Remove obsolete code that significantly slows down dcorch startup

[Kyle MacLeod]

Brief Description
The software version check in IdentitySyncThread is no longer relevant and needs to be removed. It slows down dcorch-engine startup significantly
https://opendev.org/starlingx/distcloud/src/commit/388b82609185479bc7aae8cda70c0784d5a465a7/distributedcloud/dcorch/engine/sync_services/identity.py#L69

Severity
Major

Steps to Reproduce
Profile dcorch-engine startup

Expected Behavior
Speedy startup

Actual Behavior
Identity sync thread initialization is slowed down considerably because of version check. This is more apparent in large lab.

Reproducibility
100% reproducible

System Configuration
Distributed Cloud

Load info (eg: 2022-03-10_20-00-07)
Starlingx master from 2022-06-05

Last Pass
N/A

Timestamp/Logs
2022-06-06 20:15:33.968 1221364 INFO dcorch.engine.generic_sync_manager [req-a03d705a-12eb-4260-b53f-0dec5f385627 - - - - -] Engine id:(936e0ff3-a9e7-484a-9ae6-230aead39b2d) init_from_db: 1108.756395 sec │2022-06-06 20:15:36.871 1221365 INFO dcorch.engine.generic_sync_manager [req-9644733a-5b16-4a08-bc68-d987b8910d95 - - - - -] Engine id:(b03319f8-3f91-420b-b207-39b86cbf94ef) init_from_db: 1111.564746 sec │2022-06-06 20:16:13.310 1221367 INFO dcorch.engine.generic_sync_manager [req-2bbda3b2-3d96-4372-9588-2f5c12ea3235 - - - - -] Engine id:(d75460c5-375c-4008-ade0-bf1e4b704162) init_from_db: 1148.009681 sec │2022-06-06 20:17:38.614 1221363 INFO dcorch.engine.generic_sync_manager [req-944f51e3-9f79-474d-b259-7cea0d3a1e6e - - - - -] Engine id:(35afc79e-a22c-48f4-ac61-6d948f7f2d0d) init_from_db: 1233.311176 sec │2022-06-06 20:17:38.746 1221366 INFO dcorch.engine.generic_sync_manager [req-2df03a7e-c1c2-441b-9861-8fe6e4b7bb1c - - - - -] Engine id:(29634af2-3a25-4e13-afbb-239ce6875090) init_from_db: 1233.43956 sec │

Alarms
N/A

Test Activity
Developer Testing

Workaround
N/A

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/distcloud/+/845165

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/distcloud/+/845165
Committed: https://opendev.org/starlingx/distcloud/commit/c6be0604ed00ec47d7245fc9367e4f3e67f6447b
Submitter: "Zuul (22348)"
Branch: master

commit c6be0604ed00ec47d7245fc9367e4f3e67f6447b
Author: Kyle MacLeod <email address hidden>
Date: Wed Jun 8 13:53:49 2022 -0400

    Remove obsolete software_version check

    Remove the check for 21.05 software_version in __init__.
    This removes the need to obtain the as-yet uncached
    OpenStackDriver instance for every subcloud during startup.
    On a large system this significantly reduces the startup
    time spent in GenericSyncManager init_from_db()

    Test Plan:

    PASS:

    Verify normal startup and initialization via GenericSyncManager
    - Verified on StarlingX master load as well as on patched 21.12 load

    Verify startup on large system
    - Startup time is reduced from many minutes down to 2s

    Before/After on a large DC system from generic_sync_manager:

    Engine id:(c8816967-1c87-4e32-a1e2-8b900d97878e) init_from_db finished
    [1109.9s]

    Engine id:(58c49ff0-181b-435b-b0fc-bf20ecbf4498) init_from_db finished
    [2.7s]

    Closes-Bug: 1977994

    Signed-off-by: Kyle MacLeod <email address hidden>
    Change-Id: I2ba1fee039d7e9fa7ba6094a020c96932e013b30