Docker PerformancePresented By

Ali Hussain, CTO Flux7

Benchmarking

Comparison of

○ Native

○ Docker

○ KVM (full virtualization)

Work in progress

Run Sysbench

Elapsed time between KVM and Docker within 1%

Noticeable difference in CPU usage○ 3% for KVM ○ 1.5% for Docker

Memory Usage○ KVM reserves the memory upfront.

Microbenchmarks

Get a better understanding of details

Not representative of a real workload○ Exaggerates Specific Behavior

Tool 1: Coremark - CPU Performance

CPU Performance - Coremark

Run native, Docker, and KVM

○ Performance difference within std dev (<3%)

CPU Performance - Coremark

Tool 2: FIO - IO Performance

FIO - First Pass

FIO - First Pass

Docker performance 7x faster than native

○ Perfect run everything on Docker :)

FIO - First Pass

What Gives?

Hypothesis: Docker saving to RAM

Let’s try with host-mounted volumes

FIO - Docker host mounted

Collectd - Memory Usage

Collectd - Memory Usage

Collectd - Disk bandwidth

Docker FIO Conclusion

Aufs is stripping flush flags○ Diving deeper into why

But is this bad?

Tool 3: iPerf

Docker within 10%

Next Steps

Try on MAC VLAN

Run on KVM

Questions