Critical Description
Accessing certain paths in the master web UI during startup can cause the master to crash. For example, /dump-entities while the master tablet is still bootstrapping will lead to a CHECK crash (SysCatalogTable has an uninitialized schema at this point). There are no doubt others too.
We haven't seen this in testing because our tests generally don't access the web UI, or they don't try to bootstrap a large master tablet. We've seen at least one user hit this, though: for some reason the master tablet was enormous (i.e. it took at least a minute to bootstrap) and the Cloudera Manager agent was periodically accessing /dump-entities.