Mysql – Does the Amazon RDS backup/snapshot service lock tables

The recommended way to back up RDS is with automatic backups and DB snapshots. DB snapshots are basically the same as EBS snapshots, which are stored in S3 behind the scenes, but are only available within the same region.

If you need cross-region fault tolerance (good plan!), there is no way to restore your data in another region without doing it "the hard way" from a mysqldump. Your alternatives are to back up using mysqldump (slow and terrible for any reasonable sized dataset), or set up your own EC2-based slave in another region and back that up using any available method (xtrabackup, EBS snapshots, etc). However, then you are back to managing your own MySQL instances, so you might as well abandon RDS entirely.

For my money, RDS provides absolutely no benefits in really any way and a whole lot of disadvantages in performance, flexibility, and reliability. I would ask yourself what value RDS provides to you.

Since you are running MySQL 5.5, have you considering tuning InnoDB for better performance?

There are several variables that have been added to the MySQL 5.1 InnoDB Plugin that are now native to MySQL 5.5. They usually help increase hyperthreading and take advantage of more IOPS if the environment can handled it. In your case, you should be able to.

I have spun RDS models before (See my post : Local database vs Amazon RDS) and can tell you that RDS is not very helpful in tuning InnoDB. You will have to take the bull by the horns on this one.

When you spun up the RDS instance, you probably used the default DB Parameter Group

You should be able to create a new DB Parameter Group for yourself. When you get to this, set the following:

• innodb_read_io_threads : Highest allowed is 64. In RDS, highest allowed is 16. Default is 4.
• innodb_write_io_threads : Highest allowed is 64. In RDS, highest allowed is 16. Default is 4.
• innodb_thread_concurrency : Default is already 0. Never set this value to any other number.

I suggest these because they are default in RDS for innodb_read_io_threads and innodb_write_io_threads are just too low. In addition, your SHOW ENGINE INNODB STATUS\G

--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (write thread)

only shows the default of 4 for each class of io threads.

Here is the Bad News: To implement config changes, once you create your own DB Parameter Group, you must export the data from the old RDS instance, create a new instance using your new DB Parameter Group, and reload. In more detail...

• Create a Custom DB Parameter Group (call it MySettings)
• Download RDS CLI and setup a config file with your AWS Credentials
• Execute the following : ./rds-modify-db-parameter-group MySettings --parameters "name=innodb_read_io_threads,value=16,method=immediate"
• Modify using DB Parameter Option List MySettings
• Restart the MySQL RDS Instance

I hope this helps !!!