[Tile-serving] [osm2pgsql] use one instance of node-persistant-cache per thread (#257)

[Paul Norman]

I noticed that it moved node cache reporting information to the end of the import

```
Maximum node in persistent node cache: 2445279231
Maximum node in persistent node cache: 2445279231
...repeated...
node cache: stored: 2013054242(100.00%), storage efficiency: 86.67% (dense blocks: 2125712, sparse nodes: 72947236), hit rate: 99.76%
```


Other than that, I'm processing hourly diffs without errors
```
time (for n in `seq 555 654`; do 
echo $n
~/osmosis/bin/osmosis --rxc "$HOME/diffs/008/$n.osc.gz" --simc --wxc - | ~/src/osm2pgsql/osm2pgsql -d gis -a -S ~/src/osm2pgsql/default.style --flat-nodes ~/nodes.bin -C 2000 --slim --number-processes 8 -
sleep 10
done) 2>&1 | tee log.txt
```

---
Reply to this email directly or view it on GitHub:
https://github.com/openstreetmap/osm2pgsql/pull/257#issuecomment-71573711
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tile-serving/attachments/20150126/5b3d61cf/attachment.html>