rw-core errors when deleting OLT

{
  "level": "error",
  "ts": "2019-12-18T21:34:37.970Z",
  "msg": "failure-deleting-device-flows",
  "instanceId": "voltha-rw-core-658b894766-fsllm",
  "caller": "logical_device_agent.flowDeleteStrict:1079",
  "logicalDeviceId": "0a0a0a0a0a00",
  "error": "rpc error: code = Aborted desc = errors-[<nil> rpc error: code = Aborted desc = timeout]",
  "stacktrace": "github.com/opencord/voltha-lib-go/v2/pkg/log.Errorw\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v2/pkg/log/log.go:721\ngithub.com/opencord/voltha-go/rw_core/core.(*LogicalDeviceAgent).flowDeleteStrict\n\t/go/src/rw_core/core/logical_device_agent.go:1079\ngithub.com/opencord/voltha-go/rw_core/core.(*LogicalDeviceAgent).updateFlowTable\n\t/go/src/rw_core/core/logical_device_agent.go:532\ngithub.com/opencord/voltha-go/rw_core/core.(*LogicalDeviceManager).updateFlowTable\n\t/go/src/rw_core/core/logical_device_manager.go:519"
}
{
  "level": "error",
  "ts": "2019-12-18T21:34:37.975Z",
  "msg": "flow-delete-failedmap[deviceID:fc726cfe34ed814ff957a8f7 error:rpc error: code = Aborted desc = errors-[rpc error: code = Canceled desc = context deadline exceeded]]",
  "instanceId": "voltha-rw-core-658b894766-fsllm",
  "caller": "logical_device_agent.func1:989",
  "stacktrace": "github.com/opencord/voltha-lib-go/v2/pkg/log.Error\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v2/pkg/log/log.go:705\ngithub.com/opencord/voltha-go/rw_core/core.(*LogicalDeviceAgent).deleteDeviceFlowsAndGroups.func1\n\t/go/src/rw_core/core/logical_device_agent.go:989"
}
{
  "level": "error",
  "ts": "2019-12-18T21:34:38.102Z",
  "msg": "loading-device-failed",
  "instanceId": "voltha-rw-core-658b894766-fsllm",
  "caller": "device_manager.getDeviceAgent:141",
  "deviceId": "b0a0cc383219bfdcb94cd789",
  "error": "rpc error: code = Aborted desc = Error loading device b0a0cc383219bfdcb94cd789",
  "stacktrace": "github.com/opencord/voltha-lib-go/v2/pkg/log.Errorw\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v2/pkg/log/log.go:721\ngithub.com/opencord/voltha-go/rw_core/core.(*DeviceManager).getDeviceAgent\n\t/go/src/rw_core/core/device_manager.go:141\ngithub.com/opencord/voltha-go/rw_core/core.(*DeviceManager).deleteFlowsAndGroups\n\t/go/src/rw_core/core/device_manager.go:753\ngithub.com/opencord/voltha-go/rw_core/core.(*LogicalDeviceAgent).deleteDeviceFlowsAndGroups.func1\n\t/go/src/rw_core/core/logical_device_agent.go:988"
}