Formats: Managed, Built-In, and Dynamic
A format defines the set of fields that a message can contain: including field names and data types.
TIBCO FTL software supports three broad categories of format: managed, built-in, and dynamic formats. These categories have differing constraints and performance characteristics.
Dynamic Format
An application can define a format dynamically, as it constructs a message. That is, the sending program implicitly determines the set of fields and their data types as it sets field values.
When a program creates a message, and specifies an unrecognized format name (that is, neither built-in nor preloaded), then TIBCO FTL software automatically treats it as a dynamic format.
While easy to use, dynamic formats are inefficient because each message must be self-describing. That is, a dynamic format message necessarily includes its own format metadata. Expect larger message sizes, slower transmission, slower processing, and longer field access times.
Dynamic formats are useful for rapid prototyping projects. To improve performance, you can switch to defining the application’s formats as managed formats when the project nears the production stage.
Unnamed Dynamic Format
A program can create a message with a dynamic format, but supply null as the format name. Such unnamed dynamic formats are single-use. Administrators cannot ever upgrade them to managed formats.
You can use unnamed dynamic formats as a convenience when you cannot determine the structure and content of a message in advance. Unnamed formats save you the effort of naming the formats and keeping track of the names.
The performance of unnamed dynamic formats is identical to named dynamic formats.
Managed Format
Application architects and developers determine the set of formats that an application needs. Administrators then define those managed formats globally.
Administrators make managed formats available to an application by including them as preload formats for the application.
Programs can use these managed formats to compose new messages, or to unpack inbound messages. A message with a managed format is small and fast. It does not carry format metadata because that metadata is available to applications from the FTL server.
For efficiency and for safety, administrators can use the Manage All Formats and Dynamic Message Formats parameters to restrict the formats available to some or all of the applications in a realm. That is, administrators can require that applications use only preload formats and built-in formats, and prohibit applications from using dynamic formats.
Built-In Format
TIBCO FTL software defines a set of highly optimized built-in formats, which are defined within the base library and always available to all applications. No administrative action is required to make them available.
The performance characteristics of built-in formats are similar to managed formats. When used properly, a built-in format can outperform a managed format.
For more information, see Built-In Formats Reference.