The WiredTiger cache overflow mechanism (lookaside) has not been optimized for throughput. Once cache overflow is being used, WiredTiger should aim to minimize it's performance consequences (which will be significant).

One aspect of this would be to ensure that reading/writing to disk can saturate the I/O channel.

This work consists of:

• Construct a multi-threaded workload that makes heavy ongoing use of lookaside.
• Optimize the lookaside implementation until the workload is constrained by the I/O capacity of the system when using a fast disk.