Application design recommendation

Hi everyone ,
I dont know this the right place to ask but here is my question.
In my use case we want to deploy 3 application in each datacenter. Also each datacenter has own elasticsearch cluster. Here is the tricky part for us. Data availablity is highly important for us.
We want to replicate data for 3 datacenter. And if one cluster down. On this datacenter’s application must keep writing. How can we design our applications and elasticsearch clusters.(We think we can use load balancer or proxy for applicaiton level. And bi-directional ccrl for elasticsearch but dont know how and this would help or can be done ?)

Best Regards.