Stop retrying semaphore decrement when getting a deadlock #152
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This was added in d72fe46 and initially, it seemed like a good idea, but it ended up causing a different error as it messed with Active Record's transactions. The error would be ``` ActiveRecord::StatementInvalid (Mysql2::Error: SAVEPOINT active_record_1 does not exist) ``` And this made us realise it might be more complicated, because we might be in a transaction that wraps the Solid Queue transaction. Since this is such an edge case that happens only with certain job loads and perhaps only with MySQL, InnoDB and READ COMMITTED, let's stop trying to be too clever about it, and instead, simplify this a bit by avoiding the decrement at all when the semaphore's limit is 1 and it was just created.
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This was added in d72fe46 and initially, it seemed like a good idea, but it ended up causing a different error as it messed with Active Record's transactions. The error would be
And this made us realise it might be more complicated, because we might be in a transaction that wraps the Solid Queue transaction.
Since this is such an edge case that happens only with certain job loads and perhaps only with MySQL, InnoDB and READ COMMITTED, let's stop trying to be too clever about it, and instead, simplify this a bit by avoiding the decrement at all when the semaphore's limit is 1 and it was just created.