We have a lot of performance issues with our couchbase server, most docs fail when we try to retrieve them from the nodejs client with a timeout. I think it is when we request a large number of inactive docs (on disk, not memory) that they fail. Our couchbase console has always reported <1% cache miss ratio though, so I always assumed memory usage was not the problem since it seems like 99% of our gets are being sent from memory. I ran the cbhealthcheck tool today and it has a lot of warnings about low memory and it says we should increase our memory:
Active resident ratio - Not enough RAM in the cluster. Active resident item ratio '11.64%' is below '30.00% Impact: Performing failover will slow down nodes severely because it will likely require information stored on disk Average item loaded time - Poor ep-engine key performance indicators Average item loaded time '69.241 ms' is slower than '500 us' Impact: Server performance is below expectation
The couchbase console says Active Resident Ratio is % of active items cached in RAM, so mu understanding is that this is saying only 12% of our active items are cached in RAM, but also that we have <1% cache miss ratio. How can those stats be that way? Am I misunderstanding what they are actually saying? We’re using Couchbase 3.1.0.