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Chapter 15. Tips for undercloud and overcloud services

This section provides advice on tuning and managing specific OpenStack services on the undercloud.

15.1. Tuning deployment performance
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Red Hat OpenStack Platform (RHOSP) director uses OpenStack Orchestration (heat) to conduct the main deployment and provisioning functions. You can use the --heat-config-vars-file option on the openstack overcloud deploy command to tune the following parameters:

debug
Run in debug mode.
log_file
Specify log file path.
max_json_body_size
Maximum raw byte size of JSON request body.
max_template_size
Maximum raw byte size of any template.
num_engine_workers
Set the number of workers. Heat uses a series of workers to execute deployment tasks. To calculate the default number of workers, the director heat configuration halves the total CPU thread count of the undercloud. In this instance, thread count refers to the number of CPU cores multiplied by the hyper-threading value. For example, if your undercloud has a CPU with 16 threads, heat spawns 8 workers by default. The director configuration also uses a minimum and maximum cap by default. The minimum is 4 and the max is 24.
rpc_response_timeout
Seconds to wait for a response from a call.

Example

  1. Create a file such as heat-overrides.yaml.

  2. Enter parameters as needed: 

    rpc_response_timeout: 1200
num_engine_workers: 24
debug: true
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  3. Include the file in an openstack overcloud deploy command: 

    $ openstack overcloud deploy \
--heat-config-vars-file heat-overrides.yaml \
--answers-file templates/answers.yaml
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If you enabled SSL/TLS in the undercloud (see Section 4.2, “Undercloud configuration parameters”), you might want to harden the SSL/TLS ciphers and rules that are used with the HAProxy configuration. This hardening helps to avoid SSL/TLS vulnerabilities, such as the POODLE vulnerability.

Set the following hieradata using the hieradata_override undercloud configuration option:

tripleo::haproxy::ssl_cipher_suite
The cipher suite to use in HAProxy.
tripleo::haproxy::ssl_options
The SSL/TLS rules to use in HAProxy.

For example, you might want to use the following cipher and rules:

  • Cipher: ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS
  • Rules: no-sslv3 no-tls-tickets

Create a hieradata override file (haproxy-hiera-overrides.yaml) with the following content: 

tripleo::haproxy::ssl_cipher_suite: ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS
tripleo::haproxy::ssl_options: no-sslv3 no-tls-tickets
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Note

The cipher collection is one continuous line.

Set the hieradata_override parameter in the undercloud.conf file to use the hieradata override file you created before you ran openstack undercloud install: 

[DEFAULT]
...
hieradata_override = haproxy-hiera-overrides.yaml
...
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