Auxiliary functions

An auxiliary function is an internal function that assists the MSIF transfer services during a SendFile, ProvideFile, ReceiveFile, or DownloadFile scenario. For each auxiliary function that an MSIF transfer service employs, it creates a separate auxiliary-function scenario (see States of an auxiliary function). An auxiliary-function scenario and its corresponding file-transfer scenario both have the same MSIF reference, and so can be correlated.

Normally, each auxiliary-function scenario runs fully autonomously and does not require any kind of administration, monitoring, or other attention. Even if an auxiliary function encounters an error, this usually presents as an error in the corresponding file-transfer scenario and is addressed by administering that scenario, for example by issuing a recover or cancel command. However, in rare, exotic situations direct administration of an auxiliary-function scenario is required. How to identify and address such situations is described in MSIF administrator tasks.

Depending on the properties of a file transfer scenario, the MSIF transfer service creates internal copies of a file in its work directory. Temporary copies of a file are created, for example, if the file is processed in store-and-forward mode, or if the file data must be compressed, decompressed, or converted. After a file transfer scenario has finished, the MSIF transfer service automatically deletes all temporary copies of a file. To create and delete such copies, it uses the following auxiliary functions:

FS

For file-transfer scenarios where a temporary copy of a file is created, this auxiliary function creates in the file system of the host one or more copies of the file that is to be transferred. The name of each copy begins with the MSIF reference of the corresponding file transfer scenario. After the file transfer scenario has finished, the MSIF transfer service uses this auxiliary function to delete these copies. The directory in which the copies are located is specified by the EfaDataDirectory attribute of the CO DnfEfaParameters of type DnfEfaParameters.

SAGSD

For a SendFile or ProvideFile scenario, the MSIF transfer services use this auxiliary function to create, for use by the SAG, copies of the file that is to be transferred. (When CommType is set to MQHA, this auxiliary function uses LFT to transfer the file contents from the host to the SAG.) The name of each copy is identical to the MSIF reference of the corresponding file-transfer scenario. After the file-transfer scenario is complete, the MSIF transfer service uses this auxiliary function to delete these copies. The directory in which each of these copies is located is determined by the following SAG communications options:

For the copy on the SAG: SagSubDirectory
For the copy on the host: TransferDirectory

SAGRC

For a ReceiveFile or DownloadFile scenario, the MSIF transfer service uses this auxiliary function to create, for use by the SAG, copies of the file that is to be transferred. (When CommType is set to MQHA, this auxiliary function uses LFT to transfer the file contents from the SAG to the host.) The name of each copy is identical to the MSIF reference of the corresponding file-transfer scenario. After the file-transfer scenario is complete, the MSIF transfer service uses this auxiliary function to delete these copies. The directory in which each of these copies is located is determined by the following SAG communications options:

For the copy on the SAG: SagSubDirectory
For the copy on the host: TransferDirectory

A file-transfer scenario cannot be cleaned up unless all of its associated auxiliary-function scenarios have the condition finished. For example, an auxiliary-function might be unable to delete a copy of a file after the corresponding file-transfer scenario finishes. When this happens, an MSIF administrator must clean up the corresponding auxiliary-function scenario manually, as described in MSIF administrator tasks.