Some interesting performance related articles and links I've come across in the past few weeks:
A useful thread discussing Voldemort's performance compared to Cassandra. Even more interesting to note is that LinkedIn runs 18G heaps for Voldemort+BDB.
HBase guys doing some work around the JVM GC, reminiscent of arenas and slab allocators.
Java Fast Sockets - a research project around alternative, high performance socket implementations for Java and its spin-off company. The company site still looks like it's in stealth mode. A downloadable version would've been nice. A "free" version would've been nicer.
If you thought Java Classloading was tricky and JVM startup times are better these days - look at what the Firefox and Chrome guys have been up to - bypassing normal DLL loading and pre-fetching pages from disk:
Another interesting read about how debuggers work internally.
Yes to SQL:
Some libraries and notes for SQL sharding and replication: