Depends entirely on the type of project and the data. Data that models easily via sql? Percona Xtradb Cluster works pretty well. Data that models better as a

Depends entirely on the type of project and the data. Data that models easily via sql? Percona Xtradb Cluster works pretty well. Data that models better as a hierarchy of objects? OpenLDAP is pretty amazing. But a project using either of those is likely to also use eg redis+qless for processing out of band tasks. If it’s a utility that needs to store some data it might use SQLite. My point is that understanding how various options can be used is likely to give a better result than just having a “goto” square peg and hammering it into every hole you find, regardless of shape.