Checked the supposedly broken routes, indeed they all have exactly the same length. So yes this is down to non-deterministic node ordering caused by parallel sorting/parsing. We can't fix this, it is just a side-effect of parallel parsing done by osmium and parallel sorting. It might be desirable to have consistent soriting, but not at the cost of removing parallelization. So this isn't a bug after all.
The "random" JSON ordering is due to using `std::unordered_map` (you might guess the effect of that from its name). On Wed, Jul 1, 2015 at 3:19 PM, Florian Lohoff <[email protected]> wrote: > On Wed, Jul 01, 2015 at 02:37:25PM +0200, Patrick Niklaus wrote: >> Confirmed on current develop branch using the Isle of Man extract. >> Currently bisecting to find out which change caused this. It is >> expected that pre-processing is not 100% deterministic, since we use >> parallel sorting (node IDs will change), so the JSON response will >> always have a different checksum. However the geometry should always >> be the same. >> >> In theory it could happen that two paths with exactly the same travel >> time get chosen in different files (because of different node ids, so >> the edges are traversed in different order). > > Even with the same travel time it'll be very much appreciated if there > was a deterministic ordering (which is the route and which the > alternate) - In the end by highest osm node id or street name or > whatever. > > And it seems the order of the json result is also "random". I know > that its not specified what order an json dictionary/object gets > serialized but its interesting to see. > > BTW: I have seen this kind of route flap before 0.3.9 IMHO probably even > before 0.3.4 - It just got more anoying as i process a lot more routes > so the noise went way up. > > Flo > -- > Florian Lohoff [email protected] > We need to self-defense - GnuPG/PGP enable your email today! > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.10 (GNU/Linux) > > iQIVAwUBVZPo2ZDdQSDLCfIvAQpY8w//SKS6FnIKV3agk1TIYKOxMWUqSCFWBv+l > G8QuZSfQB4PAE4JfuV2PtIF8IOceV7MRSQKo6IoA0XOuAzew7wYAgo1vJDh2rwNQ > mwLmxUD2JAaYtt1ci9pqghOwym9nPHYNRNYxSJ+EHL4Ijf2TC2JtH33pHQI0nwvH > djppJPypJ/LxEWCs/AI8TnQ/uetZcXyCB7Y3xSj91PDGcfXkuFpnPQY1fHmBcONW > MiG9W15X/f4tx+E25xRkSeP8VR1Oge2FrzB9UtvtInr9K251YuCwWnEUWb+xEhpG > soK07xcMcXLeAB3CYLf/OxnEuQg4mz6HjV/RH1xCus48d3rJSfJ6AajhB4UPRYEB > 0ZpQUURJPlptX5syBhepaXNNPoRW/dH151Ro0L6lpWPtMvfp2rL6xGy3iFH/BlNC > rZ2oFjMmkrvtTzTtiqvh75YVPG9+XmnGIpFn8adQVcsXW0FloEj7O2lh+LK0qMl7 > rom1/UYTBpHmuWAC/+dwJDjyiZSqWDgrO9yP6x6O1f4jTV1+1/XfeiA8Nu/9JAwX > Z188GY09iPMBOGKSDPHfUfrLf34YRTgyrfZaatpY9GcDeO7QFqRLtiUTzs73HpIP > pNKicGgWmtvzrafQX1yCW0Y66+jKoNqsL/6/KAfeUW6OIBfxwEuuf+daHw4s/cc/ > kOvTF934pIg= > =wRJ5 > -----END PGP SIGNATURE----- > > _______________________________________________ > OSRM-talk mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/osrm-talk > _______________________________________________ OSRM-talk mailing list [email protected] https://lists.openstreetmap.org/listinfo/osrm-talk
