The problem might be known to all of you. If shut down my nodes one after the other, the last node leaving the cluster (host v1 in our case) should be the first booting up in order the provide CCR consistency.However, it that node refuses to start up (because of some HW error), I am in trouble: all the other nodes stuck in a "attempting to join cluster", since the quorum key on the quorum device belongs to v1 (the last node).So did we have to wait since the first one repaired? Not really, here is a solution. more »

Running multiple instances of the same binary of mysql is not a big deal. However trying to install and run mysql 5.0, 5.1 and 5.5 on the same machine... that's somewhat more tricky. more »

A common problem for transactional databases to identify what some transactions/thread waiting for.With MYISAM, where we could use table locks only, that is quite easy. For innodb, with row (or rather page) locks it is much harder. more »

In a metropolitan cluster a single node failure cases the death of the mirrored volumes, even is the half of the replicas, mediators and disks are available more »