Question

我需要通过Ansible在不同的区域创建一个只读副本。

docs似乎没有提及这是否可行。他们只提到正常的只读副本：

#input dimension
r <- 10
c <- 3

#input matrices
dt <- matrix(runif(r*c),r,c)
wt <- matrix(c(1,0,0,0,2,0,0,0,1),3,3) #weights

#column controller
c.limit <- c(60,50,70)

#create structure for lpSolve
ncol <- r*c
lp.create <- make.lp(ncol=ncol)
set.type(lp.create, columns=1:ncol, type = c("binary"))

#create objective values 
obj.vals <- as.vector(t(dt%*%wt))
set.objfn(lp.create, obj.vals) 
lp.control(lp.create,sense='max')

#Add constraints to ensure sum of parameters for every row (rowSum) <= 1
for (i in 1:r){
 add.constraint(lp.create, xt=c(1,1,1),
             indices=c(3*i-2,3*i-1,3*i), rhs=1, type="<=")
}

#Add constraints to ensure sum of parameters for every column (colSum) <= column limit (defined above)
for (i in 1:c){
 add.constraint(lp.create, xt=rep(1,r),
             indices=seq(i,ncol,by=c), rhs=c.limit[i], type="<=")
}

#Add constraints to ensure sum of column objective (t((dt%*%wt)[,i])%*%P[,i) <= limits defined in the problem)
#NOT SURE HOW TO APPLY A CONSTRAINT THAT IS DEPENDENT ON THE OBJECTIVE FUNCTION

solve(lp.create)
get.objective(lp.create) #20
final.par <- matrix(get.variables(lp.create), ncol = c, byrow=T) # Reshape

Answer 1

创建跨区域副本时，它与创建普通只读副本的工作方式完全相同，只是不必指定实例标识符，而是必须指定完整的ARN。这意味着如果您在帐户my-mysql-instance中的US East 1中有一个名为123456789012的源实例，那么您的ARN（以及RDS模块的instance_name参数）将如下所示：

arn:aws:rds:us-east-1:123456789012:db:my-mysql-instance

所以你只需要调整文档中的复制任务就可以了：

- rds:
    command: replicate
    region: eu-west-1
    instance_name: new-database-replica
    source_instance: arn:aws:rds:us-east-1:123456789012:db:my-mysql-instance
    wait: yes
    wait_timeout: 600

这将在位于US West 1的名为new-database-replica的源数据库实例中，在EU West 1（爱尔兰）中创建一个名为my-mysql-instance的新只读副本。

有没有办法创建RDS实例的跨区域只读副本？

1 个答案: