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Projects:Retail Master Data Synchronization



Bulbgraph.png   The improvements implemented as part of this project apply starting from RR15Q3

This project has as goal to improve master data loading by the WebPOS client (or other mobile applications) from the server.

The main topic is to handle larger volumes of master data by implementing paged requests to the server to load master data.

Also as part of this project, the consistency checking of loaded data on the client will be improved to ensure that, if the application has been loaded, it will be completely functional.

Technical Specification

This project has been implemented in several steps, each one implementing a small feature or improvement.

Phase 1: Consistency Checks

The first phase implements ad improves several checks to ensure that, if the application has finished loading and the POS window is shown, the application is completely functional and all required data has been loaded. The following checks have been implemented:

Phase 2: Implement Paged Requests

The second phase takes care of implementing a mechanism to request model data in batches of 35000 records. This has been done to improve both server and client-side performance.

After processing each batch of records of a model, the next batch is requested and processed. This is repeated until the model is fully loaded.

The server-side performance improvement comes from the fact that each query needs to handle a smaller set of data.

On the other hand, the client side performance improvement comes from the reduction of the xhr response objects (as a reference data, a 130000 product response was roughly 80 megabytes). Browsers on low-end devices, such as tablets or computers with a very limited memory, usually crash when handling very big objects. With paged requests the size of the javascript objects is limited and therefore low-end devices are capable of loading big master data models.

Phase 3: Serialized Loading and Visual Login

This phase implements both a performance improvement on the server and a visual improvement on the client.

Phase 4: Further improvements

This last phase implements an additional improvement to the consistency checks. If the application has master data loaded, and the next full master data load fails, it is not always necessary to force a full refresh.

If a model fails to load and the request was not part of a paged request, the old model data is still there, so it should be possible to work, even with old data. The next full or incremental refresh will take care of updating the data.

Therefore, the only case in which the application will force a full refresh is if a paged request has failed, only after it has already loaded part of the model (because the first load would have deleted the old data).

Tested Scenarios

In order to verify this project several scenarios have been tried, combining different situations, such as online and offline connections, failing and correct preference loading and failing and correct master data loading.

No previous loading done

For the following cases a popup is shown explaining the error and prompting to reload or logout to fix the problem. In all cases, if the error is fixed the login process proceeds normally and the application loads correctly:

A full refresh has already been done

Since the terminal object is a critical part of the application, these are the only cases in an incremental load in which a reload will be required to try to request the object again:

The following cases will be transparently ignored to allow the user to continue working:

Full refresh after a full refresh has been done

These two cases act transparently since the old data is still present in the model:

Since the first request will wipe the old data, a full refresh will be required if:

Automated Tests

Since this project modifies the entire loading process, all tests are implicitly checking that this project is correctly working.

A new test will be added with a big master data model (~100000 products) to verify that the paged loading is working.

Additional Documentation

Feature Request:

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