Understand how ZenRows® concurrency works
Concurrency-Limit
: Indicates the total number of concurrent requests allowed by your current plan. This header helps you understand the maximum concurrency capacity available to you.Concurrency-Remaining
: Shows the number of available concurrency slots at the time the request was received by the server. This provides insight into how many slots are still free.Concurrency-Limit: 20
Concurrency-Remaining: 17
Concurrency-Remaining
header of the most recent response.Concurrency-Remaining
is 5, avoid sending more than 5 simultaneous requests.asyncio.gather
function will wait for all the calls to finish and store all the responses in an array. Afterward, you can loop over the array and extract the necessary data. Each response will include the status, request, response content, and other values. Remember to run the scripts with asyncio.run
to avoid a coroutine 'main' was never awaited
error.
requests
requests
library and want to handle multiple requests concurrently, Python’s multiprocessing package can be an effective solution. This approach is particularly useful when you’re dealing with a large list of URLs and need to speed up the data collection process by sending multiple requests simultaneously.
multiprocessing
package in Python includes a ThreadPool
class, which allows you to manage a pool of worker threads. Each thread can handle a separate task, enabling multiple HTTP requests to be processed in parallel. This is particularly beneficial when scraping data from a large number of websites, as it reduces the overall time required.
fulfilled
and rejected
responses separately, allowing you to log errors or retry failed requests as needed.
How does concurrency affect the speed of scraping tasks?
What happens if I exceed my concurrency limit?
429 Too Many Requests
error. The system won’t accept additional requests until current tasks complete and free up slots.How can I monitor my available concurrency slots?
Concurrency-Remaining
header in your API responses to check how many slots are still available for sending new requests.What is the difference between concurrency and rate limiting?
How can I handle slow requests and optimize concurrency usage?
If I cancel a request, will it free up the concurrency right away?