[18.0][ADD] queue_job: per DB channel managers with UI configuration and hot reload

[guewen]

#765 (comment)

With this in the config file, the job runner uses the static server-side configuration as before, with no hot-reload (single, shared channel manager):

[queue_job]
channels = root:10,root.p1:2

With this in the config file, the job runner uses the channels configured in the database (the job runner builds one channel manager per database):

[queue_job]
max_capacity = 10

When capacity or other options of a channel (or channels are created/deleted, paused) change, the channel manager for the concerned database is hot reloaded.

Capacity can be constrained by database:

[queue_job]
max_capacity = 10
db_max_capacity = 2

Or with patterns

[queue_job]
max_capacity = 10
db_max_capacity = prod_*:6,staging:3,*:1

When db_max_capacity is not configured, each database gets a max capacity of the global max_capacity.
When there is more jobs pending than max_capacity across the databases, a round-robin allows each database to enqueue jobs in turns.

The channels option for server-side configuration takes precedence over the new configuration.

Using this, I can, for instance

• Pause and resume a channel
• Create a new channel, assign a job function this channel, set a capacity at 1 or sequential, all from the UI and applied live by the job runner

Migration path

Since the server-side configuration (ODOO_QUEUE_JOB_CHANNELS or channels in config file) is used by default, updating the addon has no effect. It allows to configure the channels capacity and other options on the UI / by script of the databases, then the server-side configuration can be replaced by the parameters max_capacity and db_max_capacity (or their environment variables counterparts).

[OCA-git-bot]

Hi @sbidoul,
some modules you are maintaining are being modified, check this out!