The linux kernel contains queues where packets are stored after reception from a network interface controller before being processed by the next protocol stack. There is one netdev backlog queue per CPU core.
netdev_max_backlog defines the maximum number of packets that can enter the queue. Queues fill up when an interface receives packets faster than kernel can process them. The default
netdev_max_backlog value should be 1000. However this may not be enough in cases such as:
Multiple interfaces operating at 1Gbps, or even a single interface at 10Gbps.
Lower powered systems process very large amounts of network traffic.
Netdata agent monitors the average number of dropped packets in the last minute due to exceeding the netdev backlog queue.
Increase the netdev_max_backlog value
Check your current value:
root@netdata~ # sysctl net.core.netdev_max_backlog net.core.netdev_max_backlog = 1000
Try to increase it by a factor of 2.
root@netdata~ # sysctl -w net.core.netdev_max_backlog=2000
Verify the change and test with the same workload that triggered the alarm originally.
root@netdata~ # sysctl net.core.netdev_max_backlog net.core.netdev_max_backlog = 2000
If this change works for your system, you could make it permanently.
Reload the sysctl settings.
root@netdata~ # sysctl -p