Important: RHEL6 and other newer Linux distributions are known to have the Transparent Huge Pages (THP) feature enabled by default. THP can cause issues in database software, including Couchbase Server. THP can cause nodes to lose cluster heartbeats and auto-failover.
Disabling THP prior to installing Couchbase Server is strongly encouraged.
Tip: Modern NICs have multiple RX and TX queues to provide concurrent handling for network requests. By default, most Linux distributions configure CPU0 to handle all network interrupts for all the queues. For a system running with a high rate of TCP requests, this can become a bottleneck as CPU0 has to handle all the requests. To achieve better performance, network queue IRQs can be distributed to all the cores uniformly. A 2X improvement in the GSI scan throughput was observed by reconfiguring the interrupt CPU affinity.