YADE Parameter Reference - Transactional

Diagram

Elements

Transactional - boolean
References Schema: Transactional, Transactional Mapping: transactional TransactionMode Notes This parameter specifies whether a transfer should be processed within a single transaction, i.e. either all objects are successfully transferred or none. Should an error occur during a transfer operation then all transfers will be rolled back. When specifying the value true then the following applies: The AtomicSuffix parameter and AtomicPrefix parameter are used that cause target files to be created with a suffix such as "~" (default) and that causes the respective files to be renamed to their target file name after the transfer of all files has been successfully completed. If at least one file out of a set of files cannot be transferred successfully then no files will be renamed, instead the temporarily created files are removed from the target system. The parameter remove_files that causes files to be removed after successful transfer will be effective only after all files have been successfully transferred. Otherwise no files will be removed.
Element	Type	Required	Description
	boolean Whitespace: collapse		The starting element is a simpleType.

Explanations

This parameter specifies whether a transfer should be processed within a single transaction,

i.e. either all objects are successfully transferred or none.

Should an error occur during a transfer operation then all transfers will be rolled back.

The following applies when the value true is specified:

The AtomicSuffix and/or AtomicPrefix parameters have to be specified to cause target files to be created on the target system with a suffix and/or prefix such as "~".
After the transfer has been completed, the names of these files will then be changed back to their original values.
(See Atomicity)
If at least one file out of a set of files cannot be transferred successfully then no files will be renamed.
Instead the files that were written on the target system under their temporary names will be removed.
The Move operation that causes files to be removed after successful transfer will only be effective after all files have been successfully transferred.
Otherwise no files will be removed.

Transactional transfer requires rename permission on the target host (to remove the atomic prefix / suffix).
Transactional transfer is is a two phase operation and is not 100% reliable - there are situations where rollback is not possible.
- For example, consider the situation where a number of files are transferred transactionally to a remote system, and update - i.e. overwrite - already existing files.
  - If, during the rename/overwrite transfer phase, one of the files to be overwritten has been opened by another process, access to this file will be denied and the transfer will fail.
  - The file copy or move transfer phase can be rolled back but the files that have been overwritten cannot be reverted to their previous state.
All protocols that can be used for transfer to a target support a Rename operation.