CCISMEM (ccism) uses a Named Shared Memory communications method to transfer date between two processes on the same Windows system. Both the client and the server application must reside on the same Windows system.

These shared memory transfers are typically about as fast as its possible to transfer data buffers between processes. Individual data transfers that fit within the shared memory segment are typically several context switches faster than using TCP/IP in loopback mode to move the same data. As buffer sizes grow the difference becomes less noticeable, but is still present. By default, shared memory segments are 8K in size, but this is easily configurable using the cci.ini configuration file options.

When using Fileshare with the CCISM protocol, ensure the server is started using the /sc switch. This switch starts Fileshare in synchronous communications mode, which gives the best performance.

To also use clients located on other systems, you must configure Fileshare Server to use CCITCP as well as CCISM. To do this, in cci.ini, set the following configuration options:

-cm ccitcp -cm ccism

Using two protocols within a single Fileshare Server prevents Fileshare Server being used in synchronous mode; this is the only functionality that is lost with this type of configuration.

From a client perspective, the default CCITCP functionality doesn't require much FHREDIR.CFG configuration. When using CCISMEM you will need to use the following client options:

/cm ccism
Note: When using CCISMEM, the /MA parameter should not normally be used as it has a different meaning in the context of Named Shared Memory. The /MA option is equivalent to using the mem_files_location option in the cci.ini configuration file.