[OSM-dev] Server timeouts

[David Earl]

Sometimes downloading from the API in JOSM I get a message along the 
lines of "malformed XML", which I think is just caused by the XML being 
truncated, which in turn I am speculating is caused by the server 
exceeding a limit for the time allowed.

If I immediately redo the query it almost always succeeds - and the 
download amount starts counting almost immediately. So I'm guessing the 
area query to determine what to download is being cached and as a result 
my download takes much less time and succeeds.

If I'm right, this seems to me to increase load on the server, because 
while my original query is fast the second time, most of the first 
download time is wasted. If you've got as far as completely answering 
the area query, would it make sense to then complete the whole 
transaction? i.e. apply the timeout (possibly a shorter timeout) to the 
query phase only. Or restart the clock at the start of downloading.

As well as reducing overall load, it would reduce downloader frustration.

I say this in complete ignorance of what is actually going on, mere 
speculation. But something odd is clearly happening.

David