Feature that greatly improves performance of EC2 NWing
- Required for high performance features like EC2 cluster placement groups
- ❗ Available for no charge, enabled by default on most modern EC2 instance types
- 💡 Tricky to see if it's enabled → check AWS docs for implementing it operationally
🔧 Uses SR-IOV → NW Interface Card (NIC) is virtualization aware
- Without SR-IOV: several instances talk to the same physical NIC of the EC2 host
- Host sits in the middle & controls which instance has access to the NIC
- NIC access control takes place in SW
- 👎 slows down NWing processes a lot
- 👎 consumes a lot of host CPU
- 💡 inefficient → can cause performance degradation when load is heavy
- With SR-IOV: NIC offers logical cards (multiple logical cards per physical NIC)
- Each instance is given exclusive access to a logical card
- NIC handles process E2E with instance without consuming a lot of host CPU
Benefits
- 👍 Higher I/O & lower host CPU usage
- More BW (more NWing speed, better scaling, host CPU not affected)
- Higher pps (packets-per-second)
- 💡 great for apps which rely on high NWing performance (e.g. those that shift lots of small packets across a small, isolated NW)
- 👍 Lower latency, but more importantly CONSISTENT lower latency