Shared Memory Transport: Parameters Reference

These parameters are specific to shared memory transports in the configuration interface.

For web API access to transport definitions, see Transport Definition Objects.

GUI Parameter JSON Attribute Description
Segment Name segment_name Required.

Name of the shared memory segment.

Use only ASCII alphanumeric characters in the segment name.

The maximum length of the segment name depends on the operating system:

  • Mac OS X: 16 characters
  • UNIX: PATH_MAX
  • Windows: MAX_PATH
Segment Size size

Size of the shared memory segment.

Directory Name dirname Optional.

Each shared memory transport uses a scratch directory to store information about the runtime transports that use its shared memory segments.

When present, this directory path specifies the scratch directory. (If the directory you specify doesn’t exist in the file system, the transport attempts to create it.)

When absent, the default scratch directory is /tmp (or its equivalent on non-UNIX platforms).

Global Scope globalscope Windows only (on other platforms, the base library ignores this parameter).
On Windows platforms, shared memory segments can have either of two scopes:
  • Local to a specific user, that is, a login name.
  • Global, that is, available to all user names.

If the process instances using the transport run with different user names, then you must use a global segment. To specify a global segment, enable this parameter (or in the web API, set the JSON attribute to global).

You may use a local segment only if the process instances using the transport all run with the same user name. To specify a local segment, specific to the user running the application process, disable this parameter (or in the web API, set the JSON attribute to local).

For further information, see documentation for the CreateFileMapping function on the Microsoft Developer Network (ISDN) web site.

See also, Buffer and Performance Settings for Transports.

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