UML activity diagram - Servlet container

"Web container (also known as a Servlet container) is the component of a web server that interacts with Java servlets. A web container is responsible for managing the lifecycle of servlets, mapping a URL to a particular servlet and ensuring that the URL requester has the correct access rights. A web container implements the web component contract of the Java EE architecture, specifying a runtime environment for web components that includes security, concurrency, lifecycle management, transaction, deployment, and other services. A web container provides the same services as a JSP container as well as a federated view of the Java EE platform APIs." [Web container. Wikipedia]
The UML activity diagram example "Servlet container" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

This example of bank ATM UML activity diagram was created on the base of UML use case diagram of automated teller machine from the course "Thinking in Java, 2nd edition, Revision 9" by Bruce Eckel published on the website of the Computer Science and Electrical Engineering Department of the University of Maryland, Baltimore (UMBC).
"If you are designing an auto-teller, for example, the use case for a particular aspect of the functionality of the system is able to describe what the auto-teller does in every possible situation. Each of these “situations” is referred to as a scenario, and a use case can be considered a collection of scenarios. You can think of a scenario as a question that starts with: “What does the system do if...?” For example, “What does the auto-teller do if a customer has just deposited a check within the last 24 hours, and there’s not enough in the account without the check having cleared to provide a desired withdrawal?”
Use case diagrams are intentionally simple to prevent you from getting bogged down in system implementation details prematurely...
Each stick person represents an “actor,” which is typically a human or some other kind of free agent. (These can even be other computer systems, as is the case with “ATM.”) The box represents the boundary of your system. The ellipses represent the use cases, which are descriptions of valuable work that can be performed with the system. The lines between the actors and the use cases represent the interactions.
It doesn’t matter how the system is actually implemented, as long as it looks like this to the user."
[csee.umbc.edu/ courses/ 331/ resources/ tij/ text/ TIJ213.gif]
This automated teller machine (ATM) UML use case diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.

This Azure cloud architecture pattern diagram template was created on the base of figure in the article "Valet Key Pattern" from the Microsoft Developer Network (MSDN) website.
"Valet Key Pattern.
Use a token or key that provides clients with restricted direct access to a specific resource or service in order to offload data transfer operations from the application code. This pattern is particularly useful in applications that use cloud-hosted storage systems or queues, and can minimize cost and maximize scalability and performance. ...
Client programs and web browsers often need to read and write files or data streams to and from an application’s storage. ...
Data stores have the capability to handle upload and download of data directly, without requiring the application to perform any processing to move this data, but this typically requires the client to have access to the security credentials for the store.
... applications must be able to securely control access to data in a granular way, but still reduce the load on the server by setting up this connection and then allowing the client to communicate directly with the data store to perform the required read or write operations. ...
To resolve the problem of controlling access to a data store where the store itself cannot manage authentication and authorization of clients, one typical solution is to restrict access to the data store’s public connection and provide the client with a key or token that the data store itself can validate.
This key or token is usually referred to as a valet key. It provides time-limited access to specific resources and allows only predefined operations such as reading and writing to storage or queues, or uploading and downloading in a web browser. Applications can create and issue valet keys to client devices and web browsers quickly and easily, allowing clients to perform the required operations without requiring the application to directly handle the data transfer. This removes the processing overhead, and the consequent impact on performance and scalability, from the application and the server." [msdn.microsoft.com/ ru-RU/ library/ dn568102.aspx]
The Azure cloud system architecture diagram template "Valet key pattern" for the ConceptDraw PRO diagramming and vector drawing software is included in the Azure Architecture solutin from the Computer and Networks area of ConceptDraw Solution Park.