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Elasticsearch

1. API

Elasticsearch 的 API 在官方文档上有很详细的介绍,我这里仅列举出平时用到的较多的 API,方便查询。

滚动升级集群

# 首先关闭 shard 的分配
PUT _cluster/settings
{
"persistent": {
"cluster.routing.allocation.enable": "none"
}
}
# 然后写入硬盘
POST _flush/synced
# 升级完成后打开
PUT _cluster/settings
{
"persistent": {
"cluster.routing.allocation.enable": null
}
}

Query API

# 时间范围查询
GET element-quantity-2/_search
{
"query": {
"range": {
"timestamp": {
"lte": "2018.11.13",
"format": "yyyy.MM.dd"
}
}
}
}
# 值的种类查询
GET element-quantity-2/_search
{
"size": 0,
"query": {
"match_all": {}
},
"aggs": {
"count": {
"cardinality": {
"field": "databag_id"
}
}
}
}

Cat API

# 通用参数
## 显示标题
?v
## 选择显示哪些列
?h=A,B,C
## 排序
?s=A:desc,B
# 获取素有的节点
GET _cat/nodes
# 获取所有的 index
GET _cat/indices?v
# 获取符合某个 pattern 的 index 的 shard
GET _cat/shards/${pattern}
# 获取所有的 shard,按照 state 排序
GET _cat/shards?v&s=state
# 获取所有的 shard,显示指定列
GET _cat/shards?h=index,shard,prirep,state,unassigned.reason
# 获取特定类型的 thread_pool
GET /_cat/thread_pool/bulk,flush,refresh?v&h=node_name,name,active,queue,rejected,completed
# 获取所有的 thread_pool
GET /_cat/thread_pool?v&h=node_name,name,active,queue,rejected,completed

Index API

# 关闭 Index
POST logstash-bfaccesslog-2018.12/_close
# 删除 Index,匹配格式
DELETE .monitoring-*
# 统一修改所有 index 的配置
PUT _settings
{
"index": {
"blocks": {
"read_only_allow_delete": "false"
}
}
}
# 修改某个 index 的配置
PUT portal/_settings
{
"index": {
"number_of_replicas":1
}
}
# 获取所有 index 的配置
GET _settings
# 获取所有 template
GET _template
# 增加自己的 template
PUT _template/my_logstash
{
"index_patterns": ["logstash-*"],
"order": 1,
"settings": {
"number_of_shards": 1
}
}
# 当 node 丢失的时候,shard 重新分配延迟时间
PUT _all/_settings
{
"settings": {
"index.unassigned.node_left.delayed_timeout": "5m"
}
}

Cluster API

# 获取所有关闭的 index
GET _cluster/state/blocks?pretty
# 获取集群的配置
GET /_cluster/settings
# 分析 Shard 分配问题
GET /_cluster/allocation/explain
# 获取各个节点上的 task
GET _tasks
# 获取所有数据节点和存储空间
GET _cat/allocation?v

Shard Allocation

  • cluster.routing.allocation.enable
    • all - (default) Allows shard allocation for all kinds of shards.
    • primaries - Allows shard allocation only for primary shards.
    • new_primaries - Allows shard allocation only for primary shards for new indices.
    • none - No shard allocations of any kind are allowed for any indices.
  • cluster.routing.rebalance.enable
    • all - (default) Allows shard balancing for all kinds of shards.
    • primaries - Allows shard balancing only for primary shards.
    • replicas - Allows shard balancing only for replica shards.
    • none - No shard balancing of any kind are allowed for any indices.
  • cluster.routing.allocation.allow_rebalance
    • always - Always allow rebalancing.
    • indices_primaries_active - Only when all primaries in the cluster are allocated.
    • indices_all_active - (default) Only when all shards (primaries and replicas) in the cluster are allocated.
  • cluster.routing.allocation.disk.threshold_enabled
    • true - default
    • false
  • index.unassigned.node_left.delayed_timeout
    • 见 Index API。
    • 注意:此配置是 index 级别的,所以就算配置的时候指定为_all新建的 index 也不会有这个配置。可以用 template 的方式增加此配置。

2. Tuning

  • index.refresh_interval:由 Buffer 写入 Segment(在 OS cache 中) 的频率,默认 1s。
  • index.merge.scheduler.max_thread_count:merge 操作的最大线程,默认有个公式,详情参考官方
  • index.translog.durability:默认 request,表示同步写入,参考官方文档
  • index.translog.sync_interval:默认 5s,表示 translog 由 OS cache 写入硬盘的频率。需要 close index 才能修改。
对于已存在的 index:
PUT .monitoring-*/_settings
{
"index": {
"refresh_interval": "30s",
"translog.durability": "async",
"merge.scheduler.max_thread_count": 1
}
}
对于以后创建的 index:
  • order:数值越大越后执行,会覆盖数值小的。
PUT _template/my_config
{
"index_patterns": ["*"],
"order" : 1,
"settings": {
"index": {
"refresh_interval": "30s",
"translog.durability": "async",
"translog.sync_interval": "100s",
"merge.scheduler.max_thread_count": 1
}
}
}
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On this page
1. API
滚动升级集群
Query API
Cat API
Index API
Cluster API
Shard Allocation
2. Tuning