Performance: Do not queue no-op destroy action

[isimluk]

What?

1. Avoid the queue overhead, i.e. worker_queue_lock, sql (insert, selects, updates, deletes) of this queue item

2. Avoid the log overhead (lock, sync, etc).

3. Profit

Previously we did this:

SQL (0.3ms)  INSERT INTO "miq_queue" ("priority", "method_name", "state", "created_on", "updated_on", "queue_name", "class_name", "args", "zone", "msg_timeout", "lock_version") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11) RETURNING "id"  [["priority", 100], ["method_name", "destroy"], ["state", "ready"], ["created_on", 2017-05-12 12:48:26 UTC], ["updated_on", 2017-05-12 12:48:26 UTC], ["queue_name", "generic"], ["class_name", "MiqTask"], ["args", "---\n- []\n"], ["zone", "default"], ["msg_timeout", 600], ["lock_version", 0]]

Note this gets called quite often with empty ids. Just grep your logs ;-)

[chessbyte]

@isimluk please fix failing tests

[miq-bot]

Checked commits isimluk/manageiq@ff93136~...12e4b60 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
2 files checked, 0 offenses detected
Everything looks fine. 🏆