https://www.elastic.co/blog/elastic-stack-7-0-0-released


Kibana 7.0: new design & navigation … and dark mode!

全局导航
弹性UI框架
样式表简化 

增强的一致性和样式表的改进  暗黑模式 

A new era for cluster coordination in Elasticsearch

scale   resilient  弹性 
scalable reliable
cluster coordination layer   Zen Discovery
可伸缩性和可靠性

Zen2 is a completely new cluster coordination layer
Zen2 全新的协调层
faster, safer, and easier to use

there are well-known consensus algorithms, like Paxos, Raft, Zab and Viewstamped Replication (VR)
著名的一致性算法

the demands of an Elasticsearch cluster require higher throughput for cluster changes, 
support for easily growing or shrinking a cluster, 
and a seamless rolling upgrade strategy to allow 6.7 clusters to do a rolling upgrade to 7.0, 
features that these reference algorithms couldn’t provide.
 
高吞吐量集群变更 ， 集群 扩容 缩容 无缝滚动升级

Zen2 also includes a number of changes that reduce the likelihood of human error 
and provides clearer choices when recovering from catastrophic failure. 

Zen2还包括一些减少人为错误可能性的更改，并在从灾难性失败中恢复时提供更清晰的选择。

It’s not easy to improve reliability, performance and user experience all at once, especially in such a central component. 
同时提高可靠性、性能和用户体验并不容易，尤其是在这样一个核心组件中。

more about Zen2
https://www.elastic.co/blog/a-new-era-for-cluster-coordination-in-elasticsearch

 
Individual nodes in Elasticsearch are built with resiliency in mind. 
If you send too many requests to a node or your requests are too large, the node will push back.
如果向一个节点发送了太多的请求，或者您的请求太大，该节点将回推。

断路器  circuit breakers 

For nodes with smaller JVM heap sizes, 
which are becoming more common as users move to a cluster-per-tenant model 
rather than a massive multitenant cluster, this is even more important.

每个租户集群模型
大型多租户集群
把大集群拆分成小集群 

In 7.0, we’re introducing the real memory circuit breaker, 
which much more accurately detects unserviceable requests, 
and prevents them from making an individual node unstable.

7.0中引入了真正的内存断路器，更准确地检测不可用的请求，并防止它们使单个节点不稳定。


Giving relevance and speed a boost across use cases

相关性 和 速度 

Faster top k queries
In many search use cases, quickly seeing the top k (say 20) results on a query matters much more to the user than the exact hit count 
快速查看查询的top k(比如20)结果要比准确的点击率(例如，点击次数)重要得多

S7.0(Lucene 8.0)实现了一种新的算法(Block-Max WAND)
 

Intervals queries
legal and patent search, introduce the need to find records in which words or phrases are within a certain distance from each other.
法律和专利搜索  记录和词 短语的 距离匹配
Intervals queries in Elasticsearch 7.0 introduce a brand new way of structuring such queries, 
and are significantly simpler to use and define compared to the previous method (span queries). 
Intervals queries are also much more resilient to edge cases compared to span queries.

更容易使用和定义
边缘用例的适用性更强



Function score 2.0

Custom scoring   relevancy and results ranking
自定义打分   相关性 结果排序

7.0 introduces the next generation of function score capability 
that provides a simpler, modular, and more flexible way to generate a ranking score per record. 
The new modular structure allows users to mix 
and match a set of arithmetic and distance functions to construct arbitrary function score calculations, 
giving them more control over how results are scored and ranked.

7.0引入了下一代函数评分功能，它提供了一种更简单、模块化和更灵活的方法来生成每条记录的排名分数。
新的模块结构允许混合和匹配一组算术和距离函数来构造任意的函数得分计算，对结果的得分和排名有更多的控制。


Smooth zoom in Elastic Maps with geotile grid
平滑缩放  地图网格
tile 瓷砖

Lucene Bkd-Tree数据结构改善geoshape查询性能

introducing a new aggregation in Elasticsearch to handle (geo) map tiles in a way 
that allows a user to zoom in and out on the map without any change to the shape of the result data. 
引入了一个新的聚合来处理(geo)地图块，允许用户在不更改结果数据形状的情况下放大和缩小地图。

The new geotile_grid aggregation groups geo_points into buckets that represent cells in a grid, 
with each cell correlating with a tile in a map. 

新的geotile_grid聚合将geo_points分组到表示网格中单元格的桶中，每个单元格与映射中的一个tile相关联。

Prior to this change, the fringes of the shape could slightly change with the change in zoom level, 
because the rectangular tiles would change orientation at different zoom levels. 

在此之前，形状的边缘可能会随着缩放级别的变化而发生轻微的变化，因为矩形块会在不同的缩放级别上改变方向。

Elastic Maps in 7.0 is already using this new aggregation to ensure that your view stays stable as you zoom in and out. 

7.0中的Elastic Maps已经使用这种新的聚合来确保视图在缩放时保持稳定。




Strengthening time series use cases with nanosecond precision support
时间序列 纳秒精度

Whether it’s infrastructure metrics, system audit logs, network traffic, or a rover on Mars, 
time series data is central to how many people use the Elastic Stack. 
The ability to precisely order and correlate events across multiple systems and services is key.

基础设施指标、系统审计日志、网络流量，还是火星探测器
跨多个系统和服务精确排序和关联事件的能力


Up until now, Elasticsearch only stored timestamps with millisecond precision. 
7.0 adds a few zeroes and brings nanosecond precision, 
which allows users with high-frequency data collection needs the precision 
required to accurately store and sequence this data. 
The change was made possible by migrating from the historical JODA library to the official Java time API in JDK 8.