Data Cache

Simple in memory data cache designed for local non distributed ML applications. Built using Redis and Apache Arrow's Plasma in-memory store.

Installation

Install using pip: pip install git+https://github.com/jchacks/data_cache.git

Prerequisites

There are a few python packages that are required.

• Pyarrow
• Redis

Along with a running Redis server for the message queue.

Usage

Server

from data_cache import PlasmaServer

s = PlasmaServer(100000000) # 100MB
s.start()
s.wait()

# The location of the plasma store will be printed
# e.g. '/tmp/plasma-qd3yeugu/plasma.sock'
# This location is also added to the Redis store 
# so clients can automatically find it.

Data Producing Client

from data_cache import Client

# Ensure the `namespace` is the same everywhere the data is needed to be accessed
c = Client() 
q = c.make_queue('plasma', None)
# Put some dummy data into the queue
import numpy as np 

for i in range(10):
    r = q.put(np.ones((100000,)).astype('float32') * i)

Data Consuming Client

from data_cache import Client

c = Client()
q = c.make_queue('plasma', None) # Use the same name as above

# Fetch data off the queue using c.get()
import numpy as np 
d = np.stack([q.get() for i in range(10)])
print(d) 

# This will print the numpy array of 
# concatenated data in order 1->10

Setting persistant data on the store

import numpy as np 
from data_cache import Client

c = Client()
generic = c.get_or_create_store('generic')
generic['abc'] = np.ones((100000,)).astype('float32')

# This will access the data and not remove it from plasma
print(generic['abc'])