1. A method comprising: receiving, by a web application system designated as database-side application server, a database notification from a database server, the database notification indicating that an update of a user interface item has occurred in a database, the database notification being generated by the database server in response to a request from a user device, the user device including a browser, the request being a request to receive information when any state change occurs at the database server, the request being received through a client-initiated communication channel; from the database-side application server, initiating communication with the user device through a server-initiated communication channel that is different from the client-initiated communication channel, including: sending, by the database-side application server and to an intermediate web application system designated as a web-side application server, a notification for opening a communication channel; and opening the server-initiated communication channel to the user device by the web-side application server, wherein a delay in opening the server-initiated communication channel by the web-side application server does not block operations of the database-side application server that occur after the database-side application server sent the notification to the web-side application server; generating, by the database-side application server, instructions for refreshing the user interface item in the browser according to the update of the user interface item that occurred in the database; and pushing the instructions to the user device for refreshing the user interface item as displayed in the browser according to the update of the user interface item in the database, wherein pushing the instructions to the user device comprises: sending the instructions by the database-side application server to the web-side application server; and sending the instructions by the web-side application server through the server-initiated communication channel to the user device through a web server, wherein a delay in sending the instructions to the user device by the web-side application server does not block operations of the database-side application server that occur after the database-side application server sent the instructions to the web-side application server.