--- features: - OSProfiler support was added. This cross-project profiling library allows to trace various OpenStack requests through all OpenStack services that support it. To initiate OpenStack request tracing `--profile ` option needs to be added to the CLI command. This key needs to present one of the secret keys defined in nova.conf configuration file with `hmac_keys` option under the `[profiler]` configuration section. To enable or disable Nova profiling the appropriate `enabled` option under the same section needs to be set either to `True` or `False`. By default Nova will trace all API and RPC requests, but there is an opportunity to trace DB requests as well. For this purpose `trace_sqlalchemy` option needs to be set to `True`. As a prerequisite OSProfiler library and its storage backend needs to be installed to the environment. If so (and if profiling is enabled in nova.conf) the trace can be generated via following command, for instance - `$ nova --profile SECRET_KEY boot --image --flavor `. At the end of output there will be message with , and to plot nice HTML graphs the following command should be used - `$ osprofiler trace show --html --out result.html` security: - OSProfiler support requires passing of trace information between various OpenStack services. This information is securely signed by one of HMAC keys, defined in nova.conf configuration file. To allow cross-project tracing user should use the key, that is common among all OpenStack services he or she wants to trace.