1. timeout
timeout：默认无timeout，latency平衡completeness，
手动指定timeout：
timeout=10ms，timeout=1s，timeout=1m
GET blant/_search?timeout=1s2. timeout机制
指定timeout，就能在timeout时间范围内，将搜索到的部分数据（也可能全部都搜索到），直接返回给client，而不是所有数据搜索到再返回，可以为一些敏感的搜索应用提供良好的支持。
3. 例子
GET bank/_search?timeout=1s结果
{"took" : 1,"timed_out" : false,"_shards" : {"total" : 1,"successful" : 1,"skipped" : 0,"failed" : 0},"hits" : {"total" : {"value" : 1000,"relation" : "eq"},"max_score" : 1.0,"hits" : [{"_index" : "bank","_type" : "account","_id" : "1","_score" : 1.0,"_source" : {"account_number" : 1,"balance" : 39225,"firstname" : "Amber","lastname" : "Duke","age" : 32,"gender" : "M","address" : "880 Holmes Lane","employer" : "Pyrami","email" : "amberduke@pyrami.com","city" : "Brogan","state" : "IL"}},hits.total 本次搜索返回几条结果
hits.max_score：本次搜索的所有的结果中，最大的相关度分数是多少
hits.hits:默认查询前10条数据，完整数据，_score降序