- Static file materialization is not enabled.
- Uncaught exceptions displayed in the browser
- Exceptions thrown in error handler, not logged
- System logging in
var/report, highly detailed.
You should use the Developer mode while you are developing
customizations or extensions. The main benefit to this mode is that
error messages are visible to you. It should not be used in production
because of its impact on performance. In Developer mode, static view
files are generated every time they are requested. They are written to
pub/static directory, but this cache is not used. This has big
performance impact, but any changes a developer makes to view files
are immediately visible.
Uncaught exceptions are displayed in the browser, rather than being
logged. An exception is thrown whenever an event subscriber cannot be
System logging in
var/report is highly detailed in this mode.
- Deployment phase on the production system; highest performance
- Exceptions are not displayed to the user -- written to logs only.
- This mode disables static file materialization.
- The Magento docroot can have read-only permissions.
You should run Magento in Production mode once it is deployed to a
Production mode provides the highest performance in Magento 2.
The most important aspect of this mode is that errors are logged to
the file system and are never displayed to the user. In this mode,
static view files are not created on the fly when they are requested;
instead, they have to be deployed to the
pub/static directory using
the command-line tool. The generated pages will contain direct links
to the deployed page resources.
Any changes to view files require running the deploy tool again.
Because the view files are deployed using the CLI tool, the web user
does to need to have write access. The Magento
can have read-only permissions, which is a more secure setup on a
publicly accessible server.