509 Bandwidth Limit Exceeded
HTTP response status code 509 Bandwidth Limit Exceeded is an unofficial server error that is specific to Apache Web Server and cPanel that indicates that the web hosting client has exceeded the bandwidth allotment on the server-side.
When the 509 Bandwidth Limit Exceeded status code is received, it means first that the web hosting client is using a connection or hosting method where the bandwidth is limited, for example due to a fixed monthly allotment as per the web hosting contract, and that the total bandwidth allocated has been exceeded.
When this error occurs, it may warrant an investigation as to why more data is being transferred than expected. This error on the server-side can be resolved by upgrading the data allotment with the web hosting provider. This error is often temporary until the allotment resets for the next period as per the web hosting contract, however no content is accessible to users during this period.
In the example, the HTTP client requests a resource using the HEAD method and the server responds with a 509 Bandwidth Limit Exceeded status code.
HEAD / HTTP/1.1
HTTP/1.1 509 Bandwidth Limit Exceeded
Content-Type: text/html; charset=UTF-8
The 509 Bandwidth Limit Exceeded status code is a server error used to indicate that the server has reached its bandwidth allowance on the server-side and consequently, the HTTP request of the HTTP client cannot be processed.