- * - groupLoadsByDB 3-d map giving server load ratios by DB name.
- * - hostsByName Map of hostname to IP address.
- * - externalLoads Map of external storage cluster name to server load map.
- * - externalTemplateOverrides Set of server configuration maps overriding
- * "serverTemplate" for external storage.
- * - templateOverridesByServer 2-d map overriding "serverTemplate" and
- * "externalTemplateOverrides" on a server-by-server basis.
- * Applies to both core and external storage.
- * - templateOverridesBySection 2-d map overriding the server configuration maps by section.
- * - templateOverridesByCluster 2-d map overriding the server configuration maps by external
- * storage cluster.
- * - masterTemplateOverrides Server configuration map overrides for all master servers.
- * - loadMonitorClass Name of the LoadMonitor class to always use.
- * - readOnlyBySection A map of section name to read-only message.
- * Missing or false for read/write.
+ * - groupLoadsByDB Optional (database => group => host => load ratio) map.
+ * - externalLoads Optional (cluster => host => load ratio) map.
+ * - serverTemplate server config map for Database::factory().
+ * Note that "host", "hostName" and "load" entries will be
+ * overridden by "groupLoadsBySection" and "hostsByName".
+ * - externalTemplateOverrides Optional server config map overrides for external
+ * stores; respects the override precedence described above.
+ * - templateOverridesBySection Optional (section => server config map overrides) map;
+ * respects the override precedence described above.
+ * - templateOverridesByCluster Optional (external cluster => server config map overrides)
+ * map; respects the override precedence described above.
+ * - masterTemplateOverrides Optional server config map overrides for masters;
+ * respects the override precedence described above.
+ * - templateOverridesByServer Optional (host => server config map overrides) map;
+ * respects the override precedence described above
+ * and applies to both core and external storage.
+ * - loadMonitorClass Name of the LoadMonitor class to always use. [optional]
+ * - readOnlyBySection Optional map of (section name => message text or false).
+ * String values make sections read only, whereas anything
+ * else does not restrict read/write mode.