question: private int validatePreloadOrder ( CacheConfiguration [ ] cfgs ) throws IgniteCheckedException { int maxOrder = 0 ; for ( CacheConfiguration cfg : cfgs ) { int rebalanceOrder = cfg . getRebalanceOrder ( ) ; if ( rebalanceOrder > 0 ) { if ( cfg . getCacheMode ( ) == LOCAL ) throw new IgniteCheckedException ( "Rebalance order set for local cache (fix configuration and restart the " + "node): " + U . maskName ( cfg . getName ( ) ) ) ; if ( cfg . getRebalanceMode ( ) == CacheRebalanceMode . NONE ) throw new IgniteCheckedException ( "Only caches with SYNC or ASYNC rebalance mode can be set as rebalance " + "dependency for other caches [cacheName=" + U . maskName ( cfg . getName ( ) ) + ", rebalanceMode=" + cfg . getRebalanceMode ( ) + ", rebalanceOrder=" + cfg . getRebalanceOrder ( ) + ']' ) ; maxOrder = Math . max ( maxOrder , rebalanceOrder ) ; } else if ( rebalanceOrder < 0 ) throw new IgniteCheckedException ( "Rebalance order cannot be negative for cache (fix configuration and restart " + "the node) [cacheName=" + U . maskName ( cfg . getName ( ) ) + ", rebalanceOrder=" + rebalanceOrder + ']' ) ; } return maxOrder ; }
target:  Checks that preload-order-dependant caches has SYNC or ASYNC preloading mode.