PoC Couch Stats Resource Tracker for tracking process local resource usage

src/chttpd/src/chttpd.erl

@@ -221,6 +221,7 @@ stop() ->
     mochiweb_http:stop(?MODULE).
 
 handle_request(MochiReq0) ->
+    couch_util:clear_pdict(), %% Make sure we start clean, everytime
     erlang:put(?REWRITE_COUNT, 0),
     MochiReq = couch_httpd_vhost:dispatch_host(MochiReq0),
     handle_request_int(MochiReq).
@@ -323,6 +324,9 @@ handle_request_int(MochiReq) ->
     % Save client socket so that it can be monitored for disconnects
     chttpd_util:mochiweb_client_req_set(MochiReq),
 
+    %% This is probably better in before_request, but having Path is nice
+    couch_stats_resource_tracker:create_coordinator_context(HttpReq0, Path),
+
     {HttpReq2, Response} =
         case before_request(HttpReq0) of
             {ok, HttpReq1} ->
@@ -347,12 +351,14 @@ handle_request_int(MochiReq) ->
         #httpd_resp{status = ok, response = Resp} ->
             {ok, Resp};
         #httpd_resp{status = aborted, reason = Reason} ->
-            couch_log:error("Response abnormally terminated: ~p", [Reason]),
+            couch_log:error("Response abnormally terminated: ~w", [Reason]),
             exit({shutdown, Reason})
     end.
 
 before_request(HttpReq) ->
     try
+        %% TODO: re-enable this here once we have Path
+        %% couch_stats_resource_tracker:create_coordinator_context(HttpReq),
         chttpd_stats:init(),
         chttpd_plugin:before_request(HttpReq)
     catch
@@ -372,6 +378,7 @@ after_request(HttpReq, HttpResp0) ->
     HttpResp2 = update_stats(HttpReq, HttpResp1),
     chttpd_stats:report(HttpReq, HttpResp2),
     maybe_log(HttpReq, HttpResp2),
+    %%couch_stats_resource_tracker:close_context(),
     HttpResp2.
 
 process_request(#httpd{mochi_req = MochiReq} = HttpReq) ->
@@ -409,6 +416,7 @@ handle_req_after_auth(HandlerKey, HttpReq) ->
             HandlerKey,
             fun chttpd_db:handle_request/1
         ),
+        couch_stats_resource_tracker:set_context_handler_fun(HandlerFun),
         AuthorizedReq = chttpd_auth:authorize(
             possibly_hack(HttpReq),
             fun chttpd_auth_request:authorize_request/1

src/chttpd/src/chttpd_db.erl

@@ -83,6 +83,7 @@
 
 % Database request handlers
 handle_request(#httpd{path_parts = [DbName | RestParts], method = Method} = Req) ->
+    couch_stats_resource_tracker:set_context_dbname(DbName),
     case {Method, RestParts} of
         {'PUT', []} ->
             create_db_req(Req, DbName);
@@ -2248,7 +2249,7 @@ monitor_attachments(Att) ->
     monitor_attachments([Att]).
 
 demonitor_refs(Refs) when is_list(Refs) ->
-    [demonitor(Ref) || Ref <- Refs].
+    [demonitor(Ref, [flush]) || Ref <- Refs].
 
 % Return attachments which are not stubs
 non_stubbed_attachments(Atts) when is_list(Atts) ->

src/chttpd/src/chttpd_httpd_handlers.erl

@@ -20,6 +20,7 @@ url_handler(<<"_utils">>) -> fun chttpd_misc:handle_utils_dir_req/1;
 url_handler(<<"_all_dbs">>) -> fun chttpd_misc:handle_all_dbs_req/1;
 url_handler(<<"_dbs_info">>) -> fun chttpd_misc:handle_dbs_info_req/1;
 url_handler(<<"_active_tasks">>) -> fun chttpd_misc:handle_task_status_req/1;
+url_handler(<<"_active_resources">>) -> fun chttpd_misc:handle_resource_status_req/1;
 url_handler(<<"_scheduler">>) -> fun couch_replicator_httpd:handle_scheduler_req/1;
 url_handler(<<"_node">>) -> fun chttpd_node:handle_node_req/1;
 url_handler(<<"_reload_query_servers">>) -> fun chttpd_misc:handle_reload_query_servers_req/1;

src/chttpd/src/chttpd_misc.erl

@@ -20,6 +20,7 @@
     handle_replicate_req/1,
     handle_reload_query_servers_req/1,
     handle_task_status_req/1,
+    handle_resource_status_req/1,
     handle_up_req/1,
     handle_utils_dir_req/1,
     handle_utils_dir_req/2,
@@ -36,8 +37,7 @@
     [
         send_json/2, send_json/3,
         send_method_not_allowed/2,
-        send_chunk/2,
-        start_chunked_response/3
+        send_chunk/2
     ]
 ).
 
@@ -230,6 +230,110 @@ handle_task_status_req(#httpd{method = 'GET'} = Req) ->
 handle_task_status_req(Req) ->
     send_method_not_allowed(Req, "GET,HEAD").
 
+handle_resource_status_req(#httpd{method = 'POST'} = Req) ->
+    ok = chttpd:verify_is_server_admin(Req),
+    chttpd:validate_ctype(Req, "application/json"),
+    {Props} = chttpd:json_body_obj(Req),
+    Action = proplists:get_value(<<"action">>, Props),
+    Key = proplists:get_value(<<"key">>, Props),
+    Val = proplists:get_value(<<"val">>, Props),
+
+    CountBy = fun couch_stats_resource_tracker:count_by/1,
+    GroupBy = fun couch_stats_resource_tracker:group_by/2,
+    SortedBy1 = fun couch_stats_resource_tracker:sorted_by/1,
+    SortedBy2 = fun couch_stats_resource_tracker:sorted_by/2,
+    ConvertEle = fun(K) -> list_to_existing_atom(binary_to_list(K)) end,
+    ConvertList = fun(L) -> [ConvertEle(E) || E <- L] end,
+    ToJson = fun couch_stats_resource_tracker:term_to_flat_json/1,
+    JsonKeys = fun(PL) -> [[ToJson(K), V] || {K, V} <- PL] end,
+
+    Fun = case {Action, Key, Val} of
+        {<<"count_by">>, Keys, undefined} when is_list(Keys) ->
+            Keys1 = [ConvertEle(K) || K <- Keys],
+            fun() -> CountBy(Keys1) end;
+        {<<"count_by">>, Key, undefined} ->
+            Key1 = ConvertEle(Key),
+            fun() -> CountBy(Key1) end;
+        {<<"group_by">>, Keys, Vals} when is_list(Keys) andalso is_list(Vals) ->
+            Keys1 = ConvertList(Keys),
+            Vals1 = ConvertList(Vals),
+            fun() -> GroupBy(Keys1, Vals1) end;
+        {<<"group_by">>, Key, Vals} when is_list(Vals) ->
+            Key1 = ConvertEle(Key),
+            Vals1 = ConvertList(Vals),
+            fun() -> GroupBy(Key1, Vals1) end;
+        {<<"group_by">>, Keys, Val} when is_list(Keys) ->
+            Keys1 = ConvertList(Keys),
+            Val1 = ConvertEle(Val),
+            fun() -> GroupBy(Keys1, Val1) end;
+        {<<"group_by">>, Key, Val} ->
+            Key1 = ConvertEle(Key),
+            Val1 = ConvertList(Val),
+            fun() -> GroupBy(Key1, Val1) end;
+
+        {<<"sorted_by">>, Key, undefined} ->
+            Key1 = ConvertEle(Key),
+            fun() -> JsonKeys(SortedBy1(Key1)) end;
+        {<<"sorted_by">>, Keys, undefined} when is_list(Keys) ->
+            Keys1 = [ConvertEle(K) || K <- Keys],
+            fun() -> JsonKeys(SortedBy1(Keys1)) end;
+        {<<"sorted_by">>, Keys, Vals} when is_list(Keys) andalso is_list(Vals) ->
+            Keys1 = ConvertList(Keys),
+            Vals1 = ConvertList(Vals),
+            fun() -> JsonKeys(SortedBy2(Keys1, Vals1)) end;
+        {<<"sorted_by">>, Key, Vals} when is_list(Vals) ->
+            Key1 = ConvertEle(Key),
+            Vals1 = ConvertList(Vals),
+            fun() -> JsonKeys(SortedBy2(Key1, Vals1)) end;
+        {<<"sorted_by">>, Keys, Val} when is_list(Keys) ->
+            Keys1 = ConvertList(Keys),
+            Val1 = ConvertEle(Val),
+            fun() -> JsonKeys(SortedBy2(Keys1, Val1)) end;
+        {<<"sorted_by">>, Key, Val} ->
+            Key1 = ConvertEle(Key),
+            Val1 = ConvertList(Val),
+            fun() -> JsonKeys(SortedBy2(Key1, Val1)) end;
+        _ ->
+            throw({badrequest, invalid_resource_request})
+    end,
+
+    Fun1 = fun() ->
+        case Fun() of
+            Map when is_map(Map) ->
+                {maps:fold(
+                    fun
+                        (_K,0,A) -> A; %% TODO: Skip 0 value entries?
+                        (K,V,A) -> [{ToJson(K), V} | A]
+                    end,
+                    [], Map)};
+            List when is_list(List) ->
+                List
+        end
+    end,
+
+    {Resp, _Bad} = rpc:multicall(erlang, apply, [
+        fun() ->
+            {node(), Fun1()}
+        end,
+        []
+    ]),
+    %%io:format("{CSRT}***** GOT RESP: ~p~n", [Resp]),
+    send_json(Req, {Resp});
+handle_resource_status_req(#httpd{method = 'GET'} = Req) ->
+    ok = chttpd:verify_is_server_admin(Req),
+    {Resp, Bad} = rpc:multicall(erlang, apply, [
+        fun() ->
+            {node(), couch_stats_resource_tracker:active()}
+        end,
+        []
+    ]),
+    %% TODO: incorporate Bad responses
+    io:format("ACTIVE RESP: ~p~nBAD RESP: ~p~n", [Resp, Bad]),
+    send_json(Req, {Resp});
+handle_resource_status_req(Req) ->
+    ok = chttpd:verify_is_server_admin(Req),
+    send_method_not_allowed(Req, "GET,HEAD,POST").
+
 handle_replicate_req(#httpd{method = 'POST', user_ctx = Ctx, req_body = PostBody} = Req) ->
     chttpd:validate_ctype(Req, "application/json"),
     %% see HACK in chttpd.erl about replication

src/chttpd/test/eunit/chttpd_db_doc_size_tests.erl

@@ -25,7 +25,7 @@
 setup() ->
     Hashed = couch_passwords:hash_admin_password(?PASS),
     ok = config:set("admins", ?USER, ?b2l(Hashed), _Persist = false),
-    ok = config:set("couchdb", "max_document_size", "50"),
+    ok = config:set("couchdb", "max_document_size", "50", false),
     TmpDb = ?tempdb(),
     Addr = config:get("chttpd", "bind_address", "127.0.0.1"),
     Port = mochiweb_socket_server:get(chttpd, port),

src/couch/include/couch_db.hrl

@@ -127,6 +127,7 @@
     meta = []
 }).
 
+-define(LOG_UNEXPECTED_MSG(Msg), couch_log:warning("[~p:~p:~p/~p]{~p[~p]} Unexpected message: ~w", [?MODULE, ?LINE, ?FUNCTION_NAME, ?FUNCTION_ARITY, self(), element(2, process_info(self(), message_queue_len)), Msg])).
 
 -record(user_ctx, {
     name=null,

src/couch/priv/stats_descriptions.cfg

@@ -298,6 +298,10 @@
     {type, counter},
     {desc, <<"number of couch_server LRU operations skipped">>}
 ]}.
+{[couchdb, couch_server, open], [
+    {type, counter},
+    {desc, <<"number of couch_server open operations invoked">>}
+]}.
 {[couchdb, query_server, vdu_rejects], [
     {type, counter},
     {desc, <<"number of rejections by validate_doc_update function">>}
@@ -410,10 +414,39 @@
     {type, counter},
     {desc, <<"number of other requests">>}
 ]}.
+{[couchdb, query_server, js_filter], [
+    {type, counter},
+    {desc, <<"number of JS filter invocations">>}
+]}.
+{[couchdb, query_server, js_filtered_docs], [
+    {type, counter},
+    {desc, <<"number of docs filtered through JS invocations">>}
+]}.
+{[couchdb, query_server, js_filter_error], [
+    {type, counter},
+    {desc, <<"number of JS filter invocation errors">>}
+]}.
 {[couchdb, legacy_checksums], [
     {type, counter},
     {desc, <<"number of legacy checksums found in couch_file instances">>}
 ]}.
+{[couchdb, btree, folds], [
+    {type, counter},
+    {desc, <<"number of couch btree kv fold callback invocations">>}
+]}.
+{[couchdb, btree, kp_node], [
+    {type, counter},
+    {desc, <<"number of couch btree kp_nodes read">>}
+]}.
+{[couchdb, btree, kv_node], [
+    {type, counter},
+    {desc, <<"number of couch btree kv_nodes read">>}
+]}.
+%% CSRT (couch_stats_resource_tracker) stats
+{[couchdb, csrt, delta_missing_t0], [
+    {type, counter},
+    {desc, <<"number of csrt contexts without a proper startime">>}
+]}.
 {[pread, exceed_eof], [
     {type, counter},
     {desc, <<"number of the attempts to read beyond end of db file">>}

src/couch/src/couch_btree.erl

@@ -472,6 +472,8 @@ reduce_tree_size(kp_node, NodeSize, [{_K, {_P, _Red, Sz}} | NodeList]) ->
 
 get_node(#btree{fd = Fd}, NodePos) ->
     {ok, {NodeType, NodeList}} = couch_file:pread_term(Fd, NodePos),
+    %% TODO: wire in csrt tracking
+    couch_stats:increment_counter([couchdb, btree, NodeType]),
     {NodeType, NodeList}.
 
 write_node(#btree{fd = Fd, compression = Comp} = Bt, NodeType, NodeList) ->
@@ -1163,6 +1165,7 @@ stream_kv_node2(Bt, Reds, PrevKVs, [{K, V} | RestKVs], InRange, Dir, Fun, Acc) -
         false ->
             {stop, {PrevKVs, Reds}, Acc};
         true ->
+            couch_stats:increment_counter([couchdb, btree, folds]),
             AssembledKV = assemble(Bt, K, V),
             case Fun(visit, AssembledKV, {PrevKVs, Reds}, Acc) of
                 {ok, Acc2} ->

src/couch/src/couch_db.erl

@@ -297,6 +297,7 @@ open_doc(Db, IdOrDocInfo) ->
     open_doc(Db, IdOrDocInfo, []).
 
 open_doc(Db, Id, Options) ->
+    %% TODO: wire in csrt tracking
     increment_stat(Db, [couchdb, database_reads]),
     case open_doc_int(Db, Id, Options) of
         {ok, #doc{deleted = true} = Doc} ->
@@ -1982,6 +1983,7 @@ increment_stat(#db{options = Options}, Stat, Count) when
 ->
     case lists:member(sys_db, Options) of
         true ->
+            %% TODO: we shouldn't leak resource usage just because it's a sys_db
             ok;
         false ->
             couch_stats:increment_counter(Stat, Count)

src/couch/src/couch_query_servers.erl

@@ -542,6 +542,8 @@ filter_docs(Req, Db, DDoc, FName, Docs) ->
         {ok, filter_docs_int(Db, DDoc, FName, JsonReq, JsonDocs)}
     catch
         throw:{os_process_error, {exit_status, 1}} ->
+            %% TODO: wire in csrt tracking
+            couch_stats:increment_counter([couchdb, query_server, js_filter_error]),
             %% batch used too much memory, retry sequentially.
             Fun = fun(JsonDoc) ->
                 filter_docs_int(Db, DDoc, FName, JsonReq, [JsonDoc])
@@ -550,6 +552,12 @@ filter_docs(Req, Db, DDoc, FName, Docs) ->
     end.
 
 filter_docs_int(Db, DDoc, FName, JsonReq, JsonDocs) ->
+    %% Count usage in _int version as this can be repeated for OS error
+    %% Pros & cons... might not have actually processed `length(JsonDocs)` docs
+    %% but it certainly undercounts if we count in `filter_docs/5` above
+    %% TODO: wire in csrt tracking
+    couch_stats:increment_counter([couchdb, query_server, js_filter]),
+    couch_stats:increment_counter([couchdb, query_server, js_filtered_docs], length(JsonDocs)),
     [true, Passes] = ddoc_prompt(
         Db,
         DDoc,

src/couch/src/couch_server.erl

@@ -97,6 +97,8 @@ sup_start_link(N) ->
     gen_server:start_link({local, couch_server(N)}, couch_server, [N], []).
 
 open(DbName, Options) ->
+    %% TODO: wire in csrt tracking
+    couch_stats:increment_counter([couchdb, couch_server, open]),
     try
         validate_open_or_create(DbName, Options),
         open_int(DbName, Options)

src/couch/src/couch_util.erl

@@ -46,6 +46,7 @@
 -export([verify_hash_names/2]).
 -export([get_config_hash_algorithms/0]).
 -export([remove_sensitive_data/1]).
+-export([clear_pdict/0, clear_pdict/1]).
 
 -include_lib("couch/include/couch_db.hrl").
 
@@ -870,3 +871,31 @@ remove_sensitive_data(KVList) ->
     KVList1 = lists:keyreplace(<<"password">>, 1, KVList, {<<"password">>, <<"****">>}),
     % some KVList entries are atoms, so test fo this too
     lists:keyreplace(password, 1, KVList1, {password, <<"****">>}).
+
+-spec clear_pdict() -> ok.
+clear_pdict() ->
+    clear_pdict(erlang:get()).
+
+%% Exclude mochiweb markers, otherwise just use erlang:erase/0
+-spec clear_pdict(list()) -> ok.
+clear_pdict([]) ->
+    ok;
+clear_pdict([{mochiweb_request_body, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_body_length, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_cookie, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_force_close, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_path, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_post, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_qs, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{mochiweb_request_recv, _V} | Rest]) ->
+    clear_pdict(Rest);
+clear_pdict([{Key, _V} | Rest]) ->
+    erlang:erase(Key),
+    clear_pdict(Rest).

src/couch_stats/src/couch_stats.app.src

@@ -13,8 +13,12 @@
 {application, couch_stats, [
     {description, "Simple statistics collection"},
     {vsn, git},
-    {registered, [couch_stats_aggregator, couch_stats_process_tracker]},
-    {applications, [kernel, stdlib]},
+    {registered, [
+        couch_stats_aggregator,
+        couch_stats_process_tracker,
+        couch_stats_resource_tracker
+    ]},
+    {applications, [kernel, stdlib, couch_log]},
     {mod, {couch_stats_app, []}},
     {env, []}
 ]}.