Chapter 9

1. Yes. It is recommended that you have an active-passive or active-active database so that in the event of failures, you can easily switch database instances. Note, however, that Keycloak keeps as much data as possible in caches, where reads should not be impacted at all depending on how hot the caches are (how much data is cached). Writes, however, will fail until the connection is re-established. Keycloak also supports setting some useful configuration options to improve failover in the event of network failures. You might want to enable background validation of connections to make sure available connections are usable, validate connections prior to obtaining them from the connection pool, or even configure the pool to fail fast when a connection is terminated to avoid validating and iterating over all connections in the pool.
2. No. The default configuration uses IP multicast to broadcast messages across nodes and form a cluster. The proper configuration depends...