Asynchronous Thumbnail Generation¶
To optimize response times, generation of thumbnails can be done asynchronously. Usage of asynchronous thumbnail
generation is determined in the image view helpers usage with the
async flag. When the flag is used, a link to the
thumbnail controller returned instead of rendering the thumbnail if the thumbnail hasn’t already been rendered.
The thumbnail controller takes a thumbnail object, renders it, if not already done, and redirects to the
To use asynchronous thumbnail generation set the
async parameter to
TRUE in the image view helpers,
see Media ViewHelper Reference.
The configuration setting
Neos.Media.asyncThumbnails is used to determine if asynchronous thumbnails are rendered
when creating thumbnails for configured Thumbnails Presets.
The setting is additionally used as the default value for the
see Media Command Reference.
Since several simultaneous requests for thumbnails can occur, depending on browser and concurrent users, busy servers
can experience performance issues. Therefore it is recommended to configure the server to run the command
media:renderthumbnails often or use a job queue by listening to the
thumbnailCreated signal and calling
refreshThumbnail for the thumbnail in the thumbnail service.
crontab to run the render command every minute:
* * * * * /path/to/site/flow media:renderthumbnails
media:createthumbnails to refresh thumbnails.