upload_buffer_size
Sets the size of the buffer used for handling file uploads in NGINX.
Description
The upload_buffer_size directive in NGINX specifies the size of the buffer used for reading the uploaded file's data when handling file uploads via 'multipart/form-data'. This directive is part of the NGINX upload module, which supports uploading files and handling each file in the request separately. By adjusting the buffer size, you can optimize the upload process, especially for larger files, as it determines how much data is temporarily stored in memory before being written to disk or processed further.
When uploading files, the directive accepts an argument that defines the size of the buffer in bytes. This setting can be useful in contexts such as HTTP, server, or location blocks. A smaller buffer may lead to increased disk I/O due to more frequent writes, while a larger buffer can improve performance by reducing the number of write operations. Additionally, setting an excessively large buffer size could result in higher memory consumption, especially when multiple concurrent uploads occur. Thus, it is crucial to choose an optimal size to balance memory usage and upload performance.
An effective use of the upload_buffer_size directive is in conjunction with other settings, such as upload_store, which determines where to store uploaded files, and upload_pass, which specifies how to handle the request after the file is uploaded. Combining these directives allows for efficient upload handling and management.
Config Example
location /upload {
upload_buffer_size 16k;
upload_pass /upload_handler;
upload_store /var/uploads;
}Setting a very low buffer size may degrade the performance of file uploads, leading to delayed responses.
Using a buffer size larger than required can cause excess memory usage, especially under high concurrent uploads.