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72 commits

Author SHA1 Message Date
Scott Lystig Fritchie
96ca7b7082 Bugfix for rare race between just-finished repair and flapping ending
Fix for today: We are going to game the system.  We know that
    C100 is going to be checking authorship relative to P_current's
    UPI's tail.  Therefore, we're just going to set it here.
    Why???  Because we have been using this projection safely for
    the entire flapping period!  ... The only other way I see is to
    allow C100 to carve out an exception if the repair finished
    PLUS author_server check fails PLUS if we came from here, but
    that feels a bit fragile to me: if some code factoring happens
    in projection_transition_is_saneprojection_transition_is_sane()
    or elsewhere that causes the author_server check to be
    something-other-than-the-final-thing-checked, then such a
    refactoring would likely cause an even harder bug to find &
    fix.  Conditions tested: 5 FLUs plus alternating partitions of:
    [
     [{a,b}], [], [{a,b}], [], [{a,b}], [], [{a,b}], [], [{a,b}], [],
     [{b,a},{d,e}],
     [{a,b}], [], [{a,b}], [], [{a,b}], [], [{a,b}], [], [{a,b}], []
    ].
2015-07-07 01:29:37 +09:00
Scott Lystig Fritchie
54b5014446 WIP: bugfix in transition, just-in-case commit 2015-07-06 23:56:29 +09:00
Scott Lystig Fritchie
9d4b4b1df6 Bugfix: update inner projection based on *previous inner* projection 2015-07-06 17:38:15 +09:00
Scott Lystig Fritchie
3f8982cbe1 MAJOR WIP: set author's rank to constant 0? Worthwhile?? 2015-07-06 16:12:15 +09:00
Scott Lystig Fritchie
471cde1f2c WIP: debugging fmt shuffle 2015-07-06 16:11:14 +09:00
Scott Lystig Fritchie
8ee3377fa7 Fix a state transition bug (chain manager infinite loop, oops)
%% We have a small problem for state transition sanity checking in the
    %% case where we are flapping *and* a repair has finished.  One of the
    %% sanity checks in simple_chain_state_transition_is_sane(() is that
    %% the author of P2 in this case must be the tail of P1's UPI: i.e.,
    %% it's the tail's responsibility to perform repair, therefore the tail
    %% must damn well be the author of any transition that says a repair
    %% finished successfully.
    %%
    %% The problem is that author_server of the inner projection does not
    %% reflect the actual author!  See the comment with the text
    %% "The inner projection will have a fake author" in
    %react_to_env_A30().
    %%
    %% So, there's a special return value that tells us to try to check for
    %% the correct authorship here.
2015-07-05 14:52:50 +09:00
Scott Lystig Fritchie
920c0fc610 WIP: much better structure for inner projection sanity checking 2015-07-04 16:46:02 +09:00
Scott Lystig Fritchie
8241d1f600 WIP: cruft, needs refactoring 2015-07-04 14:57:38 +09:00
Scott Lystig Fritchie
65ee0c23ec Adjust author of inner projections to yield same checksum 2015-07-04 01:58:00 +09:00
Scott Lystig Fritchie
cd026303a0 Unused var cleanup 2015-07-04 00:35:05 +09:00
Scott Lystig Fritchie
9b0a5a1dc3 WIP: 1st part of moving old chain state transtion code to new
Ha, famous last words, amirite?

    %% The chain sequence/order checks at the bottom of this function aren't
    %% as easy-to-read as they ought to be.  However, I'm moderately confident
    %% that it isn't buggy.  TODO: refactor them for clarity.

So, now machi_chain_manager1:projection_transition_is_sane() is using
newer, far less buggy code to make sanity decisions.

TODO: Add support for Retrospective mode. TODO is it really needed?

Examples of how the old code sucks and the new code sucks less.

    138> eqc:quickcheck(eqc:testing_time(10, machi_chain_manager1_test:prop_compare_legacy_with_v2_chain_transition_check(whole))).
    xxxxxxxxxxxx..x.xxxxxx..x.x....x..xx........................................................Failed! After 69 tests.
    [a,b,c]
    {c,[a,b,c],[c,b],b,[b,a],[b,a,c]}
    Old_res ([335,192,166,160,153,139]): true
    New_res: false (why line [1936])
    Shrinking xxxxxxxxxxxx.xxxxxxx.xxx.xxxxxxxxxxxxxxxxx(3 times)
    [a,b,c]
 %% {Author1,UPI1,   Repair1,Author2,UPI2, Repair2} %%
    {c,      [a,b,c],[],     a,      [b,a],[]}
    Old_res ([338,185,160,153,147]): true
    New_res: false (why line [1936])
    false

Old code is wrong: we've swapped order of a & b, which is bad.

    139> eqc:quickcheck(eqc:testing_time(10, machi_chain_manager1_test:prop_compare_legacy_with_v2_chain_transition_check(whole))).
    xxxxxxxxxx..x...xx..........xxx..x..............x......x............................................(x10)...(x1)........Failed! After 120 tests.
    [b,c,a]
    {c,[c,a],[c],a,[a,b],[b,a]}
    Old_res ([335,192,185,160,153,123]): true
    New_res: false (why line [1936])
    Shrinking xx.xxxxxx.x.xxxxxxxx.xxxxxxxxxxx(4 times)
    [b,a,c]
 %% {Author1,UPI1,Repair1,Author2,UPI2, Repair2} %%
    {a,      [c], [],     c,      [c,b],[]}
    Old_res ([338,185,160,153,147]): true
    New_res: false (why line [1936])
    false

Old code is wrong: b wasn't repairing in the previous state.

    150> eqc:quickcheck(eqc:testing_time(10, machi_chain_manager1_test:prop_compare_legacy_with_v2_chain_transition_check(whole))).
    xxxxxxxxxxx....x...xxxxx..xx.....x.......xxx..x.......xxx...................x................x......(x10).....(x1)........xFailed! After 130 tests.
    [c,a,b]
    {b,[c],[b,a,c],c,[c,a,b],[b]}
    Old_res ([335,214,185,160,153,147]): true
    New_res: false (why line [1936])
    Shrinking xxxx.x.xxx.xxxxxxx.xxxxxxxxx(4 times)
    [c,b,a]
 %% {Author1,UPI1,Repair1,Author2,UPI2,   Repair2} %%
    {c,      [c], [a,b],  c,      [c,b,a],[]}
    Old_res ([335,328,185,160,153,111]): true
    New_res: false (why line [1981,1679])
    false

Old code is wrong: a & b were repairing but UPI2 has a & b in the wrong order.
2015-07-04 00:32:28 +09:00
Scott Lystig Fritchie
42fb6dd002 WIP: it's clear that the legacy state transition check is broken, II 2015-07-03 23:37:36 +09:00
Scott Lystig Fritchie
caeb322725 WIP: it's clear that the legacy state transition check is broken 2015-07-03 23:17:34 +09:00
Scott Lystig Fritchie
83015c319d WIP: yeah, now we're going places 2015-07-03 22:05:35 +09:00
Scott Lystig Fritchie
6a706cbfeb WIP: Refactoring and prototyping goop, broken test 2015-07-03 19:21:41 +09:00
Scott Lystig Fritchie
a658a64482 Cosmetic formatting change 2015-07-01 15:37:53 +09:00
Scott Lystig Fritchie
22337e1819 Remove short circuit (bad idea!) from react_to_env_C100() 2015-06-15 17:22:02 +09:00
Scott Lystig Fritchie
b244a3b8e4 Reduce verbosity, try fix up convergence demo for chain len=4 2015-06-15 12:41:16 +09:00
Scott Lystig Fritchie
9bf76e0bfb Fix for correctness bug, thanks PULSE 2015-06-05 01:06:39 +09:00
Scott Lystig Fritchie
be62300b3b Bug fixes: model and real bugs, thanks PULSE and converge_demo both! 2015-06-04 17:39:29 +09:00
Scott Lystig Fritchie
0cf9627f26 Bugfix, found by inspection, yay! 2015-06-04 15:05:37 +09:00
Scott Lystig Fritchie
89b8b6a012 Bugfix, found by PULSE, yay! 2015-06-04 14:31:58 +09:00
Scott Lystig Fritchie
d3df2bd31d WIP: remove repair_always_done option, it was flawed 2015-06-03 15:26:22 +09:00
Scott Lystig Fritchie
87417d2872 WIP: get the old jalopy into runnable shape 2015-06-03 11:48:55 +09:00
Scott Lystig Fritchie
2207151eba Fix projection_transition_is_sane() bug 2015-06-02 21:20:50 +09:00
Scott Lystig Fritchie
deabe14d29 Un-proplist-ify the inner projection 2015-06-02 20:55:18 +09:00
Scott Lystig Fritchie
207be8729b Un-proplist-ify the flapping_i info 2015-06-02 20:32:52 +09:00
Scott Lystig Fritchie
000d687588 Fix creation_time bug in inner projection 2015-06-02 16:26:49 +09:00
Scott Lystig Fritchie
69244691f4 Such wonder when one *reads* the docs... 2015-05-20 14:12:48 +09:00
Scott Lystig Fritchie
a4266e8aa4 Fix known chain repair bugs, add basic smoke test 2015-05-19 19:32:48 +09:00
Scott Lystig Fritchie
a347722a15 Fix {error,not_written} type bugs in chmgr 2015-05-18 17:32:22 +09:00
Scott Lystig Fritchie
d293170e92 WIP: starting machi_cr_client.erl 2015-05-17 23:48:05 +09:00
Scott Lystig Fritchie
10364834de Add a dummy client-side implementation module:machi_yessir_client.erl 2015-05-17 19:00:51 +09:00
Scott Lystig Fritchie
5c2635346f Basic multi-party chain repair for ap_mode finished 2015-05-16 17:39:58 +09:00
Scott Lystig Fritchie
a9c753ad64 WIP: more generic all-way file chunk merge func 2015-05-15 17:15:02 +09:00
Scott Lystig Fritchie
eec029b08f WIP: aside, fix FLU wedge status @ init() 2015-05-13 17:59:32 +09:00
Scott Lystig Fritchie
4ae0f94649 WIP: move to stats via ETS, success/failure propagates, yay! 2015-05-12 23:45:35 +09:00
Scott Lystig Fritchie
cad84442bb WIP: stats record, hrm 2015-05-12 22:42:03 +09:00
Scott Lystig Fritchie
8807f954ff WIP: Whole file repair is 95% complete, yay! 2015-05-12 21:45:40 +09:00
Scott Lystig Fritchie
f48720e4dc WIP: set up proxies for repair 2015-05-12 12:56:41 +09:00
Scott Lystig Fritchie
1c70a46b09 Add basic process & bookkeeping structure for repair proc
=INFO REPORT==== 11-May-2015::19:50:09 ===
    Chain tail a of [a] starting repair of [c]

    =INFO REPORT==== 11-May-2015::19:50:12 ===
    Chain tail a of [a]: repair finished in 2.438 seconds: todo_yo
2015-05-11 19:50:21 +09:00
Scott Lystig Fritchie
c82000dc30 Reduce spamminess slightly 2015-05-11 19:00:21 +09:00
Scott Lystig Fritchie
33bfbe109e Chain manager bug fixes & enhancment (more...)
* Set max length of a chain at -define(MAX_CHAIN_LENGTH, 64).

* Perturb tick sleep time of each manager

* If a chain manager L has zero members in its chain, and then its local
public projection store (authored by some remote author R) has a projection
that contains L, then adopt R's projection and start humming consensus.

* Handle "cross-talk" across projection stores, when chain membership
is changed administratively, e.g. chain was [a,b,c] then changed to merely
[a], but that change only happens on a.  Servers b & c continue to use
stale projections and scribble their projection suggestions to a, causing
it to flap.

What's really cool about the flapping handling is that it *works*.  I
wasn't thinking about this scenario when designing the flapping logic, but
it's really nifty that this extra scenario causes a to flap and then a's
inner projection remains stable, yay!

* Add complaints when "cross-talk" is observed.

* Fix flapping sleep time throttle.

* Fix bug in the machi_projection_store.erl's bookkeeping of the
max epoch number when flapping.
2015-05-11 18:41:45 +09:00
Scott Lystig Fritchie
7906e6c235 WIP: basic wedge notifications now working 2015-05-08 18:17:41 +09:00
Scott Lystig Fritchie
762aef557f WIP: Set the stage for FLU wedging API 2015-05-08 15:36:53 +09:00
Scott Lystig Fritchie
ae1d038abe Change default value of chmgr's use_partition_simulator to false 2015-05-08 13:40:44 +09:00
Scott Lystig Fritchie
238c8472cd WIP: timeout comments 2015-05-07 18:52:01 +09:00
Scott Lystig Fritchie
14fc37bd0d Add ability to start FLUs at application startup 2015-05-07 18:39:39 +09:00
Scott Lystig Fritchie
517941aaaa Finish chain manager restart & membership changing 2015-05-07 17:52:16 +09:00
Scott Lystig Fritchie
aeb2e4ef9e WIP: partial refactoring of chmgr 2nd start code, one test broken 2015-05-06 11:41:04 +09:00