openstack juno version(three node setup)

ERROR ceilometer.nova_client [-] The server has either erred or is incapable of performing the requested operation. (HTTP 500) (Request-ID: req-054d0c6e-d0da-4bbe-929b-7e2cdae7cc8c)

in the log file of ceilometer-agent-compute .log`

compute .conf file on compute node

[DEFAULT] 
rpc_backend = rabbit
rabbit_host = controller
rabbit_password = XXXXXX
verbose = True
[database]
connection=sqlite:////var/lib/ceilometer/ceilometer.sqlite
[publisher]
metering_secret = METERING_SECRET
[keystone_authtoken]
...
auth_uri = http://controller:5000/v2.0
identity_uri = http://controller:35357
admin_tenant_name = service
admin_user = ceilometer
admin_password = XXXXXXXX
 [service_credentials]
...
os_auth_url = http://controller:5000/v2.0
os_username = ceilometer
os_tenant_name = service
os_password = XXXXXX
os_endpoint_type = internalURL
os_region_name = regionOne

ceilometer.conf on controller node

[DEFAULT]
verbose = true
rpc_backend = rabbit
rabbit_host = controller
rabbit_password = rabbit123
auth_strategy = keystone
log_dir=/var/log/ceilometer

[alarm]
evaluation_interval=60

[database]
connection = mongodb://ceilometer:ceilometer123@controller:27017/ceilometer

[publisher]
metering_secret = METERING_SECRET

[keystone_authtoken]
...
auth_uri = http://controller:5000/v2.0
identity_uri = http://controller:35357
admin_tenant_name = service
admin_user = ceilometer
admin_password = XXXXXXXX

[service_credentials]
os_auth_url = http://controller:5000/v2.0
os_username = ceilometer
os_tenant_name = service
os_password = ceilometer123

how to solve this issue as i am doing auto scaling , stack is creating but not able to scale. a found error in log.