Shared Database

Create Read Update Delete

• Sharing a common database does not require to modify components, if they all can support the same schema
• Components can communicate by creating, updating and reading entries in the database, which can safely handle the concurrency

Disruptor

Next Publish WaitFor Get

• Lock Free: Single Writer, Multiple Consumers
• Cache-friendly Memory Ring-buffer
• High Throughput (Batched Reads) and Low Latency

Message Bus

Publish Subscribe Notify

• A message bus connects a variable number of components, which are decoupled from one another.
• Components act as message sources by publishing messages into the bus; Components act as message sinks by subscribing to message types (or properties based on the actual content)

• The bus can route, queue, buffer, transform and deliver messages to one or more recipients
• The “enterprise” service bus is used to implement the SOA style

File Transfer

Write Copy Watch Read

• A component writes a file, which is then copied on a different host, and fed as input into a different component.

• The transfers can be batched with a certain frequency
• Transferring files does not require to modify components

Linkage

Load Unload Call Read/Write

• Statically Linking components enables them to call each other, but also to share data in the same address space

• Dynamic linking also enables the components to be loaded and unloaded without stopping the whole system

Tuple Space

In Out Rd

• A tuple space acts like a shared database, but offers a much simpler set of primitives and persistence guarantees
• Components can write tuples into the space (Out) or read tuples from it (Rd).
• Components that read tuples can also atomically take them out of the space (In)

• Extensions for the connector are available that support different kinds of synchronization (blocking or non-blocking reads), in addition to the basic data flow primitives
• A tuple space fits with the constraints of the Blackboard style and the Master/Worker pattern

Web

Get Put Delete Post

• Components reliably transfer state among themselves using the GET, PUT, DELETE primitives. POST is used for unsafe interactions.
• Components refer to each other with global addresses (URI)
• The Web is the connector used in the REST (Representational State Transfer) architectural style