Q:DotNetCore.CAP.Processor (6.0升级到7.0)
EROR DotNetCore.CAP.Processor.MessageDelayedProcessor Schedule delayed message failed! System.NotSupportedException: Standalone servers do not support transactions.
EROR DotNetCore.CAP.Processor.MessageDelayedProcessor计划延迟消息失败！System.NotSupportedException：独立服务器不支持事务。
mongodb集群1
https://www.cnblogs.com/savorboard/p/mongodb-4-cluster-install.html
mongodb集群2
https://doc.rg1008.com/docs/rg_dev/rg_dev-1epdfh138n7cg
A:解决
https://github.com/dotnetcore/CAP/issues/812
This is by design, MongoDB needs to be deployed as a cluster, because MongoDB’s ACID transaction requires a cluster to be used.
根据设计，MongoDB需要作为集群部署，因为MongoDB的ACID事务需要使用集群。
see: https://cap.dotnetcore.xyz/user-guide/en/storage/mongodb/#mongodb
A:解决
https://github.com/dotnetcore/CAP/issues/1313
Only MongoDB 4.0+ cluster support transaction, We need to use transactions to guarantee the mutex for multiple instance concurrency get data.
只有MongoDB 4.0+集群支持事务，我们需要使用事务来保证多实例并发获取数据的互斥。
Q:mongodb 内存溢出
https://github.com/dotnetcore/CAP/issues/1379
