cannot be run because the QueueReader subsystem failed to load

前阵子一数据库服务器的事务日志开始暴增，当时使用下面脚本检查发现该数据库的log_reuse_wait_desc 一直处于replication状态， 也就是说在事务复制过程中，与发布相关的事务仍未传递到分发数据库。刚好前一天有个同事配置了aws的dms相关作业。

 

select name,  log_reuse_wait_desc from sys.databases;

 

找到具体作业检查发现，该作业的第二步出现了错误，logreader服务启动失败了。如需截图所示：

 

message

unable to start execution of step 2 (reason: the logreader subsystem failed to load [see the sqlagent.out file for details]; the job has been suspended).  the step failed.

 

 

进一步检查sql server agent的日志输出，发现是因为“because the queuereader subsystem failed to load”

 

 

 

 

 

date       2018/11/15 14:54:41

log        sql server agent (archive #1 - 2018/11/20 9:11:00)

message

[log] step 2 of job 'xxxx' (0xe00dff76d02dad47920124dd907a412d) cannot be run because the logreader subsystem failed to load.  the job has been suspended

date       2018/11/15 14:54:44

log        sql server agent (archive #1 - 2018/11/20 9:11:00)

message

[log] step 2 of job 'xxxx' (0x1bc045267cae2f4a8c3e283921f40641) cannot be run because the queuereader subsystem failed to load.  the job has been suspended

 

 

使用下面脚本检查，发现子系统queuereader的dll是存在的，刚好同事前一天配置aws时，在sql server里面添加了replication相关组件。而添加组件后，没有重启sql server agent服务。重启sql server agent服务后，问题解决！

 

 

select * from msdb.dbo.syssubsystems

 

 

 

参考资料：

 

https://www.sqlservercentral.com/forums/783200/replication-subsystems-failed-to-load