A webcron solution will also run equally well on hosts that do offer users such capabilities but is designed as a substitution or replacement.
A script that runs a long time must take into account that it may be terminated at any point by a web server process.
Users may implement a state machine, which allows the script to operate across multiple invocations and run within the limitations imposed by a web host.
providers have restrictions built into their system to avoid overloading their servers and to encourage users to sign up for premium accounts.
Some webcron service providers accept CRON expression in web interface to schedule the job executing time.
For instance, this can be accomplished by using an 'img' HTML element in the header or footer of the website, an Ajax call in a script or an iFrame.
[citation needed] A remote access capable webcron solution is typically[peacock prose] bundled with a pair of client and server components.
[1][non-primary source needed] Remote access usually[peacock prose] offers capabilities that are impossible with other scheduling providers.
[9][non-primary source needed] A typical[peacock prose] implementation of a remote access plugin or module is to incrementally back up files and databases from the web server to the client.
In the case of a remote access capable webcron solution, cron can run the client component to execute the script.
When using a remote access scheduling provider, users usually[peacock prose] have refined control over how communication takes place with the web server.