AeroNotix

xrandr --output LVDS1 --mode 1600x900 --output VGA1 --mode 1280x1024 --right-of LVDS1 --output HDMI1 --mode 1920x1080 --right-of VGA1
xrandr: Configure crtc 2 failed

AeroNotix

~ xrandr -q
Screen 0: minimum 8 x 8, current 3520 x 1080, maximum 32767 x 32767
LVDS1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 382mm x 214mm
   1600x900      60.06*+
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
VGA1 connected (normal left inverted right x axis y axis)
   1280x1024     75.02    75.02    60.02  
   1152x864      75.00  

AeroNotix

~ erl
Erlang R16B02 (erts-5.10.3) [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V5.10.3  (abort with ^G)
1> 'Łukasz'.
* 1: illegal atom

AeroNotix

    case OldSock of undefined -> ok ;
                    _ -> ok = gen_udp:close(OldSock)
    end,


%% "should be" (according to OTP rules)

    case OldSock of undefined -> ok ;
        _ -> ok = gen_udp:close(OldSock)
    end,

AeroNotix

  "Given a set of :add operations followed by a final :read, verifies that
  every successfully added element is present in the read, and that the read
  contains only elements for which an add was attempted."
  (reify Checker
    (check [this test model history]
      (let [attempts (->> history
                          (r/filter knossos/invoke?)
                          (r/filter #(= :add (:f %)))
                          (r/map :value)
                          (into #{}))

AeroNotix

(gen/phases
                                (->> (range sample-size)
                                  (map (fn [x] {:type  :invoke
                                                :f     :add
                                                :value x}))
                                  gen/seq
                                  (gen/stagger 1/10)
                                  (gen/delay 1)
                                  (gen/nemesis
                                    (gen/seq

AeroNotix

Notes about creating a Jepsen test

Implement jepsen.db.DB

• setup! [this test node]
  • The "provisioning" aspect of your test. Implement anything here which is needed to put the system under test into some state. For example, installing databases, bringing applications up

AeroNotix

def random_device(reuse_owner=False, **kwds):
    def wrapper(f):
        def wrapped(self):
            if reuse_owner and hasattr(self, 'device'):
                print "Reusing owner %s" % self.device
            else:
                print "no owner"
            return f(self)
        return wrapped
    return wrapper

AeroNotix

(defun trim-string (string)
  (replace-regexp-in-string
   "\\`[ \t\n]*" ""
   (replace-regexp-in-string "[ \t\n]*\\'" "" string)))

(defun move-to-export ()
  (search-backward "-export"))

(defun go-to-export-end ()
  (search-forward "])."))

AeroNotix

-spec
gather_child_data(pid(), string(), [binary()]) -> [binary()].
gather_child_data(Conn, Path, ChildPaths) ->
    [begin
         BinPath = list_to_binary(Path ++ "/"),
         NewPath =  binary_to_list(<<BinPath/binary, Child/binary>>),
         {ok, {NodeData, _}} = ezk:get(Conn, NewPath),
         NodeData
     end || Child <- ChildPaths].