The BLS API: Synchronous and Asynchronous Test Results

I am a big fan of using APIs to pull data.  I am the creator of the R package blsAPI found on CRAN and GitHub.  As I mentioned in my previous post, I have started playing around with Python’s asyncio library.  I decided to try it out on the BLS’s API.

I set up a little test where I would request unemployment data (i.e. the number unemployed, the unemployment rate and the number in the labor force) for all 50 states and D.C. both synchronously and asynchronously.  The test was a bit of a hello world as it really didn’t do much more than request the data.  I just wanted to get a sense of the productivity gains.  My first run through all 153 requests took a little more than 2 seconds asynchronously and roughly 20 seconds synchronously.  That is a 10 fold difference!  That’s huge!

But before getting too excited I decided to run a few more tests to see if these results are typical.  Not wanting to adversely affect the BLS’s servers, I limited the number of runs to 100 each.  The test code is found at the end of this post for those interested in trying it out for themselves.

Here’s a screenshot of the test’s output to the console:

As you can see the results are pretty close to what I initially observed. The synchronous code took on average roughly 21.8 seconds to complete.  While the asynchronous took on average about 2.5 seconds.  Here’s a visualization of the full data set:

import requests
import json
import time
import asyncio
import pandas as pd

test_runs = 100

# BLS API Parameters
BLS_API_key = 'TYPE YOUR OWN KEY HERE'
headers = {'Content-type': 'application/json'}

BLS_LAUS_state_area_codes = ['ST0100000000000', 'ST0200000000000', 'ST0400000000000', 'ST0500000000000', 'ST0600000000000', 'ST0800000000000', 'ST0900000000000', 'ST1000000000000', 'ST1100000000000', 'ST1200000000000', 'ST1300000000000', 'ST1500000000000', 'ST1600000000000', 'ST1700000000000', 'ST1800000000000', 'ST1900000000000', 'ST2000000000000', 'ST2100000000000', 'ST2200000000000', 'ST2300000000000', 'ST2400000000000', 'ST2500000000000', 'ST2600000000000', 'ST2700000000000', 'ST2800000000000', 'ST2900000000000', 'ST3000000000000', 'ST3100000000000', 'ST3200000000000', 'ST3300000000000', 'ST3400000000000', 'ST3500000000000', 'ST3600000000000', 'ST3700000000000', 'ST3800000000000', 'ST3900000000000', 'ST4000000000000', 'ST4100000000000', 'ST4200000000000', 'ST4400000000000', 'ST4500000000000', 'ST4600000000000', 'ST4700000000000', 'ST4800000000000', 'ST4900000000000', 'ST5000000000000', 'ST5100000000000', 'ST5300000000000', 'ST5400000000000', 'ST5500000000000', 'ST5600000000000']
measures = ['03', '04', '05']

# Translate the area codes to series ids
seriesids = list()
for BLS_LAUS_state_area_code in BLS_LAUS_state_area_codes:
    for measure in measures:
        seriesids.append('LAS' + BLS_LAUS_state_area_code + measure)

number_of_requests = len(seriesids)


def fetch(seriesid):
    data = json.dumps({'seriesid': [seriesid], 'registrationkey': BLS_API_key})
    response = requests.post('https://api.bls.gov/publicAPI/v2/timeseries/data/', data=data, headers=headers)
    return response.json()

def async_fetch(seriesid):
    data = json.dumps({'seriesid': [seriesid], 'registrationkey': BLS_API_key})
    headers = {'Content-type': 'application/json'}
    response = requests.post('https://api.bls.gov/publicAPI/v2/timeseries/data/', data=data, headers=headers)
    return (seriesid, response.json())

async def fetch_all(seriesids):
    loop = asyncio.get_event_loop()
    futures = [
        loop.run_in_executor(
            None, 
            async_fetch, 
            seriesid
        )
        for seriesid in seriesids
    ]
    for d in await asyncio.gather(*futures):
        temp[d[0]] = d[1]
        
temp = dict()
results = dict()

for i in range(test_runs):
    test_run = i + 1

    # Test A - Synchronous Requests
    start_time = time.time()
    
    for seriesid in seriesids:
        temp[seriesid] = fetch(seriesid)
    
    synchronous_time = time.time() - start_time
    
    print("Test " + str(test_run) + "-A " + str(number_of_requests) + " Sychronous Requests: %s seconds" % (sychronous_time))
    
    # Test B - Asynchronous Requests
    start_time = time.time()
    
    loop = asyncio.get_event_loop()
    loop.run_until_complete(fetch_all(seriesids))
    
    asynchronous_time = time.time() - start_time
    
    print("Test " + str(test_run) + "-B " + str(number_of_requests) + " Asychronous Requests: %s seconds" % (asychronous_time))
    results[test_run] = {'Synchronous': synchronous_time, 'Asynchronous': aynchronous_time}

loop.close()
df = pd.DataFrame.from_dict(results, orient='index')
writer = pd.ExcelWriter('BLS Test.xlsx')
df.to_excel(writer,'Results')
writer.save()