elasticsearch _cat命令详解 （秒懂+史上最全）

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---

背景：

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• 高可用、高并发nginx架构的原理与实操

• 高可用、高并发mysql架构的原理与实操

• 高可用、高并发nacos架构的原理与实操

• 高可用、高并发rocketmq架构的原理与实操

• 高可用、高并发es架构的原理与实操

• 高可用、高并发minio架构的原理与实操

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本系列博客的具体内容，请参见 Java 高并发 发烧友社群：疯狂创客圈

ES-cat相关命令汇总

_cat/allocation         #查看单节点的shard分配整体情况
_cat/shards          #查看各shard的详细情况
_cat/shards/{index}     #查看指定分片的详细情况
_cat/master          #查看master节点信息
_cat/nodes           #查看所有节点信息
_cat/indices         #查看集群中所有index的详细信息
_cat/indices/{index}      #查看集群中指定index的详细信息
_cat/segments        #查看各index的segment详细信息,包括segment名, 所属shard, 内存(磁盘)占用大小, 是否刷盘
_cat/segments/{index}#查看指定index的segment详细信息
_cat/count           #查看当前集群的doc数量
_cat/count/{index}   #查看指定索引的doc数量
_cat/recovery        #查看集群内每个shard的recovery过程.调整replica。
_cat/recovery/{index}#查看指定索引shard的recovery过程
_cat/health          #查看集群当前状态：红、黄、绿
_cat/pending_tasks   #查看当前集群的pending task
_cat/aliases         #查看集群中所有alias信息,路由配置等
_cat/aliases/{alias} #查看指定索引的alias信息
_cat/thread_pool     #查看集群各节点内部不同类型的threadpool的统计信息,
_cat/plugins         #查看集群各个节点上的plugin信息
_cat/fielddata       #查看当前集群各个节点的fielddata内存使用情况
_cat/fielddata/{fields}     #查看指定field的内存使用情况,里面传field属性对应的值
_cat/nodeattrs              #查看单节点的自定义属性
_cat/repositories           #输出集群中注册快照存储库
_cat/templates              #输出当前正在存在的模板信息

Cat 命令公共参数

• Help 查看帮助

GET _cat/master?help

id   |   | node id    
host | h | host name  
ip   |   | ip address 
node | n | node name   

• Verbose 显示列名

GET _cat/master?v

id                     host  ip              node
AhlyPtZYTta1AVH_7mUSbQ node1 192.168.113.101 master-1

• Headers 只显示特定列

GET _cat/master?v&h=host,ip,node

host  ip              node
node1 192.168.113.101 master-1

• 数字格式化

bytes=kb store.size以kb输出

GET _cat/indices?v&h=index,docs.count,store.size&bytes=kb

index                           docs.count store.size
.monitoring-es-6-2018.08.25            441        721
.monitoring-kibana-6-2018.08.25         18        205
.kibana                                  1          7
.security-6                              3         19

• Format 输出格式

##支持的输出格式有json,test,yaml等
##默认以text格式输出
##以json格式输出 format=json&pretty

GET _cat/indices?v&h=index,docs.count,store.size&bytes=kb&format=json&pretty

[
  {
    "index": ".monitoring-es-6-2018.08.25",
    "docs.count": "476",
    "store.size": "1114"
  },
  {
    "index": ".monitoring-kibana-6-2018.08.25",
    "docs.count": "21",
    "store.size": "72"
  },
  {
    "index": ".kibana",
    "docs.count": "1",
    "store.size": "7"
  },
  {
    "index": ".security-6",
    "docs.count": "3",
    "store.size": "19"
  }
]

##以yaml格式输出 format=yaml&pretty
GET _cat/indices?v&h=index,docs.count,store.size&bytes=kb&format=yaml&pretty

---
- index: ".monitoring-es-6-2018.08.25"
  docs.count: "509"
  store.size: "979"
- index: ".monitoring-kibana-6-2018.08.25"
  docs.count: "24"
  store.size: "142"
- index: ".kibana"
  docs.count: "1"
  store.size: "7"
- index: ".security-6"
  docs.count: "3"
  store.size: "19"

• Sort 排序

##按index升序，docs.count降序
GET _cat/indices?v&h=index,docs.count,store.size&bytes=kb&format=json&pretty&s=index,docs.count:desc

[
  {
    "index": ".kibana",
    "docs.count": "1",
    "store.size": "7"
  },
  {
    "index": ".monitoring-es-6-2018.08.25",
    "docs.count": "608",
    "store.size": "1068"
  },
  {
    "index": ".monitoring-kibana-6-2018.08.25",
    "docs.count": "33",
    "store.size": "163"
  },
  {
    "index": ".security-6",
    "docs.count": "3",
    "store.size": "19"
  }
]

查看集群健康状态

GET _cat/health?v&h=cluster,status

cluster status
my-elk  green

查看集群节点和磁盘剩余

##集群节点
GET _cat/nodes?v

ip              heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
192.168.113.103           60          93   5    0.54    0.53     0.55 di        -      data-2
192.168.113.104           12          87   7    0.72    0.77     0.94 -         -      client-1
192.168.113.101           13          90   4    0.35    0.32     0.37 m         *      master-1
192.168.113.102           46          91 100    2.81    2.84     3.44 di        -      data-1

##磁盘剩余
GET _cat/nodes?v&h=ip,node.role,name,disk.avail

ip              node.role name     disk.avail
192.168.113.102 di        data-1        2.4gb
192.168.113.103 di        data-2        6.5gb
192.168.113.104 -         client-1        5gb
192.168.113.101 m         master-1      6.5gb

查看集群master节点

GET _cat/master?v

id                     host  ip              node
AhlyPtZYTta1AVH_7mUSbQ node1 192.168.113.101 master-1

查看分配

##查看每个数据节点上的分片数(shards)，以及每个数据节点磁盘剩余
GET _cat/allocation?v

shards disk.indices disk.used disk.avail disk.total disk.percent host  ip              node
     4        8.2mb      14gb      3.2gb     17.2gb           81 node2 192.168.113.102 data-1
     4        5.7mb     9.9gb      7.3gb     17.2gb           57 node3 192.168.113.103 data-2

查看被挂起任务

GET _cat/pending_tasks?v

insertOrder timeInQueue priority source

查看每个节点正在运行的插件

GET _cat/plugins?v

name     component          version
data-2   x-pack-core        6.2.4
data-2   x-pack-deprecation 6.2.4
data-2   x-pack-graph       6.2.4
data-2   x-pack-logstash    6.2.4
data-2   x-pack-ml          6.2.4
data-2   x-pack-monitoring  6.2.4
data-2   x-pack-security    6.2.4
data-2   x-pack-upgrade     6.2.4
data-2   x-pack-watcher     6.2.4
client-1 x-pack-core        6.2.4
client-1 x-pack-deprecation 6.2.4
client-1 x-pack-graph       6.2.4
client-1 x-pack-logstash    6.2.4
client-1 x-pack-ml          6.2.4
client-1 x-pack-monitoring  6.2.4
client-1 x-pack-security    6.2.4
client-1 x-pack-upgrade     6.2.4
client-1 x-pack-watcher     6.2.4
master-1 x-pack-core        6.2.4
master-1 x-pack-deprecation 6.2.4
master-1 x-pack-graph       6.2.4
master-1 x-pack-logstash    6.2.4
master-1 x-pack-ml          6.2.4
master-1 x-pack-monitoring  6.2.4
master-1 x-pack-security    6.2.4
master-1 x-pack-upgrade     6.2.4
master-1 x-pack-watcher     6.2.4
data-1   x-pack-core        6.2.4
data-1   x-pack-deprecation 6.2.4
data-1   x-pack-graph       6.2.4
data-1   x-pack-logstash    6.2.4
data-1   x-pack-ml          6.2.4
data-1   x-pack-monitoring  6.2.4
data-1   x-pack-security    6.2.4
data-1   x-pack-upgrade     6.2.4
data-1   x-pack-watcher     6.2.4

查看每个节点的自定义属性

GET /_cat/nodeattrs?v

node     host  ip              attr              value
data-2   node3 192.168.113.103 ml.machine_memory 1028517888
data-2   node3 192.168.113.103 ml.max_open_jobs  20
data-2   node3 192.168.113.103 ml.enabled        true
client-1 node4 192.168.113.104 ml.machine_memory 1856888832
client-1 node4 192.168.113.104 ml.max_open_jobs  20
client-1 node4 192.168.113.104 ml.enabled        true
master-1 node1 192.168.113.101 ml.machine_memory 1028517888
master-1 node1 192.168.113.101 ml.max_open_jobs  20
master-1 node1 192.168.113.101 ml.enabled        true
data-1   node2 192.168.113.102 ml.machine_memory 1028517888
data-1   node2 192.168.113.102 ml.max_open_jobs  20
data-1   node2 192.168.113.102 ml.enabled        true

查看索引分片的恢复视图

##索引分片的恢复视图,包括正在进行和先前已完成的恢复
##只要索引分片移动到群集中的其他节点，就会发生恢复事件
GET _cat/recovery/.kibana?v&format=json&pretty

[
  {
    "index": ".kibana",
    "shard": "0",
    "time": "446ms",
    "type": "empty_store",
    "stage": "done",
    "source_host": "n/a",
    "source_node": "n/a",
    "target_host": "node2",
    "target_node": "data-1",
    "repository": "n/a",
    "snapshot": "n/a",
    "files": "0",
    "files_recovered": "0",
    "files_percent": "0.0%",
    "files_total": "0",
    "bytes": "0",
    "bytes_recovered": "0",
    "bytes_percent": "0.0%",
    "bytes_total": "0",
    "translog_ops": "0",
    "translog_ops_recovered": "0",
    "translog_ops_percent": "100.0%"
  },
  {
    "index": ".kibana",
    "shard": "0",
    "time": "2s",
    "type": "peer",
    "stage": "done",
    "source_host": "node2",
    "source_node": "data-1",
    "target_host": "node3",
    "target_node": "data-2",
    "repository": "n/a",
    "snapshot": "n/a",
    "files": "1",
    "files_recovered": "1",
    "files_percent": "100.0%",
    "files_total": "1",
    "bytes": "230",
    "bytes_recovered": "230",
    "bytes_percent": "100.0%",
    "bytes_total": "230",
    "translog_ops": "0",
    "translog_ops_recovered": "0",
    "translog_ops_percent": "100.0%"
  }
]

查看每个数据节点上fielddata当前占用的堆内存

全文检索用倒排索引非常合适;但过滤、分组聚合、排序这些操作，正排索引更合适。

ES中引入了fielddata的数据结构用来做正排索引。如果需要对某一个字段排序、分组聚合、过滤，则可将字段设置成fielddata。

默认情况下:

text类型的字段是不能分组及排序的，如需要则需要开启该字段的fielddata=true,但是这样耗费大量的内存，不建议这么使用。

keyword类型默认可分组及排序。

fielddata默认是采用懒加载的机制加载到堆内存中。当某个字段基数特别大，可能会出现OOM。

GET _cat/fielddata?v&h=node,field,size

node   field                      size
data-1 kibana_stats.kibana.uuid     0b
data-1 kibana_stats.kibana.status   0b
data-2 kibana_stats.kibana.uuid     0b
data-2 kibana_stats.kibana.status   0b

##对某一字段进行查看
GET _cat/fielddata?v&h=node,field,size&fields=kibana_stats.kibana.uuid

node   field                    size
data-2 kibana_stats.kibana.uuid   0b
data-1 kibana_stats.kibana.uuid   0b

查看注册的快照仓库

GET _cat/repositories?v

id type

查看快照仓库下的快照

##可将ES中的一个或多个索引定期备份到如HDFS、S3等更可靠的文件系统，以应对灾难性的故障
##第一次快照是一个完整拷贝，所有后续快照则保留的是已存快照和新数据之间的差异
##当出现灾难性故障时，可基于快照恢复

GET _cat/snapshots/repo1?v

查看每个节点线程池的统计信息

##查看每个节点bulk线程池的统计信息
## actinve（活跃的），queue（队列中的）和 reject（拒绝的）
GET _cat/thread_pool/bulk?v&format=json&pretty

[
  {
    "node_name": "data-2",
    "name": "bulk",
    "active": "0",
    "queue": "0",
    "rejected": "0"
  },
  {
    "node_name": "client-1",
    "name": "bulk",
    "active": "0",
    "queue": "0",
    "rejected": "0"
  },
  {
    "node_name": "master-1",
    "name": "bulk",
    "active": "0",
    "queue": "0",
    "rejected": "0"
  },
  {
    "node_name": "data-1",
    "name": "bulk",
    "active": "0",
    "queue": "0",
    "rejected": "0"
  }
]

查看索引

GET _cat/indices/.monitoring*?v&h=index,health

index                           health
.monitoring-es-6-2018.08.25     green
.monitoring-kibana-6-2018.08.25 green

查看别名

GET _cat/aliases?v&h=alias,index

alias     index
.security .security-6

查看索引模板

GET _cat/templates?v&format=json&pretty

[
  {
    "name": "logstash-index-template",
    "index_patterns": "[.logstash]",
    "order": "0",
    "version": null
  },
  {
    "name": "security_audit_log",
    "index_patterns": "[.security_audit_log*]",
    "order": "2147483647",
    "version": null
  },
  {
    "name": ".monitoring-kibana",
    "index_patterns": "[.monitoring-kibana-6-*]",
    "order": "0",
    "version": "6020099"
  },
  {
    "name": ".watches",
    "index_patterns": "[.watches*]",
    "order": "2147483647",
    "version": null
  },
  {
    "name": ".monitoring-beats",
    "index_patterns": "[.monitoring-beats-6-*]",
    "order": "0",
    "version": "6020099"
  },
  {
    "name": ".ml-notifications",
    "index_patterns": "[.ml-notifications]",
    "order": "0",
    "version": "6020499"
  },
  {
    "name": ".ml-anomalies-",
    "index_patterns": "[.ml-anomalies-*]",
    "order": "0",
    "version": "6020499"
  },
  {
    "name": ".ml-state",
    "index_patterns": "[.ml-state]",
    "order": "0",
    "version": "6020499"
  },
  {
    "name": "security-index-template",
    "index_patterns": "[.security-*]",
    "order": "1000",
    "version": null
  },
  {
    "name": ".watch-history-7",
    "index_patterns": "[.watcher-history-7*]",
    "order": "2147483647",
    "version": null
  },
  {
    "name": ".ml-meta",
    "index_patterns": "[.ml-meta]",
    "order": "0",
    "version": "6020499"
  },
  {
    "name": ".monitoring-alerts",
    "index_patterns": "[.monitoring-alerts-6]",
    "order": "0",
    "version": "6020099"
  },
  {
    "name": ".monitoring-logstash",
    "index_patterns": "[.monitoring-logstash-6-*]",
    "order": "0",
    "version": "6020099"
  },
  {
    "name": ".triggered_watches",
    "index_patterns": "[.triggered_watches*]",
    "order": "2147483647",
    "version": null
  },
  {
    "name": ".monitoring-es",
    "index_patterns": "[.monitoring-es-6-*]",
    "order": "0",
    "version": "6020099"
  },
  {
    "name": "kibana_index_template:.kibana",
    "index_patterns": "[.kibana]",
    "order": "0",
    "version": null
  }
]

查看单个或某类或整个集群文档数

##整个集群文档数
GET _cat/count?v
epoch      timestamp count
1535185950 16:32:30  3008

##某类索引文档数
GET _cat/count/.monitoring*?v
epoch      timestamp count
1535186185 16:36:25  2162

注意:只包含实际文档数，不包括尚未清除的已删除文档。

查看每个索引的分片

GET _cat/shards?v&format=json&pretty&s=index
[
  {
    "index": ".kibana",
    "shard": "0",
    "prirep": "p",
    "state": "STARTED",
    "docs": "1",
    "store": "4kb",
    "ip": "192.168.113.102",
    "node": "data-1"
  },
  {
    "index": ".kibana",
    "shard": "0",
    "prirep": "r",
    "state": "STARTED",
    "docs": "1",
    "store": "4kb",
    "ip": "192.168.113.103",
    "node": "data-2"
  },
  {
    "index": ".monitoring-es-6-2018.08.25",
    "shard": "0",
    "prirep": "p",
    "state": "STARTED",
    "docs": "2557",
    "store": "1.6mb",
    "ip": "192.168.113.102",
    "node": "data-1"
  },
  {
    "index": ".monitoring-es-6-2018.08.25",
    "shard": "0",
    "prirep": "r",
    "state": "STARTED",
    "docs": "2557",
    "store": "1.5mb",
    "ip": "192.168.113.103",
    "node": "data-2"
  },
  {
    "index": ".monitoring-kibana-6-2018.08.25",
    "shard": "0",
    "prirep": "p",
    "state": "STARTED",
    "docs": "211",
    "store": "110.1kb",
    "ip": "192.168.113.102",
    "node": "data-1"
  },
  {
    "index": ".monitoring-kibana-6-2018.08.25",
    "shard": "0",
    "prirep": "r",
    "state": "STARTED",
    "docs": "211",
    "store": "110.1kb",
    "ip": "192.168.113.103",
    "node": "data-2"
  },
  {
    "index": ".security-6",
    "shard": "0",
    "prirep": "p",
    "state": "STARTED",
    "docs": "3",
    "store": "9.8kb",
    "ip": "192.168.113.102",
    "node": "data-1"
  },
  {
    "index": ".security-6",
    "shard": "0",
    "prirep": "r",
    "state": "STARTED",
    "docs": "3",
    "store": "9.8kb",
    "ip": "192.168.113.103",
    "node": "data-2"
  }
]

查看每个索引的segment

GET _cat/segments/.kibana?v&format=json&pretty

[
  {
    "index": ".kibana",
    "shard": "0",
    "prirep": "p",
    "ip": "192.168.113.102",
    "segment": "_2",
    "generation": "2",
    "docs.count": "1",
    "docs.deleted": "0",
    "size": "3.7kb",
    "size.memory": "1346",
    "committed": "true",
    "searchable": "true",
    "version": "7.2.1",
    "compound": "true"
  },
  {
    "index": ".kibana",
    "shard": "0",
    "prirep": "r",
    "ip": "192.168.113.103",
    "segment": "_2",
    "generation": "2",
    "docs.count": "1",
    "docs.deleted": "0",
    "size": "3.7kb",
    "size.memory": "1346",
    "committed": "true",
    "searchable": "true",
    "version": "7.2.1",
    "compound": "true"
  }
]

参考文献

https://blog.csdn.net/wangpei1949/article/details/82287444