Re: Potential G2-item cycles under serializable isolation

On Wed, Jun 3, 2020 at 1:08 PM Peter Geoghegan <pg@bowt.ie> wrote:
> I can almost get this to work now. Thank you for accommodating me here.

Actually, I think that this was a simple error on my part. The
Jepsen/Elle test recipe that Kyle provided now works locally for me.
The tests actually pass, too -- at least against Postgres 13.

I don't know why Kyle doesn't see the same result. I acknowledge that
there is likely a bug here that I have yet to reproduce. My guess is
that it has something to do with the configuration -- though I need to
test earlier Postgres versions, too (Postgres 12 is what Kyle worked
against). I'm using a tuned postgresql.conf, whereas Kyle probably
didn't change many of the defaults.

Here is what I got just now:

pg@bat:~/code/jepsen/stolon$ lein run test-all -w append
--max-writes-per-key 4 --concurrency 50 -r 500 --isolation
serializable --time-limit 60 --nemesis none --existing-postgres --node
localhost --no-ssh --postgres-user jepsen --postgres-password pw

*** SNIP ***

INFO [2020-06-03 14:09:47,978] jepsen worker 33 - jepsen.stolon.append
:insert [#:next.jdbc{:update-count 1}]
INFO [2020-06-03 14:09:47,979] jepsen worker 33 - jepsen.util 133 :ok
:txn [[:r 8408 nil] [:append 8369 1] [:r 8402 [1 2 3]]]
INFO [2020-06-03 14:09:47,980] jepsen worker 15 - jepsen.util 115
:invoke :txn [[:append 8412 3]]
INFO [2020-06-03 14:09:47,981] jepsen worker 15 - jepsen.stolon.append
:update #:next.jdbc{:update-count 1}
INFO [2020-06-03 14:09:47,981] jepsen worker 15 - jepsen.util 115 :ok
:txn [[:append 8412 3]]
INFO [2020-06-03 14:09:48,012] jepsen test runner - jepsen.core Run
complete, writing
INFO [2020-06-03 14:09:48,912] jepsen test runner - jepsen.core Analyzing...
INFO [2020-06-03 14:09:51,415] jepsen test runner - jepsen.core
Analysis complete
INFO [2020-06-03 14:09:51,439] jepsen results - jepsen.store Wrote
/home/pg/code/jepsen/stolon/store/stolon append S (S)
/20200603T140847.000-0700/results.edn
INFO [2020-06-03 14:09:52,245] jepsen test runner - jepsen.core {:perf
 {:latency-graph {:valid? true},
  :rate-graph {:valid? true},
  :valid? true},
 :clock {:valid? true},
 :stats
 {:valid? true,
  :count 30096,
  :ok-count 27050,
  :fail-count 2992,
  :info-count 54,
  :by-f
  {:txn
   {:valid? true,
    :count 30096,
    :ok-count 27050,
    :fail-count 2992,
    :info-count 54}}},
 :exceptions {:valid? true},
 :workload {:valid? true},
 :valid? true}


Everything looks good! ヽ(‘ー`)ノ



# Successful tests

store/stolon append S (S) /20200603T140847.000-0700

1 successes
0 unknown
0 crashed
0 failures

--
Peter Geoghegan