Documentation for new Database Pooling configs #3
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matthewd
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We should still avoid using them whenever possible, but e.g. I'd like to be able to break connections inside a pool test.
The shared setup method creates a connection pool, and having the isolation level change after a pool is created makes things awkward. This has slightly more duplication, but not enough that I feel the need to seek a different abstraction.
In the process, be more consistent about always disconnecting pools we've created.
Building upon the "checkout for maintenance" primitives, this gives us a method to progressively loop over idle connections without the risk of starving the pool while we work. Even for something internal, I don't love the API... but hopefully it will suffice until we come up with something better.
Co-authored-by: Chris AtLee <[email protected]>
Co-authored-by: Chris AtLee <[email protected]>
Optionally ensure the full database connection chain sees regular query traffic (without affecting our internal idle counters).
Avoid using database connections that were originally established over the configured duration ago. This can be helpful to provide smooth failover between connection proxies.
This is ideal where the caller knows that a database server/proxy failover is occurring (meaning that previously-established connections are now potentially pointing to the wrong place, and new fresh connections will go to the right one); where such signalling is possible, it can be used in place of an onerously low / "preventative" max_age.
It's less elegant, but just seems easier to reason about.
…ctions Co-authored-by: Matthew Draper <[email protected]>
Co-authored-by: Matthew Draper <[email protected]>
Co-authored-by: Matthew Draper <[email protected]>
ChaelCodes
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ChaelCodes
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| <!-- Suggestions please --> | ||
| Idle database connections can be bad - the database may no longer exist, or | ||
| may assume the application server no longer exists. `keepalive` will check | ||
| open database connections and keep them alive. | ||
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| <!-- How does this interact with idle_timeoue? --> | ||
| <!-- How does this interact with min_connections? --> | ||
| <!-- How does this interact with INFINITY? --> |
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cc @matthewd
Hi, could you kindly offer some suggestions or thoughts on how these configurations interact with each other?
Maybe some of these details could/should be moved to https://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/ConnectionPool.html ?
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Motivation / Background
This Pull Request updates the guides to reflect the changes introduced in rails#54175.
Checklist
Before submitting the PR make sure the following are checked:
[Fix #issue-number]