Version 15 (modified by Fran Boon, 14 years ago) ( diff )

No longer using LP for this

Blueprint for Synchronisation

We need to be able to support synchronising data between instances:

The UUIDs have already been configured: DeveloperGuidelinesDatabaseSynchronization

We need to extend this by Exporting the tables (CSV is best-supported within Web2Py currently)
"complete database backup/restore with db.export_to_csv_file(..),db.import_from_csv_file(...),
reimporting optionally fixes references without need for uuid"

Initially this can be done using appadmin, but we want to make a user-friendly way of dumping all relevant tables.
Need clear list of which tables to include:

  • not lookup lists which are the same across sites
    • e.g. OpenStreetMap/Google Layers (but WMS/SOS Layers Yes. Shapefiles Layers Yes if uploads copied across as well)
  • not site-specific stuff such as system_config, gis_keys, etc

Export tables as CSV (in Controller):

def export():
    return s.getvalue() 

Import tables at the other end:

def import_and_sync():
    if form.accepts(request.vars):
        # for every table
        for table in db.tables:
        # for every uuid, delete all but the most recent
            for item in items:
    return dict(form=form) 

Create an index manually to make the search by uuid faster.

other related threads:

There is a simple 1-table example appliance which has the ability to do syncs via XML-RPC:

In Sahana2 the record ids are UUIDs built from each instance's 'base_uuid'

There is a sync_instance table:

CREATE TABLE sync_instance (
    base_uuid VARCHAR(4) NOT NULL, -- Instance id
    owner VARCHAR(100), -- Instance owner's name
    contact TEXT, -- Contact details of the instance owner
    url VARCHAR(100) DEFAULT NULL, -- Server url if exists
    last_update TIMESTAMP NOT NULL, -- Last Time sync with the instance
    sync_count INT DEFAULT 0, -- Number of times synchronized
    PRIMARY KEY(base_uuid)
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