During my profiling of C* I frequently see lots of aggregate time across threads being spent inside the MD5 MessageDigest implementation. Given that there are tons of modern alternative hashing functions better than MD5 available – both in terms of providing better collision resistance and actual computational speed – I wanted to switch out our usage of MD5 for alternatives (like adler128 or murmur3_128) and test for performance improvements.
Unfortunately, I found given the fact we use MessageDigest everywhere – switching out the hashing function to something like adler128 or murmur3_128 (for example) – which don't ship with the JDK – wasn't straight forward.
The goal of this ticket is to propose switching out usages of MessageDigest directly in favor of Hasher from Guava. This means going forward we can change a single line of code to switch the hashing algorithm being used (assuming there is an implementation in Guava).