Problem
I got a project that will require to run two zabbix servers at once, looking into different hosts and objects. Well, I can simply say on the configuration to use different database names on the MySQL, although, wanting to use Elasticsearch as a history storage, it will not allow me to do the same. I cannot give custom names to the indices that zabbix will use. Installing two elasticsearch clusters is not an option as the one cluster is licensed.

Solution
As I need to go forward with the project, I have wrote a patch for Zabbix which allow me to work with prefixes to indices, allowing me to add a 5 character word in front of the index name..., but obviously, the best would be to have that implemented in Zabbix itself, so I don't have to patch my source in coming versions.

I see other similar requests but, I could not find one specifically to add this feature.

Attached you will find a patch that fix the problem on the server binary and the PHP interface and I have successfully deployed a server using such feature.

For the configuration file part, I just need to add this:

HistoryIndicePrefix=prefix

With this, it will allow me to run as many servers I want against the same elasticsearch cluster.