[osmosis-dev] osmosis pipelining troubles

[Andrew Byrd]

Hello Marcus,

Using tee followed by merge can trigger deadlock, and I would guess this 
is what's happening in your case:

http://lists.openstreetmap.org/pipermail/dev/2009-June/015945.html

I usually get around the problem by using separate read-xml tasks for 
each sub-pipeline that will be merged at the end of the pipeline. See 
the last example in this section of the Osmosis wiki:
http://wiki.openstreetmap.org/wiki/Osmosis/Detailed_Usage_0.38#--tag-filter_.28--tf.29

-Andrew

On 12/07/2011 10:00 AM, MERIGHI Marcus wrote:
> Hello,
>
> while trying to integrate various processing steps into a rather complex
> pipeline I have run into troubles. Each step alone seems to work, even
> more complex arrangements, but not all of them. (Go to bottom of message
> (3) to see an working example with multiple invocations of osmosis.)
>
> The osmosis commands below (1) stop at "FINE: Waiting for task
> 1-read-xml to complete.", probably forever. CPU utilization goes up
> first and then slowly down to zero, fstat does not show any read
> activity on the input file (anymore).
> I have tried to pin down at what point the processing hangs; everything
> before "--derive-change" works, tested with "--write-null[-change]".
>
> The questions are:
> 1) Am I getting something fundamentally wrong about the way osmosis
>     pipes work?
> 2) Is there any obvious mistake in my parameters?
> 3) Have I hit a bug?
>
> (BTW, basicly I am after simplifying ways; but --simplify-ways leaves
> (now) unused nodes behind; getting rid of them by means of --used-node
> removes poi-type nodes as well (not used in ways and relations).
> Therefore I have to go the long way of diffing before- and after
> --used-node, parse that for "used" (i.e., poi-type) nodes and merge.)
>
> Thanks in advance for any pointers!
>
> Marcus