machi/src/machi_chain_repair.erl

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%% -------------------------------------------------------------------
%%
%% Copyright (c) 2007-2015 Basho Technologies, Inc. All Rights Reserved.
%%
%% This file is provided to you under the Apache License,
%% Version 2.0 (the "License"); you may not use this file
%% except in compliance with the License. You may obtain
%% a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing,
%% software distributed under the License is distributed on an
%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
%% KIND, either express or implied. See the License for the
%% specific language governing permissions and limitations
%% under the License.
%%
%% -------------------------------------------------------------------
%% @doc Erlang API for the Machi FLU TCP protocol version 1, with a
%% proxy-process style API for hiding messy details such as TCP
%% connection/disconnection with the remote Machi server.
%%
%% Machi is intentionally avoiding using distributed Erlang for
%% Machi's communication. This design decision makes Erlang-side code
%% more difficult & complex, but it's the price to pay for some
%% language independence. Later in Machi's life cycle, we need to
%% (re-)implement some components in a non-Erlang/BEAM-based language.
%%
%% This module implements a "man in the middle" proxy between the
%% Erlang client and Machi server (which is on the "far side" of a TCP
%% connection to somewhere). This proxy process will always execute
%% on the same Erlang node as the Erlang client that uses it. The
%% proxy is intended to be a stable, long-lived process that survives
%% TCP communication problems with the remote server.
-module(machi_chain_repair).
-include("machi_projection.hrl").
-define(SHORT_TIMEOUT, 5*1000).
-define(LONG_TIMEOUT, 60*1000).
%% These macros assume there's a bound variable called Verb.
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-define(VERB(Fmt), if Verb -> io:format(Fmt ); true -> ok end).
-define(VERB(Fmt, Args), if Verb -> io:format(Fmt, Args); true -> ok end).
-export([repair_cp/4, repair_ap/6]).
repair_cp(Src, Dst, MembersDict, Opts) ->
%% TODO: add missing function: wipe away any trace of chunks
%% are present on Dst but missing on Src.
exit(todo_cp_mode).
repair_ap(Src, Repairing, UPI, MembersDict, ETS, Opts) ->
%% Use process dict so that 'after' clause can always quit all
%% proxy pids.
put(proxies_dict, orddict:new()),
Add = fun(Name, Pid) -> put(proxies_dict, orddict:store(Name, Pid, get(proxies_dict))) end,
OurFLUs = lists:usort([Src] ++ Repairing ++ UPI),
Res = try
[begin
{ok, Proxy} = machi_proxy_flu1_client:start_link(P),
Add(FLU, Proxy)
end || {FLU,P} <- MembersDict, lists:member(FLU, OurFLUs)],
ProxiesDict = get(proxies_dict),
D = dict:new(),
D2 = lists:foldl(fun({FLU, Proxy}, Dict) ->
append_file_dict(Proxy, FLU, Dict)
end, D, ProxiesDict),
MissingFileSummary = make_missing_file_summary(D2, OurFLUs),
io:format(user, "MissingFileSummary ~p\n", [MissingFileSummary]),
%% Repair files from perspective of Src, i.e. tail(UPI).
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RepairMode = proplists:get_value(repair_mode, Opts, repair),
[ok = repair_file(ap_mode, RepairMode, File, Size, MissingList,
proplists:get_value(verbose, Opts, true),
Src, ProxiesDict, ETS) ||
{File, {Size, MissingList}} <- MissingFileSummary],
ok
catch
What:Why ->
Stack = erlang:get_stacktrace(),
io:format(user, "What Why ~p ~p @\n\t~p\n",
[What, Why, Stack]),
{error, {What, Why, Stack}}
after
[(catch machi_proxy_flu1_client:quit(Pid)) ||
Pid <- orddict:to_list(get(proxies_dict))]
end,
Res.
make_missing_file_summary(Dict, AllFLUs) ->
%% FileFilterFun = fun(_) -> true end,
FoldRes = lists:sort(dict:to_list(Dict)),
%% NOTE: MissingFileSummary = [{File, {FileSize, ServersMissingFrom}}]
MissingFileSummary =
[begin
{GotIt, Sizes} = lists:unzip(GotSizes),
Size = lists:max(Sizes),
Missing = {File, {Size, AllFLUs -- GotIt}},
Missing
end || {File, GotSizes} <- FoldRes %% , FileFilterFun(File)
],
MissingFileSummary.
append_file_dict(Proxy, FLU_name, D) ->
{ok, Res} = machi_proxy_flu1_client:list_files(Proxy, ?DUMMY_PV1_EPOCH),
lists:foldl(fun({Size, File}, Dict) ->
dict:append(File, {FLU_name, Size}, Dict)
end, D, Res).
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%% TODO: There's no reason why repair can't be done 1).in parallel
%% across multiple repairees, and/or 2). with multiple byte ranges in
%% the same file, and/or 3). with bigger chunks.
%%
%% 1. Optimization
%% 2. Optimization
%% 3. Optimization, but it would be the easiest to implement, e.g. use
%% constant-sized 4MB chunks. Unfortuntely, it would also destroy
%% the ability to verify here that the chunk checksums are correct
%% *and* also propagate the correct checksum metadata to the
%% destination FLU.
%% As an additional optimization, add a bit of #2 to start the next
%% read while the current write is still in progress.
repair_file(ap_mode, RepairMode,
File, Size, [], Verb, Src, ProxiesDict, ETS) ->
?VERB("~p: ~s: present on both: ", [Src, File]),
?VERB("TODO!\n"), ok;
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%%TODO: repair_both_present(File, Size, RepairMode, V, SrcS, SrcS2, DstS, DstS2);
repair_file(ap_mode, RepairMode,
File, Size, MissingList, Verb, Src, ProxiesDict, ETS) ->
case lists:member(Src, MissingList) of
true ->
?VERB("~p: ~s -> ~p, skipping: not on source server\n",
[Src, File, MissingList]);
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false when RepairMode == check ->
?VERB("~p: ~s -> ~p, copy ~s MB (skipped)\n",
[Src, File, MissingList, mbytes(Size)]);
false ->
?VERB("~p: ~s -> ~p, copy ~s MB, ",
[Src, File, MissingList, mbytes(Size)]),
MissingProxiesDict =
orddict:filter(fun(K, _V) -> lists:member(K, MissingList) end,
ProxiesDict),
SrcProxy = orddict:fetch(Src, ProxiesDict),
ok = copy_file(File, SrcProxy, MissingProxiesDict, Verb, ETS),
?VERB("done\n", [])
end.
copy_file(File, SrcProxy, MissingProxiesDict, Verb, ETS) ->
%% Use the first source socket to enumerate the chunks & checksums.
%% Use the second source socket to copy each chunk.
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N = length(orddict:to_list(MissingProxiesDict)),
{ok, EpochID} = machi_proxy_flu1_client:get_epoch_id(SrcProxy,
?SHORT_TIMEOUT),
{ok, CheckSums} = machi_proxy_flu1_client:checksum_list(
SrcProxy, EpochID, File, ?LONG_TIMEOUT),
EtsKeys = [{in_files, t_in_files}, {in_chunks, t_in_chunks},
{in_bytes, t_in_bytes}, {out_files, t_out_files},
{out_chunks, t_out_chunks}, {out_bytes, t_out_bytes}],
[ets:insert(ETS, {L_K, 0}) || {L_K, _T_K} <- EtsKeys],
CopyChunks =
fun({Offset, Size, CSum}, {ok, ETS, _, _} = Acc) ->
case ets:lookup_element(ETS, in_chunks, 2) rem 100 of
0 -> ?VERB(".", []);
_ -> ok
end,
_T1 = os:timestamp(),
{ok, Chunk} = machi_proxy_flu1_client:read_chunk(
SrcProxy, EpochID, File, Offset, Size),
_T2 = os:timestamp(),
case machi_util:checksum_chunk(Chunk) of
CSum_now when CSum_now == CSum ->
[begin
_T3 = os:timestamp(),
ok = machi_proxy_flu1_client:write_chunk(
DstProxy, EpochID, File, Offset, Chunk),
_T4 = os:timestamp()
end || {_FLU, DstProxy} <- MissingProxiesDict],
ets:update_counter(ETS, in_chunks, 1),
ets:update_counter(ETS, in_bytes, Size),
ets:update_counter(ETS, out_chunks, N),
ets:update_counter(ETS, out_bytes, N*Size),
Acc;
CSum_now ->
error_logger:error_msg(
"TODO: Checksum failure: "
"file ~p offset ~p size ~p: "
"expected ~p got ~p\n",
[File, Offset, Size, CSum, CSum_now]),
ets:update_counter(ETS, t_bad_chunks, 1),
Acc
end;
(_, _=Acc) -> % failure: skip rest of file
Acc
end,
ets:update_counter(ETS, t_in_files, 1),
ets:update_counter(ETS, t_out_files, N),
_CopyRes = lists:foldl(CopyChunks, {ok, ETS, x, x}, CheckSums),
?VERB("copied ~w chunks to ~w chunks, ",
[ets:lookup_element(ETS, K, 2) || K <- [in_chunks, out_chunks] ]),
%% Copy this file's stats to the total counts.
[ets:update_counter(ETS, T_K, ets:lookup_element(ETS, L_K, 2)) ||
{L_K, T_K} <- EtsKeys],
ok.
%% copy_file_proc_checksum_fun(File, SrcS, DstS, _Verbose) ->
%% fun(<<OffsetHex:16/binary, " ", LenHex:8/binary, " ",
%% CSumHex:32/binary, "\n">>) ->
%% <<Len:32/big>> = hexstr_to_bin(LenHex),
%% DownloadChunkBin = <<OffsetHex/binary, " ", LenHex/binary, " ",
%% File/binary, "\n">>,
%% [Chunk] = escript_download_chunks(SrcS, {{{DownloadChunkBin}}},
%% fun(_) -> ok end),
%% CSum = hexstr_to_bin(CSumHex),
%% CSum2 = checksum(Chunk),
%% if Len == byte_size(Chunk), CSum == CSum2 ->
%% {_,_,_} = upload_chunk_write(DstS, OffsetHex, File, Chunk),
%% ok;
%% true ->
%% io:format("ERROR: ~s ~s ~s csum/size error\n",
%% [File, OffsetHex, LenHex]),
%% error
%% end;
%% (_Else) ->
%% ok
%% end.
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repair_both_present(File, Size, RepairMode, V, SrcS, _SrcS2, DstS, _DstS2) ->
verb("repair_both_present TODO\n"),
ok.
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%% io:format("repair_both_present: ~p ~p mode ~p\n", [File, Size, RepairMode]).
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%% repair_both_present(File, Size, RepairMode, V, SrcS, _SrcS2, DstS, _DstS2) ->
%% Tmp1 = lists:flatten(io_lib:format("/tmp/sort.1.~w.~w.~w", tuple_to_list(now()))),
%% Tmp2 = lists:flatten(io_lib:format("/tmp/sort.2.~w.~w.~w", tuple_to_list(now()))),
%% J_Both = lists:flatten(io_lib:format("/tmp/join.3-both.~w.~w.~w", tuple_to_list(now()))),
%% J_SrcOnly = lists:flatten(io_lib:format("/tmp/join.4-src-only.~w.~w.~w", tuple_to_list(now()))),
%% J_DstOnly = lists:flatten(io_lib:format("/tmp/join.5-dst-only.~w.~w.~w", tuple_to_list(now()))),
%% S_Identical = lists:flatten(io_lib:format("/tmp/join.6-sort-identical.~w.~w.~w", tuple_to_list(now()))),
%% {ok, FH1} = file:open(Tmp1, [write, raw, binary]),
%% {ok, FH2} = file:open(Tmp2, [write, raw, binary]),
%% try
%% K = md5_ctx,
%% MD5_it = fun(Bin) ->
%% {FH, MD5ctx1} = get(K),
%% file:write(FH, Bin),
%% MD5ctx2 = crypto:hash_update(MD5ctx1, Bin),
%% put(K, {FH, MD5ctx2})
%% end,
%% put(K, {FH1, crypto:hash_init(md5)}),
%% ok = escript_checksum_list(SrcS, File, fast, MD5_it),
%% {_, MD5_1} = get(K),
%% SrcMD5 = crypto:hash_final(MD5_1),
%% put(K, {FH2, crypto:hash_init(md5)}),
%% ok = escript_checksum_list(DstS, File, fast, MD5_it),
%% {_, MD5_2} = get(K),
%% DstMD5 = crypto:hash_final(MD5_2),
%% if SrcMD5 == DstMD5 ->
%% verb("identical\n", []);
%% true ->
%% ok = file:close(FH1),
%% ok = file:close(FH2),
%% _Q1 = os:cmd("./REPAIR-SORT-JOIN.sh " ++ Tmp1 ++ " " ++ Tmp2 ++ " " ++ J_Both ++ " " ++ J_SrcOnly ++ " " ++ J_DstOnly ++ " " ++ S_Identical),
%% case file:read_file_info(S_Identical) of
%% {ok, _} ->
%% verb("identical (secondary sort)\n", []);
%% {error, enoent} ->
%% io:format("differences found:"),
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%% repair_both(File, Size, V, RepairMode,
%% J_Both, J_SrcOnly, J_DstOnly,
%% SrcS, DstS)
%% end
%% end
%% after
%% catch file:close(FH1),
%% catch file:close(FH2),
%% [(catch file:delete(FF)) || FF <- [Tmp1,Tmp2,J_Both,J_SrcOnly,J_DstOnly,
%% S_Identical]]
%% end.
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%% repair_both(File, _Size, V, RepairMode, J_Both, J_SrcOnly, J_DstOnly, SrcS, DstS) ->
%% AccFun = if RepairMode == check ->
%% fun(_X, List) -> List end;
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%% RepairMode == repair ->
%% fun( X, List) -> [X|List] end
%% end,
%% BothFun = fun(<<_OffsetSrcHex:16/binary, " ",
%% LenSrcHex:8/binary, " ", CSumSrcHex:32/binary, " ",
%% LenDstHex:8/binary, " ", CSumDstHex:32/binary, "\n">> =Line,
%% {SameB, SameC, DiffB, DiffC, Ds}) ->
%% <<Len:32/big>> = hexstr_to_bin(LenSrcHex),
%% if LenSrcHex == LenDstHex,
%% CSumSrcHex == CSumDstHex ->
%% {SameB + Len, SameC + 1, DiffB, DiffC, Ds};
%% true ->
%% %% D = {OffsetSrcHex, LenSrcHex, ........
%% {SameB, SameC, DiffB + Len, DiffC + 1,
%% AccFun(Line, Ds)}
%% end;
%% (_Else, Acc) ->
%% Acc
%% end,
%% OnlyFun = fun(<<_OffsetSrcHex:16/binary, " ", LenSrcHex:8/binary, " ",
%% _CSumHex:32/binary, "\n">> = Line,
%% {DiffB, DiffC, Ds}) ->
%% <<Len:32/big>> = hexstr_to_bin(LenSrcHex),
%% {DiffB + Len, DiffC + 1, AccFun(Line, Ds)};
%% (_Else, Acc) ->
%% Acc
%% end,
%% {SameBx, SameCx, DiffBy, DiffCy, BothDiffs} =
%% file_folder(BothFun, {0,0,0,0,[]}, J_Both),
%% {DiffB_src, DiffC_src, Ds_src} = file_folder(OnlyFun, {0,0,[]}, J_SrcOnly),
%% {DiffB_dst, DiffC_dst, Ds_dst} = file_folder(OnlyFun, {0,0,[]}, J_DstOnly),
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%% if RepairMode == check orelse V == true ->
%% io:format("\n\t"),
%% io:format("BothR ~p, ", [{SameBx, SameCx, DiffBy, DiffCy}]),
%% io:format("SrcR ~p, ", [{DiffB_src, DiffC_src}]),
%% io:format("DstR ~p", [{DiffB_dst, DiffC_dst}]),
%% io:format("\n");
%% true -> ok
%% end,
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%% if RepairMode == repair ->
%% ok = repair_both_both(File, V, BothDiffs, SrcS, DstS),
%% ok = repair_copy_chunks(File, V, Ds_src, DiffB_src, DiffC_src,
%% SrcS, DstS),
%% ok = repair_copy_chunks(File, V, Ds_dst, DiffB_dst, DiffC_dst,
%% DstS, SrcS);
%% true ->
%% ok
%% end.
%% repair_both_both(_File, _V, [_|_], _SrcS, _DstS) ->
%% %% TODO: fetch both, check checksums, hopefully only exactly one
%% %% is correct, then use that one to repair the other. And if the
%% %% sizes are different, hrm, there may be an extra corner case(s)
%% %% hiding there.
%% io:format("WHOA! We have differing checksums or sizes here, TODO not implemented, but there's trouble in the little village on the river....\n"),
%% timer:sleep(3*1000),
%% ok;
%% repair_both_both(_File, _V, [], _SrcS, _DstS) ->
%% ok.
%% repair_copy_chunks(_File, _V, [], _DiffBytes, _DiffCount, _SrcS, _DstS) ->
%% ok;
%% repair_copy_chunks(File, V, ToBeCopied, DiffBytes, DiffCount, SrcS, DstS) ->
%% verb("\n", []),
%% verb("Starting copy of ~p chunks/~s MBytes to \n ~s: ",
%% [DiffCount, mbytes(DiffBytes), File]),
%% InnerCopyFun = copy_file_proc_checksum_fun(File, SrcS, DstS, V),
%% FoldFun = fun(Line, ok) ->
%% ok = InnerCopyFun(Line) % Strong sanity check
%% end,
%% ok = lists:foldl(FoldFun, ok, ToBeCopied),
%% verb(" done\n", []),
%% ok.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
file_folder(Fun, Acc, Path) ->
{ok, FH} = file:open(Path, [read, raw, binary]),
try
file_folder2(Fun, Acc, FH)
after
file:close(FH)
end.
file_folder2(Fun, Acc, FH) ->
file_folder2(file:read_line(FH), Fun, Acc, FH).
file_folder2({ok, Line}, Fun, Acc, FH) ->
Acc2 = Fun(Line, Acc),
file_folder2(Fun, Acc2, FH);
file_folder2(eof, _Fun, Acc, _FH) ->
Acc.
verb(Fmt) ->
verb(Fmt, []).
verb(Fmt, Args) ->
case {ok, true} of % application:get_env(kernel, verbose) of
{ok, true} -> io:format(Fmt, Args);
_ -> ok
end.
mbytes(0) ->
"0.0";
mbytes(Size) ->
lists:flatten(io_lib:format("~.1.0f", [max(0.1, Size / (1024*1024))])).