# Backend存储

Skywalking存储可插拔，我们提供了以下存储解决方案，你可以通过更改'application.yml`轻松使用。

原生支持的存储e

H2
ElasticSearch 6
MySQL
TiDB

支持存储的重分发版本。

ElasticSearch 5

# H2

要激活h2作为存储，设置存储提供者为内存中的 H2。默认的在发布的包中。请阅读[h2官方文件]（http://www.h2 database.com/html/features.html）中的Database URL Overview，您可以在Embedded, Server and Mixed 模式下将目标设置为H2。

设置片段示例

storage:
  h2:
    driver: org.h2.jdbcx.JdbcDataSource
    url: jdbc:h2:mem:skywalking-oap-db
    user: sa

# ElasticSearch 6

要激活ElasticSearch 6作为存储, 设置存储提供者为elasticsearch。

需要ElasticSearch 6.3.0或更高版本。HTTP RestHighLevelClient被用来连接服务器

设置片段示例

storage:
  elasticsearch:
    # nameSpace: ${SW_NAMESPACE:""}
    # user: ${SW_ES_USER:""} # User needs to be set when Http Basic authentication is enabled
    # password: ${SW_ES_PASSWORD:""} # Password to be set when Http Basic authentication is enabled
    clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:localhost:9200}
    indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:2}
    indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
    # Batch process setting, refer to https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-docs-bulk-processor.html
    bulkActions: ${SW_STORAGE_ES_BULK_ACTIONS:2000} # Execute the bulk every 2000 requests
    bulkSize: ${SW_STORAGE_ES_BULK_SIZE:20} # flush the bulk every 20mb
    flushInterval: ${SW_STORAGE_ES_FLUSH_INTERVAL:10} # flush the bulk every 10 seconds whatever the number of requests
    concurrentRequests: ${SW_STORAGE_ES_CONCURRENT_REQUESTS:2} # the number of concurrent requests

# ElasticSearch 6 与 Zipkin 的追踪扩展

这个实现共享了大部分的 elasticsearch，只是扩展到支持Zipkin-Span存储。它有所以相同的配置。

storage:
  zipkin-elasticsearch:
    nameSpace: ${SW_NAMESPACE:""}
    clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:localhost:9200}
    user: ${SW_ES_USER:""}
    password: ${SW_ES_PASSWORD:""}
    indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:2}
    indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
    # Batch process setting, refer to https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-docs-bulk-processor.html
    bulkActions: ${SW_STORAGE_ES_BULK_ACTIONS:2000} # Execute the bulk every 2000 requests
    bulkSize: ${SW_STORAGE_ES_BULK_SIZE:20} # flush the bulk every 20mb
    flushInterval: ${SW_STORAGE_ES_FLUSH_INTERVAL:10} # flush the bulk every 10 seconds whatever the number of requests
    concurrentRequests: ${SW_STORAGE_ES_CONCURRENT_REQUESTS:2} # the number of concurrent requests

# ElasticSearch 6 with Jaeger trace extension

这个实现共享了大部分的 elasticsearch，只是扩展到支持Jaeger -Span存储。它有所以相同的配置。

storage:
  jaeger-elasticsearch:
    nameSpace: ${SW_NAMESPACE:""}
    clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:localhost:9200}
    user: ${SW_ES_USER:""}
    password: ${SW_ES_PASSWORD:""}
    indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:2}
    indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
    # Batch process setting, refer to https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-docs-bulk-processor.html
    bulkActions: ${SW_STORAGE_ES_BULK_ACTIONS:2000} # Execute the bulk every 2000 requests
    bulkSize: ${SW_STORAGE_ES_BULK_SIZE:20} # flush the bulk every 20mb
    flushInterval: ${SW_STORAGE_ES_FLUSH_INTERVAL:10} # flush the bulk every 10 seconds whatever the number of requests
    concurrentRequests: ${SW_STORAGE_ES_CONCURRENT_REQUESTS:2} # the number of concurrent requests

# About Namespace

设置名称空间后，ElasticSearch中所有索引的名称都将使用它作为前缀。

# About Authentication

我们只支持basic authentication。如果需要，可以设置user and password.。有关如何启用HTTP基本身份验证，请阅读这个https://brudtkuhl.com/blog/securing-elasticsearch/。

# MySQL

要激活MySQL作为存储, 设置存储提供者为mysql。

注意: Apache官方发行版和源代码中不允许使用MySQL驱动程序。请自己下载MySQL驱动程序。将连接驱动程序jar复制到oap-libs。

storage:
  mysql:

所有与连接相关的设置，包括链接URL、用户名和密码都在datasource-settings.properties。设置文件参考HikariCP 连接池文档。.

# TiDB

目前的测试版tidb版本为2.0.9和MySQL客户端驱动版本为8.0.13。要激活TiDB作为存储,设置存储提供者为mysql。

storage:
  mysql:

所有与连接相关的设置，包括链接URL、用户名和密码都在datasource-settings.properties。所有配置都可参考上面的MySQL。

# ElasticSearch 5

ElasticSearch 5 和ElasticSearch 6的java客户端版本不兼容, 所有它不在原生发布中。. OpenSkywalking/SkyWalking-With-Es5x-Storage 包括这个发布版本。

# More storage solution extension

参考开发者指南Project Extensions document中的Storage extension development guide