By default upload objects in chunks of 100

[planemad]

Many of the mapping disasters I have come across in OSM are due to large JOSM changesets going bad. Examples:

• ​https://www.openstreetmap.org/user/PlaneMad/diary/35762
• ​http://tasks.openstreetmap.in/project/28

Both changesets were created with JOSM and was massive (>1000 objects). A network error or interruption during such an upload is a recipe for disaster. One will end up with unsynchronized data, conflicts, duplicates and a frustrated mapper can easily lose patience trying to force his changes as there is little help available on what to do in such a scenario.

I always upload in chunks of 100 objects as a default, so that recovery from a failed upload is less painful. This should be a default setting in JOSM and only advanced users should change it if they feel necessary.

Note: This is a bigger concern in developing countries where internet connectivity is not reliable and interruptions are common.

[bastiK]

Closed as duplicate of #5215.
Uploading in chunks of 100 objects is not a good default behavior, as long as the upload order is "all nodes first, then ways, then relations". What you will end up with is cancelled uploads with 1000s of untagged nodes and no ways.

In general, the current "all or nothing" approach is correct, we "just" need to avoid duplicate upload of an entire changeset that only adds objects, but doesn't modify or delete any.

[planemad]

Thanks for clarifying, I had assumed the order is defined by chronological order of changes..