Update worker threads to better optimize gate memory

This change updates our worker section so that we're not spawning so may
worker threads in the AIO. This simple change allows us to save quite a
bit of memory which is extremely important when running in an resource
constrained environment.

Example Before:
              total        used        free      shared  buff/cache   available
Mem:            15G        8.3G        295M        422M        7.1G        6.5G
Swap:          1.0G         14M        1.0G

Example After:
              total        used        free      shared  buff/cache   available
Mem:            15G        5.6G        4.4G        458M        5.7G        9.1G
Swap:          1.0G         13M        1.0G

Change-Id: I001d67423e0ba7196c536e2d3fad616604842a40
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

tests/roles/bootstrap-host/templates/user_variables.aio.yml.j2

@@ -21,32 +21,121 @@ tempest_public_subnet_cidr: 172.29.248.0/22
 tempest_public_subnet_allocation_pools: "172.29.249.110-172.29.249.200"
 
 ## Galera settings
-galera_innodb_buffer_pool_size: 256M
-galera_innodb_log_buffer_size: 32M
+galera_innodb_buffer_pool_size: 16M
+galera_innodb_log_buffer_size: 4M
 galera_wsrep_provider_options:
- - { option: "gcache.size", value: "32M" }
+ - { option: "gcache.size", value: "4M" }
 
 ## Neutron settings
 neutron_metadata_checksum_fix: True
 
-## Set workers for all services to optimise memory usage
-ceilometer_notification_workers: 2
-cinder_osapi_volume_workers: 2
-glance_api_threads: 2
-heat_api_threads: 2
-horizon_wsgi_processes: 2
-horizon_wsgi_threads: 2
-keystone_wsgi_processes: 2
-neutron_api_workers: 2
-neutron_metadata_workers: 1
-neutron_rpc_workers: 1
-nova_api_threads: 2
-nova_wsgi_processes: 2
+### Set workers for all services to optimise memory usage
+
+## Repo
 repo_nginx_threads: 2
-swift_account_server_workers: 2
-swift_container_server_workers: 2
-swift_object_server_workers: 2
-swift_proxy_server_workers: 2
+
+## Keystone
+keystone_httpd_mpm_start_servers: 2
+keystone_httpd_mpm_min_spare_threads: 1
+keystone_httpd_mpm_max_spare_threads: 2
+keystone_httpd_mpm_thread_limit: 2
+keystone_httpd_mpm_thread_child: 1
+keystone_wsgi_threads: 1
+keystone_wsgi_processes_max: 2
+
+## Barbican
+barbican_wsgi_processes: 2
+barbican_wsgi_threads: 1
+
+## Cinder
+cinder_wsgi_processes_max: 2
+cinder_wsgi_threads: 1
+cinder_wsgi_buffer_size: 16384
+cinder_osapi_volume_workers_max: 2
+
+## Glance
+glance_api_threads_max: 2
+glance_api_threads: 1
+glance_api_workers: 1
+glance_registry_workers: 1
+
+## Nova
+nova_wsgi_threads: 1
+nova_wsgi_processes_max: 2
+nova_wsgi_processes: 2
+nova_wsgi_buffer_size: 16384
+nova_api_threads_max: 2
+nova_api_threads: 1
+nova_osapi_compute_workers: 1
+nova_conductor_workers: 1
+nova_metadata_workers: 1
+
+## Neutron
+neutron_rpc_workers: 1
+neutron_metadata_workers: 1
+neutron_api_workers: 1
+neutron_api_threads_max: 2
+neutron_api_threads: 2
+neutron_num_sync_threads: 1
+
+## Heat
+heat_api_workers: 1
+heat_api_threads_max: 2
+heat_api_threads: 1
+heat_wsgi_threads: 1
+heat_wsgi_processes_max: 2
+heat_wsgi_processes: 1
+heat_wsgi_buffer_size: 16384
+
+## Horizon
+horizon_wsgi_processes: 1
+horizon_wsgi_threads: 1
+horizon_wsgi_threads_max: 2
+horizon_wsgi_threads: 1
+
+## Ceilometer
+ceilometer_notification_workers_max: 2
+ceilometer_notification_workers: 1
+
+## AODH
+aodh_wsgi_threads: 1
+aodh_wsgi_processes_max: 2
+aodh_wsgi_processes: 1
+
+## Gnocchi
+gnocchi_wsgi_threads: 1
+gnocchi_wsgi_processes_max: 2
+gnocchi_wsgi_processes: 1
+
+## Swift
+swift_account_server_replicator_workers: 1
+swift_server_replicator_workers: 1
+swift_object_replicator_workers: 1
+swift_account_server_workers: 1
+swift_container_server_workers: 1
+swift_object_server_workers: 1
+swift_proxy_server_workers_max: 2
+swift_proxy_server_workers_not_capped: 1
+swift_proxy_server_workers_capped: 1
+swift_proxy_server_workers: 1
+
+## Ironic
+ironic_wsgi_threads: 1
+ironic_wsgi_processes_max: 2
+ironic_wsgi_processes: 1
+
+## Trove
+trove_api_workers_max: 2
+trove_api_workers: 1
+trove_conductor_workers_max: 2
+trove_conductor_workers: 1
+trove_wsgi_threads: 1
+trove_wsgi_processes_max: 2
+trove_wsgi_processes: 1
+
+## Sahara
+sahara_api_workers_max: 2
+sahara_api_workers: 1
 
 # NOTE: hpcloud-b4's eth0 uses 10.0.3.0/24, which overlaps with the
 #       lxc_net_address default