Index Service and Auto Failover

Hi,

We have a 9 node cluster:
5 x data
2 x index/query
2 x search

Today we lost one index/query node because of a hardware failure. And from that point 50% of the queries returned a error?! I saw then “Auto-failover for index service is disabled.” in the log. Triggered manual failover, and everything was working again. Puh… And definitely my fault. It’s clearly documented, that index service is not automatically failed over unless a data service is running on the same host. I completely missed that, and seems I never lost a index node in years of couchbase use :slight_smile:

Now the question is… how should I setup my cluster, so I have multi dimensional scaling AND auto failover?

I think this would work for example:
6 x data/index
3 x query/search
That will failover index because there is also a data service. But I lose the split of data and index, which would be good for scaling and performance.

As I now know, my setup
5 x data
2 x index/query
2 x search
will not auto failover, because index can’t do that and there is no data service on the same host.

What about this:
5 x data
2 x index
2 x search/query
index will not failover, but maybe query service knows that one of the index nodes is not available and uses the other one. Will that work?

Thanks for any ideas how to setup this correctly.

Thanks, Pascal

@gizmo74,

You can setup equivalent indexes on the indexer nodes so that your scan’s are not impacted even incase of a failover of one of the nodes. Query would automatically pick the index on the other node in that case. Regarding your question, your understanding is correct and the below configuration would work

5 x data
2 x index
2 x search/query

Thanks,
Varun