C#程序错连SQL Server镜像库问题
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了C#程序错连SQL Server镜像库问题,小编现在分享给大家,供广大互联网技能从业者学习和参考。文章包含1985字,纯文字阅读大概需要3分钟。
内容图文
![C#程序错连SQL Server镜像库问题](/upload/InfoBanner/zyjiaocheng/1178/743456c693da45349716d3485b43ee1f.jpg)
SQL Server主库无异常日志,镜像库日志记录如下:
Login failed for user ‘XXX‘. Reason: Could not find a login matching the name provided.[CLIENT:XXX.XXX.XXX.XXX]
Error:18456, Serverity:14, State:5.
Login failed for user ‘XXX‘. Reason: Failed to open the explicitly specified database.[CLIENT:XXX.XXX.XXX.XXX]
Error:18456, Serverity:14, State:38.
以下是出现该问题的web程序配置,
配置1:
web服务器:.net framework4.5
web.config:timeout=300s,Min Pool Size=10,无";Failover Partner=PartnerServerName".
配置2:
web服务器:.net framework4.7
web.config:timeout=20s,Min Pool Size=10,无";Failover Partner=PartnerServerName".
微软的解释如下:
This issue occurs because of an error in the connection-retry algorithm for mirrored databases.
When the retry-algorithm is used, the data provider waits for the first read (SniReadSync) call to finish. The call is sent to the back-end computer that is running SQL Server, and the waiting time is calculated by multiplying the connection time-out value by 0.08. However, the data provider incorrectly sets a connection to a doomed state if a response is slow and if the first SniReadSync call is not completed before the waiting time expires.
Note The slow response in this case may be triggered either by the server or by network latency.
链接:https://support.microsoft.com/en-us/help/2605597/fix-time-out-error-when-a-mirrored-database-connection-is-created-by-t
出现此问题的原因是镜像数据库的连接重试算法中存在错误,程序第一次连接的等待时间为timeout*0.08,如果响应慢并且在等待时间内未完成,则进行重连,如下:
链接:https://docs.microsoft.com/zh-cn/sql/database-engine/database-mirroring/connect-clients-to-a-database-mirroring-session-sql-server
解决方案:
1) .NET Framework升级到4.5.2及以上
2)Timeout增大(预期值除以0.08),设置Min Pool Size
已确认通过该方法可以解决这个问题(已应用到生产环境)
如果耐心看完所有资料的,可能会发现微软的资料上说明配置了镜像的sqlserver需要在应用程序连接串中显式指定Failover Partner,即";Failover Partner=PartnerServerName". 为什么应用程序会在没有显式指定镜像库也会出现重连?
请看《Clarification on the Failover Partner in the connectionstring in Database Mirror setup》这篇文章。
原文:http://blog.51cto.com/aimax/2092045
内容总结
以上是互联网集市为您收集整理的C#程序错连SQL Server镜像库问题全部内容,希望文章能够帮你解决C#程序错连SQL Server镜像库问题所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错,欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 gblab@vip.qq.com 举报,一经查实,本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。