facebook市值多少:Facebook 用户量十分庞大,为什么还使用 MySQL 数据库?作者:fleuria

发布时间:2020-06-03 06:00:22   来源:网络 关键词:facebook市值多少

facebook 在 TAO 的论文里有讲一点这方面的选型。既然是自己轮了一套存储层,理论上底层存储可以灵活选择,比如底层存 RocksDB 架构上会不会更清晰直接?论文里提了仍选择 mysql 的几点考虑与设计权衡:


4.1 Storage Layer

Objects and associations were stored in MySQL at Facebook
even before TAO was built; it was the backing store
for the original PHP implementation of the API. This
made it the natural choice for TAO’s persistent storage.

The TAO API is mapped to a small set of simple
SQL queries, but it could also be mapped efficiently to
range scans in a non-SQL data storage system such as
LevelDB [3] by explicitly maintaining the required indexes.
When evaluating the suitability of a backing store
for TAO, however, it is important to consider the data
accesses that don’t use the API. These include backups,
bulk import and deletion of data, bulk migrations
from one data format to another, replica creation, asynchronous
replication, consistency monitoring tools, and
operational debugging. An alternate store would also
have to provide atomic write transactions, efficient granular
writes, and few latency outliers.

Given that TAO needs to handle a far larger volume of
data than can be stored on a single MySQL server, we
divide data into logical shards. Each shard is contained
in a logical database. Database servers are responsible
for one or more shards. In practice, the number of shards
far exceeds the number of servers; we tune the shard to
server mapping to balance load across different hosts. By
default all object types are stored in one table, and all
association types in another.

-- usenix.org/system/files

更多回复:

知乎网友知乎用户:
观念在改变.
对数据库的功能要求在一直的减少.
数据库内置的各种高级特性正在被各种各样的应用服务器取代.数据库服务器越来越纯粹,就是安全的保存数据.
甚至就连数据缓存,现在的趋势也是越来越重视应用服务器端的缓存.而不是把更多的精力放在数据库缓存那.
至于原因?很简单,服务支持再好的数据库,其进化周期也远远的大于应用服务的进化.

知乎网友知乎用户:
观念在改变.
对数据库的功能要求在一直的减少.
数据库内置的各种高级特性正在被各种各样的应用服务器取代.数据库服务器越来越纯粹,就是安全的保存数据.
甚至就连数据缓存,现在的趋势也是越来越重视应用服务器端的缓存.而不是把更多的精力放在数据库缓存那.
至于原因?很简单,服务支持再好的数据库,其进化周期也远远的大于应用服务的进化.






本文关键词:facebook市值多少
猜你喜欢
推荐文章: