Physical machine

GCE n1-standard-2 machine type

  • 1x dedicated local SSD mounted under /var/lib/etcd
  • 1x dedicated slow disk for the OS
  • 7.5 GB memory
  • 2x CPUs

etcd

etcd Version: 2.2.0-rc.0+git
Git SHA: 103cb5c
Go Version: go1.5
Go OS/Arch: linux/amd64

Testing

Start 3-member etcd cluster, each of which uses 2 cores.

The length of key name is always 64 bytes, which is a reasonable length of average key bytes.

Memory Maximal Usage

  • etcd may use maximal memory if one follower is dead and the leader keeps sending snapshots.
  • max RSS is the maximal memory usage recorded in 3 runs.
value bytes key number data size(MB) max RSS(MB) max RSS/data rate on leader
128 50000 6 433 72x
128 100000 12 659 54x
128 200000 24 1466 61x
1024 50000 48 1253 26x
1024 100000 96 2344 24x
1024 200000 192 4361 22x

Data Size Threshold

  • When etcd reaches data size threshold, it may trigger leader election easily and drop part of proposals.
  • For most cases, the etcd cluster should work smoothly if it doesn't hit the threshold. If it doesn't work well due to insufficient resources, decrease its data size.
value bytes key number limitation suggested data size threshold(MB) consumed RSS(MB)
128 400K 48 2400
1024 300K 292 6500