db/stats_gw: Remove accumulated gateway stats after 30 days

Accumulated gateway stats are much less accurate and helpful than
those for hoods or the global ones. Since they however account for
most of the global stats data, reduce their history in patch.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

ffmap/config.py

@@ -22,6 +22,7 @@ CONFIG = {
 	"event_num_entries": 300,			# Number of events stored per router
 	"global_stat_days": 365,			# Global/hood stats are collected for X days
 	"global_stat_show_days": 60,			# Global/hood stats are shown for X days
+	"global_gwstat_days": 30,			# Accumulated gateway stats are collected for X days
 	"csv_dir": "/var/lib/ffmap/csv",	# Directory where the .csv files for TileStache/mapnik are stored
 	"debug_dir": "/data/fff/fffmonlog",	# Output directory for debug .txt files
 }

ffmap/stattools.py

@@ -483,7 +483,7 @@ def record_hood_stats(mysql):
 	mysql.commit()
 
 def record_gw_stats(mysql):
-	threshold=(utcnow() - datetime.timedelta(days=CONFIG["global_stat_days"])).timestamp()
+	threshold=(utcnow() - datetime.timedelta(days=CONFIG["global_gwstat_days"])).timestamp()
 	time = mysql.utctimestamp()
 	status = router_status_gw(mysql)
 	clients = total_clients_gw(mysql)