[osmosis-dev] deadlock when extracting bounds with 0.41 but not 0.40.1

[WanMil]

> Hi Eric,
>
>
> On 13 December 2012 23:18, Eric Fernandez <zeb at zebulon.org.uk
> <mailto:zeb at zebulon.org.uk>> wrote:
>
>     Hi,
>
>     This is a follow-up to the thread here:
>     http://lists.openstreetmap.org/pipermail/osmosis-dev/2012-September/001333.html
>
>     I am experiencing the same hanging issue with osmosis 0.41 with the GB
>     map from , which I did not have with osmosis 0.40.1.
>
>     The command I use is the same one (as described in
>     http://wiki.openstreetmap.org/wiki/Mkgmap/help/options#Using_precompiled_bounds_for_the_address_index):
>
>     ./osmosis-0.41/bin/osmosis --read-pbf file=great_britain.osm.pbf
>     outPipe.0=1 --tee 2 inPipe.0=1 outPipe.0=2 outPipe.1=3 --buffer
>     inPipe.0=3 outPipe.0=4 --buffer inPipe.0=2 outPipe.0=5 --tag-filter
>     accept-relations boundary=administrative,postal_code inPipe.0=4
>     outPipe.0=6 --used-way inPipe.0=6 outPipe.0=7 --tag-filter
>     reject-relations inPipe.0=5 outPipe.0=8 --tag-filter accept-ways
>     boundary=administrative,postal_code inPipe.0=8 outPipe.0=9 --used-node
>     inPipe.0=9 outPipe.0=10 --used-node inPipe.0=7 outPipe.0=11 --merge
>     inPipe.0=10 inPipe.1=11 outPipe.0=12 --write-pbf
>     file=great_britain-boundaries.osm.pbf omitmetadata=true
>     compress=deflate inPipe.0=12
>
>     In his answer, Andrew Byrd explains there may be a deadlock problem
>     with the inputs for the merge, but this command was working with
>     osmosis-0.40.1, and normally is dealing with this issue already. Is
>     there any reason that the new 0.41 version leads to the issue?
>
>
> Andrew is correct, the deadlock is expected behaviour with your pipeline
> structure.  Splitting data with a --tee and then recombining with a
> --merge should not be done in the same pipeline.
>
> As to why it works in 0.40.1 and not 0.41 I'm not sure, but there were
> major changes made to the DataPostbox class which is used as a data
> buffer between threads.  It is possible that these changes have
> triggered your deadlock condition, although I'm not aware of anything
> specific.  It *may* be possible to avoid the deadlock by specifying a
> large bufferCapacity on your --buffer tasks, but this isn't recommended
> as you'll probably still run into deadlock conditions at some point in
> the future.
>
> Brett
>

By the way: the command described on
http://wiki.openstreetmap.org/wiki/Mkgmap/help/options#Using_preprocessed_bounds_for_the_address_index
was changed in September to the correct non deadlock prone after I have 
observed the same problem. Please check the page again for the correct 
command line.

WanMil