OpenStreetMap
I just worked for about 3 hours, adding houses, footways am parks... i was nearly finished, and then... - BOOM! JOSM Crashed, now all data is lost... that sucks!
Does JOSM some sort of caching so it may be possible to recover something? if someone has an idea, please let me know...
Discussion
Comment from dcp on 22 October 2009 at 14:09
I have used JOSM now for about 16 months. It has never crashed on me yet!!!
What I do is I upload my data after finishing a logical section. I just won't
take the risk any more that something untoward may happen.
I an just a pessimist I suppose and plan for the worst case and it cannot get
worse than losing 3 hours of work. My sympathies lie with you demi
dcp
Comment from Ævar Arnfjörð Bjarmason on 22 October 2009 at 15:11
I'm afraid not. JOSM keeps its data in memory. Sometimes it's possible on systems like Linux which support this to take a dump of memory right after this happens, I've managed to save e.g. browser forms this way. But for complex Java datastructures that JOSM uses it's going to take a lot more work than 3 hours of work to piece that together from a raw memory dump.
Did you note why JOSM crashed? Did it display a backtrace? If so (and in the future) you should file things like these in its bugtracker so that they won't happen in the future.
JOSM also has really good support for multiple changesets now and other things that make it easy to keep uploading data to the server without compromising the quality of your changesets or edit summaries. I rarely edit with JOSM for more than 10 minutes without uploading to the server now.
Comment from Pink Duck on 23 October 2009 at 08:48
I have had several JOSM crashes over the year, mainly due to running out of Java virtual memory because of memory leaks in its code. It's very frustrating to lose edited data, though usually ends up much quicker the second time around to enter. I tend to save progress as an OSM file as I go, after completing significant areas. To reduce the risk further I close and reopen JOSM occasionally. You can also launch JOSM with command line parameter to increase the available memory to it, but that's can just prolong the inevitable.
Comment from smsm1 on 31 October 2009 at 01:02
I'd recommend regularly saving and uploading so that you don't lose your changes. With recent versions of JOSM you can upload using the same changeset multiple times, rather than having to have a single changeset for each upload. The save regularly mantra comes from office documents, and applies here too.