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Operations are seen as a sequences of messages which collectively correspond to a full operation. For example the Get operation consists of a sequence of 5 messages as illustrated below. Note that it is divided, since the GetTime part can cover request to several pillars while the Get part only concern one pillar. Note that the actual data transmission is not included here although it will be part of a full operation.
The Get operation can begin by asking pillars who will be the fastest, or it can start by actually sending a get message for a specific default pillar.
In the strict interpretation of single operations this will be seen as two operations
- GetTime
- Get
The difference between the two get scenarios will be that the first will both consist of a GetTime and a Get operation, while the later will only consist of a Get.
Reuse and overlap between operations
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Reuse and overlap between operations
The operations are design to have as many similarities and overlapping definitions as possible. For instance the getChecksums must work simmilar to Get. Paging of data and parameters must work in the same way.
Paging af requests
It must be possible to make paging of request parameters. Paging of parameters can for instance be the case for object ids in a random check of files. It is needed since we cannot assume that clients can make prior pagination.
Software
Independence
In the design we need to ensure that we are as independent of the software chosen as possible. If special features are used, e.g. for optimisation, then the design must be flexible enough to skip use of the special features at a later stage.
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