coverage check
• Support other storage solutions (mysql, dynamodb, redis, etc.) for checkpointing
• Rebalance when the number of shards changes
• Allow kcpy to run on multiple machines

Changelog

0.1.5

• Add consumer checkpointing with a simple sqlite storage solution.

0.1.4

• Pass aws configurations into boto3 client directly.

0.1.3

• Update the README.

0.1.2

• Add markdown support for long description.

0.1.1

• Add a long description.

0.1.0

• First version of kcpy.

License

Copyright (c) 2018 Hengfeng Li. It is free software, and may be redistributed under the terms specified in the LICENSE file.