How to make solr fault tolerant for query?

[Amey Jadiye]

Just a dumb question but how can i make solr cloud fault tolerant for queries ? 
why i am asking this question because, i have 12 different physical server and 
i am running  12 solr shards on that, whenever any one of them is going down 
because of any reason it gives me below error, i have 3 zookeeper for 12 
servers all are leader and no replica for this solr cloud.
I have option of using shards.tolerant=true  but this is slow and dont gives 
all results.
Best,Amey
{
  "responseHeader": {
    "status": 503,
    "QTime": 7,
    "params": {
      "sort": "last_modified asc",
      "indent": "true",
      "q": "+links:[* TO *]",
      "_": "1410512274068",
      "wt": "json"
    }
  },
  "error": {
    "msg": "no servers hosting shard: ",
    "code": 503
  }
}