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A driver forQueues. UsesFluent to store job metadata in an SQL database.

This package makes use of theSKIP LOCKED feature supported by some of the major database engines (most notablyPostgresSQL andMySQL) when available to make a best-effort guarantee that a task or job won't be picked by multiple workers.

This package should be compatible with any SQL database supported by the various Fluent drivers. It is specifically known to work with:

• PostgreSQL 11.0+
• MySQL 5.7+
• MariaDB 10.5+
• SQLite

AddQueuesFluentDriver as dependency to yourPackage.swift:

dependencies:[.package(url:"https://github.com/vapor-community/vapor-queues-fluent-driver.git", from:"3.0.0-beta.4"),...]

AddQueuesFluentDriver to the target you want to use it in:

targets:[.target(name:"MyFancyTarget", dependencies:[.product(name:"QueuesFluentDriver",package:"vapor-queues-fluent-driver"),])]

This package includes a migration to create the database table which holds job metadata; add it to your Fluent configuration as you would any other migration:

app.migrations.add(JobModelMigration())

Finally, load theQueuesFluentDriver driver:

app.queues.use(.fluent())

You can optionally create a dedicated non-defaultDatabase with a customDatabaseID for use with your queues, as in the following example:

extensionDatabaseID{staticvarqueues:Self{.init(string:"my_queues_db")}}func configure(_ app:Application)asyncthrows{    app.databases.use(.postgres(configuration:...), as:.queues, isDefault:false)    app.queues.use(.fluent(.queues))}

By default, the Vapor Queues system starts 2 workers per available CPU core, with each worker would polling the database once per second. On a 4-core system, this would results in 8 workers querying the database every second. Most configurations do not need this many workers. Additionally, when using SQLite as the underlying database it is generally inadvisable to run more than one worker at a time, as SQLite does not have the .

The polling interval can be changed using therefreshInterval configuration setting:

app.queues.configuration.refreshInterval=.seconds(5)

Likewise, the number of workers to start can be changed via theworkerCount setting:

app.queues.configuration.workerCount=1