Amazon rds MySql -> concurrent connections deadlocks I normally hang around in StackOverflow but I think this issue is better suited here.

I've built an application in C#.NET that uses MySql as a database.
My application inserts and updates data in the database in a using the Parallel API (so multithreaded). For reference, the queries that are being fired multithreaded would look like:

Update User set IsActive = 1 where UserID = 1 --each thread updates a different user id


This has always worked on servers that I manage and development machines.

We recently migrated the MySql database to Amazon RDS, however. Since then, if I run this query multithreaded (even with as low as two concurrent threads), it throws an exception:

Deadlock found when trying to get lock; try restarting transaction


Any experience with this issue? Are there some settings in Amazon RDS which are configured differently from a default MySql installation?

Thanks in advance!
The short answer is no: I can't think of a difference from MySQL defaults that would cause this.

The longer answer is that it is possible to reduce some locking with READ-COMMITTED as the isolation level + Row-based Replication. To which RDS does not support switching to Row-based Replication :(

Whether or not this reduction in locking will help you depends on your schema.  See my blog post here under "Write scalability of certain statements".