garage/script/jepsen.garage/README.md

jepsen.garage

Jepsen checking of Garage consistency properties.

Usage

Requirements:

• vagrant
• VirtualBox, configured so that nodes can take an IP in a private network 192.168.56.0/24
• a user that can create VirtualBox VMs
• leiningen
• gnuplot

Set up VMs:

vagrant up

Run tests (this one should fail):

lein run test --nodes-file nodes.vagrant --time-limit 64 --concurrency 50 --rate 50 --workload reg

These ones are working:

lein run test --nodes-file nodes.vagrant --time-limit 64 --rate 50  --concurrency 50 --workload set1
lein run test --nodes-file nodes.vagrant --time-limit 64 --rate 50  --concurrency 50 --workload set2

Results

Register linear, without timestamp patch

Command: lein run test --nodes-file nodes.vagrant --time-limit 60 --rate 20 --concurrency 20 --workload reg --ops-per-key 100

Results: fails with a simple clock-scramble nemesis.

Explanation: without the timestamp patch, nodes will create objects using their local clock only as a timestamp, so the ordering will be all over the place if clocks are scrambled.

Register linear, with timestamp patch

Command: lein run test --nodes-file nodes.vagrant --time-limit 60 --rate 20 --concurrency 20 --workload reg --ops-per-key 100 -I

Results:

• No failure with clock-scramble nemesis
• Fails with clock-scramble nemesis + partition nemesis

Explanation: S3 objects are not meant to behave like linearizable registers. TODO explain using a counter-example

Read-after-write CRDT register model: TODO: determine the expected semantics of such a register, code a checker and show that results are correct

Set, basic test

Command: lein run test --nodes-file nodes.vagrant --time-limit 60 --rate 20 --concurrency 20 --workload set1 --ops-per-key 100

Results:

• ListObjects returns objects not within prefix????

License

Copyright © 2023 Alex Auvolat

This program and the accompanying materials are made available under the terms of the GNU Affero General Public License v3.0.