Running Drupal 7 on Linode NodeBalancer servers

We switched from a regular hosting plan to a high availability mutli-server configuration. Now we are faced with a number of Mission Critical issues that need to be resolved.

Running multi-master replication syncing both cache seams to be and issue.

Is anybody have a solution for this?

Running multi-master replication syncing both Solr seams to be and issue.

We moved Solr outside replication but now have to figure out how schedule jobs to re-index, run cron and clear cache on multiple sites on Linux CentOS 7 OS.

If anybody is Running Drupal 7 on Linode NodeBalancer servers and is willing to share best practices we would greatly appreciate it.