/Nats.Net.V2.ConcurrencyTests

Primary LanguageC#

JetStream Publish Tests

Run on 4-core Linux AMD64

Setup

In a separate terminal, start nats-server and leave it running

nats-server --js

No Latency

dotnet run -c Release --project Memory.Test
dotnet run -c Release --project Memory.Test.Legacy

Results:

V2 Avg: 0.090, Min: 0.026, Max: 0.208, Threads: 12
V1 Avg: 0.066, Min: 0.045, Max: 0.122, Threads: 8

Analysis: V1 is using sync I/O while V2 is using async I/O. With no latency over localhost, sync I/O is very fast and is not a bottleneck.

1ms Latency on interface (2ms round-trip)

Note: I had to add <ThreadPoolMinThreads>20</ThreadPoolMinThreads> to Memory.Test.Legacy.csproj to get past sync-over-async deadlocks

./scripts/add-latency.sh 1
dotnet run -c Release --project Memory.Test

# I had to set ThreadPoolMinThreads for Memory.Test.Legacy to to get past sync-over-async deadlocks
dotnet run -c Release --project Memory.Test.Legacy -p ThreadPoolMinThreads=20

Results:

V2 Avg: 0.101, Min: 0.035, Max: 0.170, Threads: 10
V1 Avg: 0.395, Min: 0.066, Max: 0.564, Threads: 30

Analysis: Sync-over-async calls in V1 block thread pool threads leading to increased contention in thread pool. Meanwhile V2's async/io allows for it to maintain efficient concurrency.

10ms Latency on interface (20ms round-trip)

./scripts/add-latency.sh 10
dotnet run -c Release --project Memory.Test
dotnet run -c Release --project Memory.Test.Legacy

Results:

V2 Avg: 0.199, Min: 0.124, Max: 0.345, Max Threads: 14
V1 Avg: 2.676, Min: 1.215, Max: 3.132, Max Threads: 33

Analysis: V1 thread pool is highly contentious now.

Limited thread pool with 1ms Latency on interface (2ms round-trip)

./scripts/add-latency.sh 1
dotnet run -c Release --project Memory.Test -p ThreadPoolMaxThreads=1
dotnet run -c Release --project Memory.Test.Legacy -p ThreadPoolMaxThreads=1

Results:

V2 Avg: 0.088, Min: 0.056, Max: 0.164, Max Threads: 4
V1: hangs

Analysis: V1 completely hangs because it hits a sync-over-async deadlock. V2 does just fine although it looks like the runtime didn't completely respect our request for 1 thread.

Cleanup

Remove latency

./scripts/rm-latency.sh