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Diffstat (limited to 'src/couchdb/couch_replication_manager.erl')
| -rw-r--r-- | src/couchdb/couch_replication_manager.erl | 387 |
1 files changed, 0 insertions, 387 deletions
diff --git a/src/couchdb/couch_replication_manager.erl b/src/couchdb/couch_replication_manager.erl deleted file mode 100644 index 6537c8b2..00000000 --- a/src/couchdb/couch_replication_manager.erl +++ /dev/null @@ -1,387 +0,0 @@ -% Licensed 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. - --module(couch_replication_manager). --behaviour(gen_server). - --export([start_link/0, init/1, handle_call/3, handle_info/2, handle_cast/2]). --export([code_change/3, terminate/2]). - --include("couch_db.hrl"). - --define(DOC_ID_TO_REP_ID, rep_doc_id_to_rep_id). --define(REP_ID_TO_DOC_ID, rep_id_to_rep_doc_id). --define(INITIAL_WAIT, 5). - --record(state, { - changes_feed_loop = nil, - db_notifier = nil, - rep_db_name = nil, - rep_start_pids = [], - max_retries -}). - --import(couch_util, [ - get_value/2, - get_value/3 -]). - - -start_link() -> - gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). - -init(_) -> - process_flag(trap_exit, true), - _ = ets:new(?DOC_ID_TO_REP_ID, [named_table, set, protected]), - _ = ets:new(?REP_ID_TO_DOC_ID, [named_table, set, private]), - Server = self(), - ok = couch_config:register( - fun("replicator", "db", NewName) -> - ok = gen_server:cast(Server, {rep_db_changed, ?l2b(NewName)}); - ("replicator", "max_replication_retry_count", NewMaxRetries1) -> - NewMaxRetries = list_to_integer(NewMaxRetries1), - ok = gen_server:cast(Server, {set_max_retries, NewMaxRetries}) - end - ), - {Loop, RepDbName} = changes_feed_loop(), - {ok, #state{ - changes_feed_loop = Loop, - rep_db_name = RepDbName, - db_notifier = db_update_notifier(), - max_retries = list_to_integer( - couch_config:get("replicator", "max_replication_retry_count", "10")) - }}. - - -handle_call({rep_db_update, Change}, _From, State) -> - {reply, ok, process_update(State, Change)}; - -handle_call({triggered, {BaseId, _}}, _From, State) -> - [{BaseId, {DocId, true}}] = ets:lookup(?REP_ID_TO_DOC_ID, BaseId), - true = ets:insert(?REP_ID_TO_DOC_ID, {BaseId, {DocId, false}}), - {reply, ok, State}; - -handle_call({restart_failure, {Props} = RepDoc, Error}, _From, State) -> - DocId = get_value(<<"_id">>, Props), - [{DocId, {{BaseId, _} = RepId, MaxRetries}}] = ets:lookup( - ?DOC_ID_TO_REP_ID, DocId), - ?LOG_ERROR("Failed to start replication `~s` after ~p attempts using " - "the document `~s`. Last error reason was: ~p", - [pp_rep_id(RepId), MaxRetries, DocId, Error]), - couch_rep:update_rep_doc( - RepDoc, - [{<<"_replication_state">>, <<"error">>}, - {<<"_replication_id">>, ?l2b(BaseId)}]), - true = ets:delete(?REP_ID_TO_DOC_ID, BaseId), - true = ets:delete(?DOC_ID_TO_REP_ID, DocId), - {reply, ok, State}; - -handle_call(Msg, From, State) -> - ?LOG_ERROR("Replication manager received unexpected call ~p from ~p", - [Msg, From]), - {stop, {error, {unexpected_call, Msg}}, State}. - - -handle_cast({rep_db_changed, NewName}, #state{rep_db_name = NewName} = State) -> - {noreply, State}; - -handle_cast({rep_db_changed, _NewName}, State) -> - {noreply, restart(State)}; - -handle_cast({rep_db_created, NewName}, #state{rep_db_name = NewName} = State) -> - {noreply, State}; - -handle_cast({rep_db_created, _NewName}, State) -> - {noreply, restart(State)}; - -handle_cast({set_max_retries, MaxRetries}, State) -> - {noreply, State#state{max_retries = MaxRetries}}; - -handle_cast(Msg, State) -> - ?LOG_ERROR("Replication manager received unexpected cast ~p", [Msg]), - {stop, {error, {unexpected_cast, Msg}}, State}. - - -handle_info({'EXIT', From, normal}, #state{changes_feed_loop = From} = State) -> - % replicator DB deleted - {noreply, State#state{changes_feed_loop = nil, rep_db_name = nil}}; - -handle_info({'EXIT', From, Reason}, #state{db_notifier = From} = State) -> - ?LOG_ERROR("Database update notifier died. Reason: ~p", [Reason]), - {stop, {db_update_notifier_died, Reason}, State}; - -handle_info({'EXIT', From, normal}, #state{rep_start_pids = Pids} = State) -> - % one of the replication start processes terminated successfully - {noreply, State#state{rep_start_pids = Pids -- [From]}}; - -handle_info(Msg, State) -> - ?LOG_ERROR("Replication manager received unexpected message ~p", [Msg]), - {stop, {unexpected_msg, Msg}, State}. - - -terminate(_Reason, State) -> - #state{ - rep_start_pids = StartPids, - changes_feed_loop = Loop, - db_notifier = Notifier - } = State, - stop_all_replications(), - lists:foreach( - fun(Pid) -> - catch unlink(Pid), - catch exit(Pid, stop) - end, - [Loop | StartPids]), - true = ets:delete(?REP_ID_TO_DOC_ID), - true = ets:delete(?DOC_ID_TO_REP_ID), - couch_db_update_notifier:stop(Notifier). - - -code_change(_OldVsn, State, _Extra) -> - {ok, State}. - - -changes_feed_loop() -> - {ok, RepDb} = couch_rep:ensure_rep_db_exists(), - Server = self(), - Pid = spawn_link( - fun() -> - ChangesFeedFun = couch_changes:handle_changes( - #changes_args{ - include_docs = true, - feed = "continuous", - timeout = infinity, - db_open_options = [sys_db] - }, - {json_req, null}, - RepDb - ), - ChangesFeedFun( - fun({change, Change, _}, _) -> - case has_valid_rep_id(Change) of - true -> - ok = gen_server:call( - Server, {rep_db_update, Change}, infinity); - false -> - ok - end; - (_, _) -> - ok - end - ) - end - ), - couch_db:close(RepDb), - {Pid, couch_db:name(RepDb)}. - - -has_valid_rep_id({Change}) -> - has_valid_rep_id(get_value(<<"id">>, Change)); -has_valid_rep_id(<<?DESIGN_DOC_PREFIX, _Rest/binary>>) -> - false; -has_valid_rep_id(_Else) -> - true. - - -db_update_notifier() -> - Server = self(), - {ok, Notifier} = couch_db_update_notifier:start_link( - fun({created, DbName}) -> - case ?l2b(couch_config:get("replicator", "db", "_replicator")) of - DbName -> - ok = gen_server:cast(Server, {rep_db_created, DbName}); - _ -> - ok - end; - (_) -> - % no need to handle the 'deleted' event - the changes feed loop - % dies when the database is deleted - ok - end - ), - Notifier. - - -restart(#state{changes_feed_loop = Loop, rep_start_pids = StartPids} = State) -> - stop_all_replications(), - lists:foreach( - fun(Pid) -> - catch unlink(Pid), - catch exit(Pid, rep_db_changed) - end, - [Loop | StartPids]), - {NewLoop, NewRepDbName} = changes_feed_loop(), - State#state{ - changes_feed_loop = NewLoop, - rep_db_name = NewRepDbName, - rep_start_pids = [] - }. - - -process_update(State, {Change}) -> - {RepProps} = JsonRepDoc = get_value(doc, Change), - DocId = get_value(<<"_id">>, RepProps), - case get_value(<<"deleted">>, Change, false) of - true -> - rep_doc_deleted(DocId), - State; - false -> - case get_value(<<"_replication_state">>, RepProps) of - <<"completed">> -> - replication_complete(DocId), - State; - <<"error">> -> - stop_replication(DocId), - State; - <<"triggered">> -> - maybe_start_replication(State, DocId, JsonRepDoc); - undefined -> - maybe_start_replication(State, DocId, JsonRepDoc) - end - end. - - -rep_user_ctx({RepDoc}) -> - case get_value(<<"user_ctx">>, RepDoc) of - undefined -> - #user_ctx{}; - {UserCtx} -> - #user_ctx{ - name = get_value(<<"name">>, UserCtx, null), - roles = get_value(<<"roles">>, UserCtx, []) - } - end. - - -maybe_start_replication(#state{max_retries = MaxRetries} = State, - DocId, JsonRepDoc) -> - UserCtx = rep_user_ctx(JsonRepDoc), - {BaseId, _} = RepId = couch_rep:make_replication_id(JsonRepDoc, UserCtx), - case ets:lookup(?REP_ID_TO_DOC_ID, BaseId) of - [] -> - true = ets:insert(?REP_ID_TO_DOC_ID, {BaseId, {DocId, true}}), - true = ets:insert(?DOC_ID_TO_REP_ID, {DocId, {RepId, MaxRetries}}), - Server = self(), - Pid = spawn_link(fun() -> - start_replication(Server, JsonRepDoc, RepId, UserCtx, MaxRetries) - end), - State#state{rep_start_pids = [Pid | State#state.rep_start_pids]}; - [{BaseId, {DocId, _}}] -> - State; - [{BaseId, {OtherDocId, false}}] -> - ?LOG_INFO("The replication specified by the document `~s` was already" - " triggered by the document `~s`", [DocId, OtherDocId]), - maybe_tag_rep_doc(JsonRepDoc, ?l2b(BaseId)), - State; - [{BaseId, {OtherDocId, true}}] -> - ?LOG_INFO("The replication specified by the document `~s` is already" - " being triggered by the document `~s`", [DocId, OtherDocId]), - maybe_tag_rep_doc(JsonRepDoc, ?l2b(BaseId)), - State - end. - - -maybe_tag_rep_doc({Props} = JsonRepDoc, RepId) -> - case get_value(<<"_replication_id">>, Props) of - RepId -> - ok; - _ -> - couch_rep:update_rep_doc(JsonRepDoc, [{<<"_replication_id">>, RepId}]) - end. - - -start_replication(Server, {RepProps} = RepDoc, RepId, UserCtx, MaxRetries) -> - case (catch couch_rep:start_replication(RepDoc, RepId, UserCtx)) of - Pid when is_pid(Pid) -> - ?LOG_INFO("Document `~s` triggered replication `~s`", - [get_value(<<"_id">>, RepProps), pp_rep_id(RepId)]), - ok = gen_server:call(Server, {triggered, RepId}, infinity), - couch_rep:get_result(Pid, RepId, RepDoc, UserCtx); - Error -> - couch_rep:update_rep_doc( - RepDoc, - [{<<"_replication_state">>, <<"error">>}, - {<<"_replication_id">>, ?l2b(element(1, RepId))}]), - keep_retrying( - Server, RepId, RepDoc, UserCtx, Error, ?INITIAL_WAIT, MaxRetries) - end. - - -keep_retrying(Server, _RepId, RepDoc, _UserCtx, Error, _Wait, 0) -> - ok = gen_server:call(Server, {restart_failure, RepDoc, Error}, infinity); - -keep_retrying(Server, RepId, RepDoc, UserCtx, Error, Wait, RetriesLeft) -> - {RepProps} = RepDoc, - DocId = get_value(<<"_id">>, RepProps), - ?LOG_ERROR("Error starting replication `~s` (document `~s`): ~p. " - "Retrying in ~p seconds", [pp_rep_id(RepId), DocId, Error, Wait]), - ok = timer:sleep(Wait * 1000), - case (catch couch_rep:start_replication(RepDoc, RepId, UserCtx)) of - Pid when is_pid(Pid) -> - ok = gen_server:call(Server, {triggered, RepId}, infinity), - [{DocId, {RepId, MaxRetries}}] = ets:lookup(?DOC_ID_TO_REP_ID, DocId), - ?LOG_INFO("Document `~s` triggered replication `~s` after ~p attempts", - [DocId, pp_rep_id(RepId), MaxRetries - RetriesLeft + 1]), - couch_rep:get_result(Pid, RepId, RepDoc, UserCtx); - NewError -> - keep_retrying( - Server, RepId, RepDoc, UserCtx, NewError, Wait * 2, RetriesLeft - 1) - end. - - -rep_doc_deleted(DocId) -> - case stop_replication(DocId) of - {ok, RepId} -> - ?LOG_INFO("Stopped replication `~s` because replication document `~s`" - " was deleted", [pp_rep_id(RepId), DocId]); - none -> - ok - end. - - -replication_complete(DocId) -> - case stop_replication(DocId) of - {ok, RepId} -> - ?LOG_INFO("Replication `~s` finished (triggered by document `~s`)", - [pp_rep_id(RepId), DocId]); - none -> - ok - end. - - -stop_replication(DocId) -> - case ets:lookup(?DOC_ID_TO_REP_ID, DocId) of - [{DocId, {{BaseId, _} = RepId, _MaxRetries}}] -> - couch_rep:end_replication(RepId), - true = ets:delete(?REP_ID_TO_DOC_ID, BaseId), - true = ets:delete(?DOC_ID_TO_REP_ID, DocId), - {ok, RepId}; - [] -> - none - end. - - -stop_all_replications() -> - ?LOG_INFO("Stopping all ongoing replications because the replicator" - " database was deleted or changed", []), - ets:foldl( - fun({_, {RepId, _}}, _) -> - couch_rep:end_replication(RepId) - end, - ok, ?DOC_ID_TO_REP_ID), - true = ets:delete_all_objects(?REP_ID_TO_DOC_ID), - true = ets:delete_all_objects(?DOC_ID_TO_REP_ID). - - -% pretty-print replication id -pp_rep_id({Base, Extension}) -> - Base ++ Extension. |