Sequence Diagram for Cloud Computing

"A sequence diagram is an interaction diagram that shows how processes operate with one another and in what order. It is a construct of a Message Sequence Chart. A sequence diagram shows object interactions arranged in time sequence. It depicts the objects and classes involved in the scenario and the sequence of messages exchanged between the objects needed to carry out the functionality of the scenario. Sequence diagrams are typically associated with use case realizations in the Logical View of the system under development. Sequence diagrams are sometimes called event diagrams, event scenarios." [Sequence diagram. Wikipedia]
This UML sequence diagram example 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 automated teller machine (ATM) UML sequence diagram was created on the base of figure 5 "Sequence diagram" on the webpage "Message Sequence Charts and their Ilk" from the website of the University of California Irvine (UCI) Donald Bren School of Information and Computer Sciences.
"A UML sequence diagram or SD is similar to an MSC but written with a different notation. Presumably the same semantic issues arise, but possibly not since UML semantics are not well-defined. An example is shown in Figure 5.
The timelines are dotted rather than solid, and the name of the component is inside a box at the head of each timeline. The narrow rectangles apparently show when a component is active (unsure precisely what "active" means). An X on a timeline indicates that the component ceases to exist in some sense (unsure precisely how this is meant also). In the example, the Bank timeline has an X simply as an example (presumably the Bank does continue to exist)."
[www.ics.uci.edu/ ~alspaugh/ cls/ shr/ msc.html]
This example of bank ATM sequence diagram 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.

"An example scenario is presented to demonstrate how a common issue tracking system would work:
(1) A customer service technician receives a telephone call, email, or other communication from a customer about a problem. Some applications provide built-in messaging system and automatic error reporting from exception handling blocks.
(2) The technician verifies that the problem is real, and not just perceived. The technician will also ensure that enough information about the problem is obtained from the customer. This information generally includes the environment of the customer, when and how the issue occurs, and all other relevant circumstances.
(3) The technician creates the issue in the system, entering all relevant data, as provided by the customer.
(4) As work is done on that issue, the system is updated with new data by the technician. Any attempt at fixing the problem should be noted in the issue system. Ticket status most likely will be changed from open to pending.
(5) After the issue has been fully addressed, it is marked as resolved in the issue tracking system.
If the problem is not fully resolved, the ticket will be reopened once the technician receives new information from the customer. A Run Book Automation process that implements best practices for these workflows and increases IT personnel effectiveness is becoming very common." [Issue tracking system. Wikipedia]
The UML sequence diagram example "Ticket processing system" 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.

The vector stencils library "UML sequence diagrams" contains 50 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"Sequence diagram ... building blocks.
If the lifeline is that of an object, it demonstrates a role. Note that leaving the instance name blank can represent anonymous and unnamed instances.
Messages, written with horizontal arrows with the message name written above them, display interaction. Solid arrow heads represent synchronous calls, open arrow heads represent asynchronous messages, and dashed lines represent reply messages. If a caller sends a synchronous message, it must wait until the message is done, such as invoking a subroutine. If a caller sends an asynchronous message, it can continue processing and doesn’t have to wait for a response. Asynchronous calls are present in multithreaded applications and in message-oriented middleware. Activation boxes, or method-call boxes, are opaque rectangles drawn on top of lifelines to represent that processes are being performed in response to the message (ExecutionSpecifications in UML).
Objects calling methods on themselves use messages and add new activation boxes on top of any others to indicate a further level of processing.
When an object is destroyed (removed from memory), an X is drawn on top of the lifeline, and the dashed line ceases to be drawn below it (this is not the case in the first example though). It should be the result of a message, either from the object itself, or another.
A message sent from outside the diagram can be represented by a message originating from a filled-in circle (found message in UML) or from a border of the sequence diagram (gate in UML)." [Sequence diagram. Wikipedia]
The example "Design elements - UML sequence diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

"A help desk is a resource intended to provide the customer or end user with information and support related to a company's or institution's products and services. The purpose of a help desk is usually to troubleshoot problems or provide guidance about products such as computers, electronic equipment, food, apparel, or software. Corporations usually provide help desk support to their customers through various channels such as toll-free numbers, websites, instant messaging, or email. There are also in-house help desks designed to provide assistance to employees." [Help desk. Wikipedia]
The UML sequence diagram example "Help desk" 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.

"A schedule or timetable is a basic time management tool consisting of a list of times at which possible tasks, events, or actions are intended to take place, or a sequence of events in the chronological order in which such things are intended to take place. The process of creating a schedule - deciding how to order these tasks and how to commit resources between the variety of possible tasks - is called scheduling, and a person responsible for making a particular schedule may be called a scheduler. Making and following schedules is a fundamental human activity, and learning to do these things effectively is one of the most basic life skills. There are a wide variety of situations in which schedules are necessary, or at least useful.
Schedules are useful for both short periods, such as a daily or weekly schedule, and for long term planning with respect to periods of several months or years. They are often made using a calendar, where the person making the schedule can note the dates and times at which various events are planned to occur. Schedules that do not set forth specific times for events to occur may instead list an expected order in which events either can or must take place." [Schedule. Wikipedia]
The UML sequence diagram example "Checking process" 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.

The vector stencils library "Sequence diagram" contains 32 SysML symbols.
Use it to design your sequence diagrams using ConceptDraw PRO diagramming and vector drawing software.
"A sequence diagram shows, as parallel vertical lines (lifelines), different processes or objects that live simultaneously, and, as horizontal arrows, the messages exchanged between them, in the order in which they occur. This allows the specification of simple runtime scenarios in a graphical manner. ...
If the lifeline is that of an object, it demonstrates a role. Leaving the instance name blank can represent anonymous and unnamed instances.
Messages, written with horizontal arrows with the message name written above them, display interaction. Solid arrow heads represent synchronous calls, open arrow heads represent asynchronous messages, and dashed lines represent reply messages. If a caller sends a synchronous message, it must wait until the message is done, such as invoking a subroutine. If a caller sends an asynchronous message, it can continue processing and doesn’t have to wait for a response. Asynchronous calls are present in multithreaded applications and in message-oriented middleware. Activation boxes, or method-call boxes, are opaque rectangles drawn on top of lifelines to represent that processes are being performed in response to the message (ExecutionSpecifications in UML).
Objects calling methods on themselves use messages and add new activation boxes on top of any others to indicate a further level of processing.
When an object is destroyed (removed from memory), an X is drawn on top of the lifeline, and the dashed line ceases to be drawn below it (this is not the case in the first example though). It should be the result of a message, either from the object itself, or another.
A message sent from outside the diagram can be represented by a message originating from a filled-in circle (found message in UML) or from a border of the sequence diagram (gate in UML)." [Sequence diagram. Wikipedia]
The SysML shapes example "Design elements - Sequence diagram" is included in the SysML solution from the Software Development area of ConceptDraw Solution Park.

This UML sequence diagram of order processing center (OPC) was created on the base of sequence diagram from the software architecture documentation wiki of the Software Engineering Institute (SEI) of Carnegie Mellon University (CMU).
[wiki.sei.cmu.edu/ sad/ index.php/ Image:OPCRuntimeRefinementView_ PP2.png]
"Order processing is the process or work-flow associated with the picking, packing and delivery of the packed items to a shipping carrier. Order processing is a key element of order fulfillment. Order processing operations or facilities are commonly called "distribution centers"." [Order processing. Wikipedia]
This order processing center UML sequence 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.

"Request methods.
An HTTP 1.1 request made using telnet. The request, response headers and response body are highlighted.
HTTP defines methods (sometimes referred to as verbs) to indicate the desired action to be performed on the identified resource. What this resource represents, whether pre-existing data or data that is generated dynamically, depends on the implementation of the server. Often, the resource corresponds to a file or the output of an executable residing on the server. The HTTP/ 1.0 specification:section 8 defined the GET, POST and HEAD methods and the HTTP/ 1.1 specification:section 9 added 5 new methods: OPTIONS, PUT, DELETE, TRACE and CONNECT. By being specified in these documents their semantics are well known and can be depended upon. Any client can use any method and the server can be configured to support any combination of methods. If a method is unknown to an intermediate it will be treated as an unsafe and non-idempotent method. There is no limit to the number of methods that can be defined and this allows for future methods to be specified without breaking existing infrastructure. For example, WebDAV defined 7 new methods and RFC5789 specified the PATCH method.
GET.
Requests a representation of the specified resource. Requests using GET should only retrieve data and should have no other effect. (This is also true of some other HTTP methods.)" [Hypertext Transfer Protocol. Wikipedia]
The UML sequence diagram example "GET request" 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.