From 544a38dd45f6a58d34296c6c768afd086eb2ac70 Mon Sep 17 00:00:00 2001 From: Christopher Lenz Date: Fri, 28 Mar 2008 23:32:19 +0000 Subject: Imported trunk. git-svn-id: https://svn.apache.org/repos/asf/incubator/couchdb/trunk@642432 13f79535-47bb-0310-9956-ffa450edef68 --- src/couch_inets/httpd_manager.erl | 829 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 829 insertions(+) create mode 100644 src/couch_inets/httpd_manager.erl (limited to 'src/couch_inets/httpd_manager.erl') diff --git a/src/couch_inets/httpd_manager.erl b/src/couch_inets/httpd_manager.erl new file mode 100644 index 00000000..b7529f37 --- /dev/null +++ b/src/couch_inets/httpd_manager.erl @@ -0,0 +1,829 @@ +%% ``The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved via the world wide web at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. +%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings +%% AB. All Rights Reserved.'' +%% +%% $Id$ +%% + +-module(httpd_manager). + +-include("httpd.hrl"). + +-behaviour(gen_server). + +%% External API +-export([start/2, start_link/2, start_link/3, stop/1, restart/1]). + +%% Internal API +-export([new_connection/1, done_connection/1]). + +%% Module API +-export([config_lookup/2, config_lookup/3, + config_multi_lookup/2, config_multi_lookup/3, + config_match/2, config_match/3]). + +%% gen_server exports +-export([init/1, + handle_call/3, handle_cast/2, handle_info/2, + terminate/2, + code_change/3]). + + +%% Management exports +-export([block/2, block/3, unblock/1]). +-export([get_admin_state/1, get_usage_state/1]). +-export([is_busy/1,is_busy/2,is_busy_or_blocked/1,is_blocked/1]). %% ??????? +-export([get_status/1, get_status/2]). + +-export([c/1]). + +-record(state,{socket_type = ip_comm, + config_file, + config_db = null, + connections, %% Current request handlers + admin_state = unblocked, + blocker_ref = undefined, + blocking_tmr = undefined, + status = []}). + + +c(Port) -> + Ref = httpd_util:make_name("httpd",undefined,Port), + gen_server:call(Ref, fake_close). + + +%% +%% External API +%% + +start(ConfigFile, ConfigList) -> + Port = httpd_util:key1search(ConfigList,port,80), + Addr = httpd_util:key1search(ConfigList,bind_address), + Name = make_name(Addr,Port), + gen_server:start({local,Name},?MODULE, + [ConfigFile, ConfigList, 15000, Addr, Port],[]). + +start_link(ConfigFile, ConfigList) -> + start_link(ConfigFile, ConfigList, 15000). +start_link(ConfigFile, ConfigList, AcceptTimeout) -> + Port = httpd_util:key1search(ConfigList,port,80), + Addr = httpd_util:key1search(ConfigList,bind_address), + Name = make_name(Addr,Port), + gen_server:start_link({local, Name},?MODULE, + [ConfigFile, ConfigList, AcceptTimeout, Addr, Port],[]). + +stop(ServerRef) -> + gen_server:call(ServerRef, stop). + +restart(ServerRef) -> + gen_server:call(ServerRef, restart). + + +%%%---------------------------------------------------------------- + +block(ServerRef, disturbing) -> + call(ServerRef,block); + +block(ServerRef, non_disturbing) -> + do_block(ServerRef, non_disturbing, infinity). + +block(ServerRef, Method, Timeout) -> + do_block(ServerRef, Method, Timeout). + + +%% The reason for not using call here, is that the manager cannot +%% _wait_ for completion of the requests. It must be able to do +%% do other things at the same time as the blocking goes on. +do_block(ServerRef, Method, infinity) -> + Ref = make_ref(), + cast(ServerRef, {block, Method, infinity, self(), Ref}), + receive + {block_reply, Reply, Ref} -> + Reply + end; +do_block(ServerRef,Method,Timeout) when Timeout > 0 -> + Ref = make_ref(), + cast(ServerRef,{block,Method,Timeout,self(),Ref}), + receive + {block_reply,Reply,Ref} -> + Reply + end. + + +%%%---------------------------------------------------------------- + +%% unblock + +unblock(ServerRef) -> + call(ServerRef,unblock). + +%% get admin/usage state + +get_admin_state(ServerRef) -> + call(ServerRef,get_admin_state). + +get_usage_state(ServerRef) -> + call(ServerRef,get_usage_state). + + +%% get_status + +get_status(ServerRef) -> + gen_server:call(ServerRef,get_status). + +get_status(ServerRef,Timeout) -> + gen_server:call(ServerRef,get_status,Timeout). + +%% +%% Internal API +%% + + +%% new_connection + +new_connection(Manager) -> + gen_server:call(Manager, {new_connection, self()}, infinity). + +%% done + +done_connection(Manager) -> + gen_server:cast(Manager, {done_connection, self()}). + + +%% is_busy(ServerRef) -> true | false +%% +%% Tests if the server is (in usage state) busy, +%% i.e. has rached the heavy load limit. +%% + +is_busy(ServerRef) -> + gen_server:call(ServerRef,is_busy). + +is_busy(ServerRef,Timeout) -> + gen_server:call(ServerRef,is_busy,Timeout). + + +%% is_busy_or_blocked(ServerRef) -> busy | blocked | false +%% +%% Tests if the server is busy (usage state), i.e. has rached, +%% the heavy load limit, or blocked (admin state) . +%% + +is_busy_or_blocked(ServerRef) -> + gen_server:call(ServerRef,is_busy_or_blocked). + + +%% is_blocked(ServerRef) -> true | false +%% +%% Tests if the server is blocked (admin state) . +%% + +is_blocked(ServerRef) -> + gen_server:call(ServerRef,is_blocked). + + +%% +%% Module API. Theese functions are intended for use from modules only. +%% + +config_lookup(Port, Query) -> + config_lookup(undefined, Port, Query). +config_lookup(Addr, Port, Query) -> + Name = httpd_util:make_name("httpd",Addr,Port), + gen_server:call(whereis(Name), {config_lookup, Query}). + +config_multi_lookup(Port, Query) -> + config_multi_lookup(undefined,Port,Query). +config_multi_lookup(Addr,Port, Query) -> + Name = httpd_util:make_name("httpd",Addr,Port), + gen_server:call(whereis(Name), {config_multi_lookup, Query}). + +config_match(Port, Pattern) -> + config_match(undefined,Port,Pattern). +config_match(Addr, Port, Pattern) -> + Name = httpd_util:make_name("httpd",Addr,Port), + gen_server:call(whereis(Name), {config_match, Pattern}). + + +%% +%% Server call-back functions +%% + +%% init + +init([ConfigFile, ConfigList, AcceptTimeout, Addr, Port]) -> + process_flag(trap_exit, true), + case (catch do_init(ConfigFile, ConfigList, AcceptTimeout, Addr, Port)) of + {error, Reason} -> + String = lists:flatten(io_lib:format("Failed initiating web server: ~n~p~n~p~n",[ConfigFile,Reason])), + error_logger:error_report(String), + {stop, Reason}; + {ok, State} -> + {ok, State} + end. + + +do_init(ConfigFile, ConfigList, AcceptTimeout, Addr, Port) -> + ConfigDB = do_initial_store(ConfigList), + SocketType = httpd_conf:config(ConfigDB), + case httpd_acceptor_sup:start_acceptor(SocketType, Addr, + Port, ConfigDB, AcceptTimeout) of + {ok, _Pid} -> + Status = [{max_conn,0}, {last_heavy_load,never}, + {last_connection,never}], + State = #state{socket_type = SocketType, + config_file = ConfigFile, + config_db = ConfigDB, + connections = [], + status = Status}, + {ok, State}; + Else -> + Else + end. + + +do_initial_store(ConfigList) -> + case httpd_conf:store(ConfigList) of + {ok, ConfigDB} -> + ConfigDB; + {error, Reason} -> + throw({error, Reason}) + end. + + + +%% handle_call + +handle_call(stop, _From, State) -> + {stop, normal, ok, State}; + +handle_call({config_lookup, Query}, _From, State) -> + Res = httpd_util:lookup(State#state.config_db, Query), + {reply, Res, State}; + +handle_call({config_multi_lookup, Query}, _From, State) -> + Res = httpd_util:multi_lookup(State#state.config_db, Query), + {reply, Res, State}; + +handle_call({config_match, Query}, _From, State) -> + Res = ets:match_object(State#state.config_db, Query), + {reply, Res, State}; + +handle_call(get_status, _From, State) -> + ManagerStatus = manager_status(self()), + S1 = [{current_conn,length(State#state.connections)}|State#state.status]++ + [ManagerStatus], + {reply,S1,State}; + +handle_call(is_busy, _From, State) -> + Reply = case get_ustate(State) of + busy -> + true; + _ -> + false + end, + {reply,Reply,State}; + +handle_call(is_busy_or_blocked, _From, State) -> + Reply = + case get_astate(State) of + unblocked -> + case get_ustate(State) of + busy -> + busy; + _ -> + false + end; + _ -> + blocked + end, + {reply,Reply,State}; + +handle_call(is_blocked, _From, State) -> + Reply = + case get_astate(State) of + unblocked -> + false; + _ -> + true + end, + {reply,Reply,State}; + +handle_call(get_admin_state, _From, State) -> + Reply = get_astate(State), + {reply,Reply,State}; + +handle_call(get_usage_state, _From, State) -> + Reply = get_ustate(State), + {reply,Reply,State}; + +handle_call(restart, _From, State) when State#state.admin_state == blocked -> + case handle_restart(State) of + {stop, Reply,S1} -> + {stop, Reply, S1}; + {_, Reply, S1} -> + {reply,Reply,S1} + end; + +handle_call(restart, _From, State) -> + {reply,{error,{invalid_admin_state,State#state.admin_state}},State}; + +handle_call(block, _From, State) -> + {Reply,S1} = handle_block(State), + {reply,Reply,S1}; + +handle_call(unblock, {From,_Tag}, State) -> + {Reply,S1} = handle_unblock(State,From), + {reply, Reply, S1}; + +handle_call({new_connection, Pid}, _From, State) -> + {Status, NewState} = handle_new_connection(State, Pid), + {reply, Status, NewState}; + +handle_call(Request, From, State) -> + String = + lists:flatten( + io_lib:format("Unknown request " + "~n ~p" + "~nto manager (~p)" + "~nfrom ~p", + [Request, self(), From])), + report_error(State,String), + {reply, ok, State}. + + +%% handle_cast + +handle_cast({done_connection, Pid}, State) -> + S1 = handle_done_connection(State, Pid), + {noreply, S1}; + +handle_cast({block, disturbing, Timeout, From, Ref}, State) -> + S1 = handle_block(State, Timeout, From, Ref), + {noreply,S1}; + +handle_cast({block, non_disturbing, Timeout, From, Ref}, State) -> + S1 = handle_nd_block(State, Timeout, From, Ref), + {noreply,S1}; + +handle_cast(Message, State) -> + String = + lists:flatten( + io_lib:format("Unknown message " + "~n ~p" + "~nto manager (~p)", + [Message, self()])), + report_error(State, String), + {noreply, State}. + +%% handle_info + +handle_info({block_timeout, Method}, State) -> + S1 = handle_block_timeout(State,Method), + {noreply, S1}; + +handle_info({'DOWN', Ref, process, _Object, _Info}, State) -> + S1 = + case State#state.blocker_ref of + Ref -> + handle_blocker_exit(State); + _ -> + %% Not our blocker, so ignore + State + end, + {noreply, S1}; + +handle_info({'EXIT', _, normal}, State) -> + {noreply, State}; + +handle_info({'EXIT', _, blocked}, S) -> + {noreply, S}; + +handle_info({'EXIT', Pid, Reason}, State) -> + S1 = check_connections(State, Pid, Reason), + {noreply, S1}; + +handle_info(Info, State) -> + String = + lists:flatten( + io_lib:format("Unknown info " + "~n ~p" + "~nto manager (~p)", + [Info, self()])), + report_error(State, String), + {noreply, State}. + + +%% terminate + +terminate(_, #state{config_db = Db}) -> + httpd_conf:remove_all(Db), + ok. + + +%% code_change({down,ToVsn}, State, Extra) +%% +%% NOTE: +%% Actually upgrade from 2.5.1 to 2.5.3 and downgrade from +%% 2.5.3 to 2.5.1 is done with an application restart, so +%% these function is actually never used. The reason for keeping +%% this stuff is only for future use. +%% +code_change({down,_ToVsn}, State, _Extra) -> + {ok,State}; + +%% code_change(FromVsn, State, Extra) +%% +code_change(_FromVsn, State, _Extra) -> + {ok,State}. + + + +%% ------------------------------------------------------------------------- +%% check_connection +%% +%% +%% +%% + +check_connections(#state{connections = []} = State, _Pid, _Reason) -> + State; +check_connections(#state{admin_state = shutting_down, + connections = Connections} = State, Pid, Reason) -> + %% Could be a crashing request handler + case lists:delete(Pid, Connections) of + [] -> % Crashing request handler => block complete + String = + lists:flatten( + io_lib:format("request handler (~p) crashed:" + "~n ~p", [Pid, Reason])), + report_error(State, String), + demonitor_blocker(State#state.blocker_ref), + {Tmr,From,Ref} = State#state.blocking_tmr, + stop_block_tmr(Tmr), + From ! {block_reply,ok,Ref}, + State#state{admin_state = blocked, connections = [], + blocker_ref = undefined}; + Connections1 -> + State#state{connections = Connections1} + end; +check_connections(#state{connections = Connections} = State, Pid, Reason) -> + case lists:delete(Pid, Connections) of + Connections -> % Not a request handler, so ignore + State; + NewConnections -> + String = + lists:flatten( + io_lib:format("request handler (~p) crashed:" + "~n ~p", [Pid, Reason])), + report_error(State, String), + State#state{connections = NewConnections} + end. + + +%% ------------------------------------------------------------------------- +%% handle_[new | done]_connection +%% +%% +%% +%% + +handle_new_connection(State, Handler) -> + UsageState = get_ustate(State), + AdminState = get_astate(State), + handle_new_connection(UsageState, AdminState, State, Handler). + +handle_new_connection(busy, unblocked, State, _Handler) -> + Status = update_heavy_load_status(State#state.status), + {{reject, busy}, + State#state{status = Status}}; + +handle_new_connection(_UsageState, unblocked, State, Handler) -> + Connections = State#state.connections, + Status = update_connection_status(State#state.status, + length(Connections)+1), + link(Handler), + {{ok, accept}, + State#state{connections = [Handler|Connections], status = Status}}; + +handle_new_connection(_UsageState, _AdminState, State, _Handler) -> + {{reject, blocked}, + State}. + +handle_done_connection(#state{admin_state = shutting_down, + connections = Connections} = State, Handler) -> + unlink(Handler), + case lists:delete(Handler, Connections) of + [] -> % Ok, block complete + demonitor_blocker(State#state.blocker_ref), + {Tmr,From,Ref} = State#state.blocking_tmr, + stop_block_tmr(Tmr), + From ! {block_reply,ok,Ref}, + State#state{admin_state = blocked, connections = [], + blocker_ref = undefined}; + Connections1 -> + State#state{connections = Connections1} + end; + +handle_done_connection(#state{connections = Connections} = State, Handler) -> + State#state{connections = lists:delete(Handler, Connections)}. + + +%% ------------------------------------------------------------------------- +%% handle_block +%% +%% +%% +%% +handle_block(#state{admin_state = AdminState} = S) -> + handle_block(S, AdminState). + +handle_block(S,unblocked) -> + %% Kill all connections + [kill_handler(Pid) || Pid <- S#state.connections], + {ok,S#state{connections = [], admin_state = blocked}}; +handle_block(S,blocked) -> + {ok,S}; +handle_block(S,shutting_down) -> + {{error,shutting_down},S}. + + +kill_handler(Pid) -> + exit(Pid, blocked). + +handle_block(S,Timeout,From,Ref) when Timeout >= 0 -> + do_block(S,Timeout,From,Ref); + +handle_block(S,Timeout,From,Ref) -> + Reply = {error,{invalid_block_request,Timeout}}, + From ! {block_reply,Reply,Ref}, + S. + +do_block(S,Timeout,From,Ref) -> + case S#state.connections of + [] -> + %% Already in idle usage state => go directly to blocked + From ! {block_reply,ok,Ref}, + S#state{admin_state = blocked}; + _ -> + %% Active or Busy usage state => go to shutting_down + %% Make sure we get to know if blocker dies... + MonitorRef = monitor_blocker(From), + Tmr = {start_block_tmr(Timeout,disturbing),From,Ref}, + S#state{admin_state = shutting_down, + blocker_ref = MonitorRef, blocking_tmr = Tmr} + end. + +handle_nd_block(S,infinity,From,Ref) -> + do_nd_block(S,infinity,From,Ref); + +handle_nd_block(S,Timeout,From,Ref) when Timeout >= 0 -> + do_nd_block(S,Timeout,From,Ref); + +handle_nd_block(S,Timeout,From,Ref) -> + Reply = {error,{invalid_block_request,Timeout}}, + From ! {block_reply,Reply,Ref}, + S. + +do_nd_block(S,Timeout,From,Ref) -> + case S#state.connections of + [] -> + %% Already in idle usage state => go directly to blocked + From ! {block_reply,ok,Ref}, + S#state{admin_state = blocked}; + _ -> + %% Active or Busy usage state => go to shutting_down + %% Make sure we get to know if blocker dies... + MonitorRef = monitor_blocker(From), + Tmr = {start_block_tmr(Timeout,non_disturbing),From,Ref}, + S#state{admin_state = shutting_down, + blocker_ref = MonitorRef, blocking_tmr = Tmr} + end. + +handle_block_timeout(S,Method) -> + %% Time to take this to the road... + demonitor_blocker(S#state.blocker_ref), + handle_block_timeout1(S,Method,S#state.blocking_tmr). + +handle_block_timeout1(S,non_disturbing,{_,From,Ref}) -> + From ! {block_reply,{error,timeout},Ref}, + S#state{admin_state = unblocked, + blocker_ref = undefined, blocking_tmr = undefined}; + +handle_block_timeout1(S,disturbing,{_,From,Ref}) -> + [exit(Pid,blocked) || Pid <- S#state.connections], + + From ! {block_reply,ok,Ref}, + S#state{admin_state = blocked, connections = [], + blocker_ref = undefined, blocking_tmr = undefined}; + +handle_block_timeout1(S,Method,{_,From,Ref}) -> + From ! {block_reply,{error,{unknown_block_method,Method}},Ref}, + S#state{admin_state = blocked, connections = [], + blocker_ref = undefined, blocking_tmr = undefined}; + +handle_block_timeout1(S, _Method, _TmrInfo) -> + S#state{admin_state = unblocked, + blocker_ref = undefined, blocking_tmr = undefined}. + +handle_unblock(S, FromA) -> + handle_unblock(S, FromA, S#state.admin_state). + +handle_unblock(S, _FromA, unblocked) -> + {ok,S}; +handle_unblock(S, FromA, _AdminState) -> + stop_block_tmr(S#state.blocking_tmr), + case S#state.blocking_tmr of + {_Tmr,FromB,Ref} -> + %% Another process is trying to unblock + %% Inform the blocker + FromB ! {block_reply, {error,{unblocked,FromA}},Ref}; + _ -> + ok + end, + {ok,S#state{admin_state = unblocked, blocking_tmr = undefined}}. + +%% The blocker died so we give up on the block. +handle_blocker_exit(S) -> + {Tmr,_From,_Ref} = S#state.blocking_tmr, + stop_block_tmr(Tmr), + S#state{admin_state = unblocked, + blocker_ref = undefined, blocking_tmr = undefined}. + + + +%% ------------------------------------------------------------------------- +%% handle_restart +%% +%% +%% +%% +handle_restart(#state{config_file = undefined} = State) -> + {continue, {error, undefined_config_file}, State}; +handle_restart(#state{config_db = Db, config_file = ConfigFile} = State) -> + {ok, Config} = httpd_conf:load(ConfigFile), + case (catch check_constant_values(Db, Config)) of + ok -> + %% If something goes wrong between the remove + %% and the store where fu-ed + httpd_conf:remove_all(Db), + case httpd_conf:store(Config) of + {ok, NewConfigDB} -> + {continue, ok, State#state{config_db = NewConfigDB}}; + Error -> + {stop, Error, State} + end; + Error -> + {continue, Error, State} + end. + + +check_constant_values(Db, Config) -> + %% Check port number + Port = httpd_util:lookup(Db,port), + case httpd_util:key1search(Config,port) of %% MUST be equal + Port -> + ok; + OtherPort -> + throw({error,{port_number_changed,Port,OtherPort}}) + end, + + %% Check bind address + Addr = httpd_util:lookup(Db,bind_address), + case httpd_util:key1search(Config,bind_address) of %% MUST be equal + Addr -> + ok; + OtherAddr -> + throw({error,{addr_changed,Addr,OtherAddr}}) + end, + + %% Check socket type + SockType = httpd_util:lookup(Db, com_type), + case httpd_util:key1search(Config, com_type) of %% MUST be equal + SockType -> + ok; + OtherSockType -> + throw({error,{sock_type_changed,SockType,OtherSockType}}) + end, + ok. + + +%% get_ustate(State) -> idle | active | busy +%% +%% Retrieve the usage state of the HTTP server: +%% 0 active connection -> idle +%% max_clients active connections -> busy +%% Otherwise -> active +%% +get_ustate(State) -> + get_ustate(length(State#state.connections),State). + +get_ustate(0,_State) -> + idle; +get_ustate(ConnectionCnt,State) -> + ConfigDB = State#state.config_db, + case httpd_util:lookup(ConfigDB, max_clients, 150) of + ConnectionCnt -> + busy; + _ -> + active + end. + + +get_astate(S) -> S#state.admin_state. + + +%% Timer handling functions +start_block_tmr(infinity,_) -> + undefined; +start_block_tmr(T,M) -> + erlang:send_after(T,self(),{block_timeout,M}). + +stop_block_tmr(undefined) -> + ok; +stop_block_tmr(Ref) -> + erlang:cancel_timer(Ref). + + +%% Monitor blocker functions +monitor_blocker(Pid) when pid(Pid) -> + case (catch erlang:monitor(process,Pid)) of + {'EXIT', _Reason} -> + undefined; + MonitorRef -> + MonitorRef + end; +monitor_blocker(_) -> + undefined. + +demonitor_blocker(undefined) -> + ok; +demonitor_blocker(Ref) -> + (catch erlang:demonitor(Ref)). + + +%% Some status utility functions + +update_heavy_load_status(Status) -> + update_status_with_time(Status,last_heavy_load). + +update_connection_status(Status,ConnCount) -> + S1 = case lists:keysearch(max_conn,1,Status) of + {value, {max_conn, C1}} when ConnCount > C1 -> + lists:keyreplace(max_conn,1,Status,{max_conn,ConnCount}); + {value, {max_conn, _C2}} -> + Status; + false -> + [{max_conn, ConnCount} | Status] + end, + update_status_with_time(S1,last_connection). + +update_status_with_time(Status,Key) -> + lists:keyreplace(Key,1,Status,{Key,universal_time()}). + +universal_time() -> calendar:universal_time(). + +manager_status(P) -> + Items = [status, message_queue_len, reductions, + heap_size, stack_size], + {manager_status, process_status(P,Items,[])}. + + +process_status(P,[],L) -> + [{pid,P}|lists:reverse(L)]; +process_status(P,[H|T],L) -> + case (catch process_info(P,H)) of + {H, Value} -> + process_status(P,T,[{H,Value}|L]); + _ -> + process_status(P,T,[{H,undefined}|L]) + end. + +make_name(Addr,Port) -> + httpd_util:make_name("httpd",Addr,Port). + + +report_error(State,String) -> + Cdb = State#state.config_db, + error_logger:error_report(String), + mod_log:report_error(Cdb,String), + mod_disk_log:report_error(Cdb,String). + +%% +call(ServerRef,Request) -> + gen_server:call(ServerRef,Request). + +cast(ServerRef,Message) -> + gen_server:cast(ServerRef,Message). + -- cgit v1.2.3