e-Biz Impact version 5.4.5 introduces “shared memory,” which is transparent for end-users. Shared memory affects how distributed function calls (DFCs) are sent from one application to another, and from one controller to another.
Prior to e-Biz Impact version 5.4.5, interprocess communication used TCP sockets, which required one TCP port per controller.
e-Biz Impact shared memory:
Retrieves memory regions from the operating system
Grants access by consumer or server threads to one or more memory regions (for example, one application calls other application using a standard DFC)
Protects memory regions for concurrent access using an elaborate system of semaphores and thread queues
Distributes access to shared memory regions by prioritizing the regions used most frequently
Shared memory architecture is similar to print spoolers. Access to a resource is made on a first come, first serve basis. Each request is queued until a resource is made available for it, then the request receives dedicated access to the shared memory region. Benefits of shared memory include:
Internal TCP port requirements are removed. Only one port is required for external communication.
Solutions are more scalable. Controller memory footprint is smaller and its size is controlled. Controller memory no longer increases as more controllers and applications are added to the same cluster.
Data transfer between controllers is faster because it no longer requires TCP handshaking.
Controllers can exchange larger DFCs with other controllers because the DFC is no longer limited by the socket capacity.
Better thread management by the controller for communication with client applications in other controllers. Prior to e-Biz Impact version 5.4.5, a controller could allocate up to one thread for each function call external to the controller. This led to excessive thread use and could cause controllers to fail when exceeding tunable thread limits.
Because shared memory requires no user configuration
or interaction, this functionality is not discussed in any other
e-Biz Impact documentation.
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