Concurrency Limiting

There are maximum limits for concurrent export requests. Tenable.io applies these limits on concurrent exports to ensure that all customers experience the same level of service. You can have a maximum of two or three active concurrent export requests per Tenable.io customer instance or container depending on which endpoint you are using.

Additionally, there is a maximum limit for concurrent scan launch requests. Tenable.io applies this limit on scan launches to prevent a single customer from draining cloud resources. You can have a maximum of 25 active scans per Tenable.io customer instance or container.

If you submit an API request after you reach the concurrency limit, Tenable.io returns an HTTP response message with a 429 (Too Many Requests) status code. The response also includes a retry-after header element that specifies the number of seconds to wait before retrying.

Example Response Header

connection:keep-alive 
content-length:580 
content-type:text/html
date:Wed, 24 Oct 2018 17:13:43 GMT 
retry-after:30 
server:tenable.io
strict-transport-security:max-age=63072000; includeSubDomains
x-content-type-options:nosniff
x-gateway-site-id:nginx-router-b-eng-us-east-1.dcld
x-path-handler:tenable-io-plugins-plugin

Concurrent Export Limits

The following table outlines the concurrency limits for specific Tenable.io export endpoints.

LimitAffected Endpoints
Two concurrent exports per container. Tenable.io also prevents duplicate exports from running concurrently. For example, export requests with the same filters.
Three concurrent requests per Tenable.io customer instance.

Note: This limit is subject to change.

Concurrent Active Scan Limits

The following table outlines the concurrency limit for active scans in Tenable.io.

LimitAffected Endpoint
25 active scans per container.

Note: To get the count of active scans in your container, use the Get scan count endpoint with the query parameter active set to true.