【es】索引状态为yellow,unassigned

1.集群状态为yellow 

curl -u elastic:elastic -k https://192.168.1.806:9200/_cluster/health
{"cluster_name":"es-cluster","status":"yellow","timed_out":false,"number_of_nodes":6,"number_of_data_nodes":3,
"active_primary_shards":417,"active_shards":839,"relocating_shards":0,"initializing_shards":0,
"unassigned_shards":2,"delayed_unassigned_shards":0,"number_of_pending_tasks":0,"number_of_in_flight_fetch":0,
"task_max_waiting_in_queue_millis":0,"active_shards_percent_as_number":99.76218787158146}

curl -XGET 'localhost:9200/_cat/indices?v&h=index,status'
yellow open   log_search_index lBeXQQh6TQaMrL5f4Vqodg   2   3      13716 0     37.5mb 10mb

某个索引状态为 yellow; 查看原因 

curl -u elastic:elastic  -k https://192.168.1.806:9200/_cluster/allocation/explain
{
    "note":"No shard was specified in the explain API request, so this response explains a randomly chosen unassigned shard. There may be other unassigned shards in this cluster which cannot be assigned for different reasons. It may not be possible to assign this shard until one of the other shards is assigned correctly. To explain the allocation of other shards (whether assigned or unassigned) you must specify the target shard in the request to this API.",
    "index":"log_search_index",
    "shard":1,
    "primary":false,
    "current_state":"unassigned",
    "unassigned_info":{
        "reason":"INDEX_CREATED",
        "at":"2025-05-29T08:00:04.800Z",
        "last_allocation_status":"no_attempt"
    },
    "can_allocate":"no",
    "allocate_explanation":"cannot allocate because allocation is not permitted to any of the nodes",
    "node_allocation_decisions":[
        {
            "node_id":"xo4a8Fe-TAGWocKin-gStw",
            "node_name":"master_03",
            "transport_address":"192.168.1.808:9300",
            "node_attributes":{
                "ml.machine_memory":"66918821888",
                "ml.max_open_jobs":"512",
                "xpack.installed":"true",
                "ml.max_jvm_size":"17179869184",
                "transform.node":"true"
            },
            "node_decision":"no",
            "weight_ranking":1,
            "deciders":[
                {
                    "decider":"same_shard",
                    "decision":"NO",
                    "explanation":"a copy of this shard is already allocated to this node [[log_search_index][1], node[xo4a8Fe-TAGWocKin-gStw], [R], s[STARTED], a[id=Og3qbC9nS1mLZCoxGpryRQ]]"
                }
            ]
        },
        {
            "node_id":"LLspvxI2S5CN99PVQdZm1Q",
            "node_name":"master_01",
            "transport_address":"192.168.1.806:9300",
            "node_attributes":{
                "ml.machine_memory":"66918821888",
                "ml.max_open_jobs":"512",
                "xpack.installed":"true",
                "ml.max_jvm_size":"17179869184",
                "transform.node":"true"
            },
            "node_decision":"no",
            "weight_ranking":2,
            "deciders":[
                {
                    "decider":"same_shard",
                    "decision":"NO",
                    "explanation":"a copy of this shard is already allocated to this node [[log_search_index][1], node[LLspvxI2S5CN99PVQdZm1Q], [P], s[STARTED], a[id=c1vIg3d2TQS_ot_Mz-MbXA]]"
                }
            ]
        },
        {
            "node_id":"VCf46L9LTV-iP5L1lJGypg",
            "node_name":"master_02",
            "transport_address":"192.168.1.807:9300",
            "node_attributes":{
                "ml.machine_memory":"66918821888",
                "ml.max_open_jobs":"512",
                "xpack.installed":"true",
                "ml.max_jvm_size":"17179869184",
                "transform.node":"true"
            },
            "node_decision":"no",
            "weight_ranking":3,
            "deciders":[
                {
                    "decider":"same_shard",
                    "decision":"NO",
                    "explanation":"a copy of this shard is already allocated to this node [[log_search_index][1], node[VCf46L9LTV-iP5L1lJGypg], [R], s[STARTED], a[id=A51JMuRkQ0iaPxCJLqfHEQ]]"
                }
            ]
        }
    ]
}

GET /user/_settings

某个索引状态为 yellow; 
curl -u elastic:elastic  -k https://192.168.1.806:9200/log_search_index/_settings

{
    "log_search_index":{
        "settings":{
            "index":{
                "routing":{
                    "allocation":{
                        "include":{
                            "_tier_preference":"data_content"
                        }
                    }
                },
                "number_of_shards":"2",
                "provided_name":"log_search_index",
                "creation_date":"1748505604797",
                "number_of_replicas":"3",
                "uuid":"lBeXQQh6TQaMrL5f4Vqodg",
                "version":{
                    "created":"7170099"
                }
            }
        }
    }
}

#设置副本数只有3个节点，副本数最大应该为2，这里副本数为3，所以有一个副本有问题。
#修改副本数为2;
curl -u elastic:elastic  -k -XPUT  https://192.168.1.806:9200/log_search_index/_settings  -H 'Content-Type: application/json' -d '
{

      "number_of_replicas" : 2
}'

[root@localhost ~]# sh es_status.sh 
epoch      timestamp cluster    status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1748511769 09:42:49  es-cluster green           6         3    839 417    0    0        0             0                  -                100.0%

由此可见，设置的副本数超过节点数，就会报yellow