Change sqlite database to mysq

Hi @xeroc, We would like to know if there is a way to change the bitshares.sqlite to other database link mysql. We are planning to load balance our application, and we would like for all of our instances(servers) to have the same bitshares key storage. We would like to know if there are any other ways to load balance our application without having an issue with the bitshares.sqlite?

首先确定 bitshares.sqlite 是如何打开的，以及 BitShares 密钥是如何存储的；该 issue 未指定源文件、测试或入口点。确定是否支持共享的 MySQL 后端存储或其他负载均衡方案，并将“提供一个有文档记录且经过测试的、用于在多个实例之间共享密钥存储的解决方案”定义为完成标准。

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