Discovered when investigating T232817: Wikimedia maps instability (maps.wikimedia.org):
root@maps1002:/tmp# ls -lat | tail -20 -rw-r--r-- 1 kartotherian kartotherian 845 Jun 19 15:37 geojson-mapnikify-b0b6cc6a25e82f34acfc7c950e43912a.png -rw-r--r-- 1 kartotherian kartotherian 894 Jun 19 15:37 geojson-mapnikify-66476b9bd9966fb8645267d6fc5718d2.png -rw-r--r-- 1 kartotherian kartotherian 878 Jun 19 15:37 geojson-mapnikify-194fe197a56b05757046ab57d6468626.png -rw-r--r-- 1 kartotherian kartotherian 799 Jun 19 15:37 geojson-mapnikify-26cb25d09ed8a6b7730b4e5d62200df9.png -rw-r--r-- 1 kartotherian kartotherian 888 Jun 19 15:37 geojson-mapnikify-99b5b9fea2c17c658869a0dc47bf0e42.png -rw-r--r-- 1 kartotherian kartotherian 869 Jun 19 15:37 geojson-mapnikify-d851fcc5c84aab6aa53969d91ba1b58f.png -rw-r--r-- 1 kartotherian kartotherian 763 Jun 19 15:37 geojson-mapnikify-392b9cab2b3ed7f65192fab563e2780a.png -rw-r--r-- 1 kartotherian kartotherian 658 Jun 19 15:37 geojson-mapnikify-366f95d32dd61e41d756f9b607559f7e.png -rw-r--r-- 1 kartotherian kartotherian 658 Jun 19 15:37 geojson-mapnikify-6adbeacf95619137fd35f275a0a0061d.png -rw-r--r-- 1 kartotherian kartotherian 658 Jun 19 15:37 geojson-mapnikify-c26672b870d76b5cb0a738f5613172ec.png -rw-r--r-- 1 kartotherian kartotherian 788 Jun 19 15:37 geojson-mapnikify-13128c993c5940a5a796956be2818ad0.png -rw-r--r-- 1 kartotherian kartotherian 657 Jun 19 15:36 geojson-mapnikify-551adb79b04f4c8172b20beed07c1fe5.png drwxr-xr-x 23 root root 4096 Jun 19 09:04 .. drwx------ 3 root root 4096 Jun 19 09:02 systemd-private-e1ab9615b1264ee791e944a9a276da24-nginx.service-b8ArkX drwx------ 3 root root 4096 Jun 19 09:02 systemd-private-e1ab9615b1264ee791e944a9a276da24-systemd-timesyncd.service-X8TpLs drwxrwxrwt 2 root root 4096 Jun 19 09:02 .ICE-unix drwxrwxrwt 2 root root 4096 Jun 19 09:02 .Test-unix drwxrwxrwt 2 root root 4096 Jun 19 09:02 .X11-unix drwxrwxrwt 2 root root 4096 Jun 19 09:02 .XIM-unix drwxrwxrwt 2 root root 4096 Jun 19 09:02 .font-unix
root@maps1002:/tmp# ls -la geojson-mapnikify-* | wc -l 5000