code: public TenantDefinition getDefaultTenantDef() {
          if (!getState().isRunning()) {
              return createDefaultTenantDefinition();
          }
          TenantDefinition tenantDef = getTenantDef(m_defaultTenantName);
          if (tenantDef == null) {
              throw new RuntimeException("Default tenant definition is missing: " + m_defaultTenantName);
          }
          return tenantDef;
      }
docs: Get the TenantDefinition for the default tenant. If the DBService has not yet
  reached the running state, we cannot read the default tenant definition from the
  database, in which case we create a TenantDefinition based on configuration
  parameters. This allows certain system commands such as "GET /_logs" to succeed
  before the initial DB connection is established. Once the DB connection has been
  created, we read the tenant definition from the Tenants table.
  
  @return  The {@link TenantDefinition} for the default tenant.