说下shard出现的几个状态说明：

• relocating_shards shows the number of shards that are currently moving from one node to another node(现网中遇到，因为kill -9重启es的方法不对，导致node下线，集群重新分配shard). This number is often zero, but can increase when Elasticsearch decides a cluster is not properly balanced, a new node is added, or a node is taken down, for example（我们的ES集群没有副本，很可能由于网络不稳定导致单个节点下线，从而重新分配shard）.
• initializing_shards is a count of shards that are being freshly created. For example, when you first create an index, the shards will all briefly reside in initializing state. This is typically a transient event, and shards shouldn’t linger in initializing too long. You may also see initializing shards when a node is first restarted: as shards are loaded from disk, they start as initializing.（现网遇到过）
• unassigned_shards are shards that exist in the cluster state, but cannot be found in the cluster itself. A common source of unassigned shards are unassigned replicas. For example, an index with five shards and one replica will have five unassigned replicas in a single-node cluster. Unassigned shards will also be present if your cluster is red (since primaries are missing).

其中unassigned_shards的问题是比较头痛的，我汇总了网上的解决方法，大家后面遇到可以参阅：

总结得最整的是 

单独针对主shard出现unassigned的解决可以看   

单独针对副本shard出现unassigned的解决可以看   

本文转自张昺华-sky博客园博客，原文链接：http://www.cnblogs.com/bonelee/p/7459509.html，如需转载请自行联系原作者