该示例使用基本的HTTP语法。<#>复制示例时，应删除示例中的所有内容。
像_catElasticsearch中的大多数API一样，API有选择地响应默认字段集。但是，如果需要，API中还存在其他字段：
GET /_cat/health?help <1>
?help 使API返回字段（和简称）以及简短说明。
_cat/health 从Elasticsearch 1.x开始存在，但是这里是Elasticsearch 5.x输出的示例：
此示例创建日期之前可用的字段：
epoch | t,time | seconds since 1970-01-01 00:00:00 timestamp | ts,hms,hhmmss | time in HH:MM:SS cluster | cl | cluster name status | st | health status node.total | nt,nodeTotal | total number of nodes node.data | nd,nodeData | number of nodes that can store data shards | t,sh,shards.total,shardsTotal | total number of shards pri | p,shards.primary,shardsPrimary | number of primary shards relo | r,shards.relocating,shardsRelocating | number of relocating nodes init | i,shards.initializing,shardsInitializing | number of initializing nodes unassign | u,shards.unassigned,shardsUnassigned | number of unassigned shards pending_tasks | pt,pendingTasks | number of pending tasks max_task_wait_time | mtwt,maxTaskWaitTime | wait time of longest task pending active_shards_percent | asp,activeShardsPercent | active number of shards in percent
然后，您可以使用它仅打印那些字段：
GET /_cat/health?h=timestamp,cl,status&v <1>
h=... 定义要返回的字段列表。
v （详细）定义您希望它打印标题。
Elasticsearch 5.x实例的输出：
timestamp cl status 15:38:00 elasticsearch yellow