Technology is disclosed for establishing a querying system and load balancing the multi-tiered querying system. A multi-tiered targeted query system can comprise three tiers: a web tier, an aggregator tier, and a shard tier. When load balancing of shards is performed, fan-out can occur, increasing latency. The disclosed technology performs load balancing while minimizing the amount fan-out increase. Selecting the databases to move can comprise determining which databases on that server are causing the most load, and determining if moving any of these databases will increase an expected amount of fan-out above an acceptable threshold value. Determining the expected amount of fan-out increase incurred by moving a database can be based on an analysis of a number of friend relationships between that database and other databases on the same or other servers.