I’m seeing signs for cluster being undersized in terms of CPU resources. We generally recommend 4 CPU cores for a basic Couchbase Server node
+1 additional core for each design document,
+1 additional core per each XDCR relationship.
If you want to speed up rebalance with current hardware, you could try one of the following options and see if it helps:
- Disable index aware rebalance, or
- Purge the view indexes for now and let rebalance complete. Once rebalance is done you can add view indexes back.
In long term, you should add more CPU firepower to your nodes.
Can’t say a lot based on error message you posted, though I would recommend to make sure your resident ratio is above 15% and your disk IO capacity is sufficient.