unassigned shareds 问题

Elasticsearch 版本为 5.5.0,下面是主要的核心流程,忽略异常补偿部分

问题来源

测试环境 ES 集群只有两台机器,昨晚不小心重启了一台,但是不知道为什么第二台机器突然崩了,原因还在排查,估计是数据量过大,一台机器难以承受,死机了.

GET /_cat/health

查看集群健康状态,发现完了,变成 RED 了,说明部分的分片可用，表明部分主分片损坏

1501728250 10:44:10 elasticsearch red 4 4 22 20 0 0 12 0
​

GET /_cat/shards

发现存在好多 UNASSIGNED 的分片

.marvel-2017.08.02     0 r STARTED     53054  97.5mb 123.57.68.250 123.57.68.250
.marvel-2017.08.02     0 p STARTED     53054  96.9mb 123.57.68.250 123.57.68.250
.marvel-2017.08.03     0 p STARTED     14729  34.9mb 10.251.1.123  123.56.125.43
.marvel-2017.08.03     0 r STARTED     14729  35.6mb 123.57.68.250 123.57.68.250
user_d                 0 p STARTED       938 904.2kb 10.251.1.123  123.56.125.43
user_d                 3 p UNASSIGNED
user_d                 1 p STARTED      1086   872kb 10.251.1.123  123.56.125.43
user_d                 2 p UNASSIGNED
index_v2               0 p STARTED    109226  23.5mb 10.251.1.123  123.56.125.43
index_v2               3 p STARTED    108133  23.3mb 10.251.1.123  123.56.125.43
index_v2               1 p STARTED    109711  23.6mb 123.57.68.250 123.57.68.250
index_v2               2 p STARTED    106542  22.9mb 123.57.68.250 123.57.68.250
contest                0 p STARTED        16  37.8kb 10.251.1.123  123.56.125.43
contest                3 p UNASSIGNED
contest                1 p STARTED        38 126.5kb 123.57.68.250 123.57.68.250
contest                2 p STARTED        50 113.8kb 10.251.1.123  123.56.125.43
.marvel-2017.01.10     0 p UNASSIGNED
.marvel-2017.01.10     0 r UNASSIGNED
contest_d              0 p UNASSIGNED
contest_d              3 p UNASSIGNED
contest_d              1 p STARTED        43  72.3kb 123.57.68.250 123.57.68.250
contest_d              2 p STARTED        44  79.5kb 123.57.68.250 123.57.68.250
user                   0 p STARTED    124228   120mb 123.57.68.250 123.57.68.250
user                   3 p STARTED    126029 120.9mb 123.57.68.250 123.57.68.250
user                   1 p UNASSIGNED
user                   2 p UNASSIGNED
index_d                0 p UNASSIGNED
index_d                3 p UNASSIGNED
index_d                1 p STARTED      3603   4.7mb 10.251.1.123  123.56.125.43
index_d                2 p STARTED      3586   4.3mb 10.251.1.123  123.56.125.43
500px.tribe-2017-03-27 0 p STARTED         5  69.9kb 123.57.68.250 123.57.68.250
500px.tribe-2017-03-27 3 p UNASSIGNED
500px.tribe-2017-03-27 1 p STARTED        10  63.8kb 10.251.1.123  123.56.125.43
500px.tribe-2017-03-27 2 p STARTED         4  52.3kb 10.251.1.123  123.56.125.43

​

curl -s "http://localhost:9200/_cat/shards" | grep UNASSIGNED

找出所有的 UNASSIGNED 的分片

index_d                0 p UNASSIGNED
index_d                3 p UNASSIGNED
contest                3 p UNASSIGNED
500px.tribe-2017-03-27 3 p UNASSIGNED
contest_d              0 p UNASSIGNED
contest_d              3 p UNASSIGNED
user_d                 3 p UNASSIGNED
user_d                 2 p UNASSIGNED
user                   1 p UNASSIGNED
user                   2 p UNASSIGNED
.marvel-2017.01.10     0 p UNASSIGNED
.marvel-2017.01.10     0 r UNASSIGNED
​

curl 'localhost:9200/_nodes/process?pretty'

查询得到 master 节点的唯一标识

"cluster_name": "elasticsearch",
 "nodes": { 
 "RVBi3XH_Qd2Mq1KAg5ELxg": 
 { "name": "123.57.68.250",
 "transport_address": "inet[/10.171.100.171:9300]",
 "host": "visualchina-dev-01", "ip": "123.57.68.250", 
 "version": "1.5.1",
 "build": "5e38401", 
 "http_address": "inet[/10.171.100.171:9200]",
 "attributes": { 
   "master": "true" 
 },
 "process": { 
  "refresh_interval_in_millis": 1000,
  "id": 26432,
  "max_file_descriptors": 65535,
  "mlockall": false }
  }
​

/_cluster/reroute

对 UNASSIGNED 分片进行重新分配

POST /_cluster/reroute
{
 "commands": [ 
 { 
 "allocate": {
 "index": "user_d", 
 "shard": 3,
 "node": "RVBi3XH_Qd2Mq1KAg5ELxg",
 "allow_primary": true 
 } 
 }
 ]
 }
​