Comment 3 for bug 1243251

i put some logging to capture sessions in my environment: http://paste.openstack.org/show/49269/

from the looks of it, ceilometer is releasing sessions after meters are recorded, its just that Tempest tests are opening sessions quicker than previous sessions are released so eventually we're exhausting the default pool size. we could rework the sql model so we can write quicker or add sharding support... but is there a way to increase pool size for devstack setup? seems more a configuration problem rather than Ceilometer bug right now (although we do need to improve performance to handle high volume environments)