Fixed matchspec miss and added retry logic w/ ets
In prior commit, missed switch of matchspec to work
with deletes, fixed here.
Added retry logic for race conditions around lb and
conn both trying to update same record at the same time.
If more than max is experienced, just let it go, things
will probably be ok.
diff --git a/src/ibrowse_lb.erl b/src/ibrowse_lb.erl
index 3d487d4..eabba3a 100644
--- a/src/ibrowse_lb.erl
+++ b/src/ibrowse_lb.erl
@@ -38,8 +38,9 @@
proc_state}).
-define(PIPELINE_MAX, 99999).
+-define(MAX_RETRIES, 3).
-define(KEY_MATCHSPEC_BY_PID(Pid), [{{{'_', '_', Pid}, '_'}, [], ['$_']}]).
--define(KEY_MATCHSPEC(Key), [{{Key, '_'}, [], ['$_']}]).
+-define(KEY_MATCHSPEC_BY_PID_FOR_DELETE(Pid), [{{{'_', '_', Pid}, '_'}, [], [true]}]).
-define(KEY_MATCHSPEC_FOR_DELETE(Key), [{{Key, '_'}, [], [true]}]).
-include("ibrowse.hrl").
@@ -77,22 +78,10 @@
report_connection_down(Tid) ->
%% Don't cascade errors since Tid is really managed by other process
- catch ets:select_delete(Tid, ?KEY_MATCHSPEC_BY_PID(self())).
+ catch ets:select_delete(Tid, ?KEY_MATCHSPEC_BY_PID_FOR_DELETE(self())).
report_request_complete(Tid) ->
- %% Don't cascade errors since Tid is really managed by other process
- catch case ets:select(Tid, ?KEY_MATCHSPEC_BY_PID(self())) of
- [MatchKey] ->
- case ets:select_delete(Tid, ?KEY_MATCHSPEC_FOR_DELETE(MatchKey)) of
- 1 ->
- ets:insert(Tid, {decremented(MatchKey), undefined}),
- true;
- _ ->
- false
- end;
- _ ->
- false
- end.
+ report_request_complete(Tid, ?MAX_RETRIES).
%%====================================================================
%% Server functions
@@ -223,13 +212,18 @@
%%% Internal functions
%%--------------------------------------------------------------------
find_best_connection(Tid, Max_pipeline_size) ->
+ find_best_connection(Tid, Max_pipeline_size, ?MAX_RETRIES).
+
+find_best_connection(_Tid, _Max_pipeline_size, 0) ->
+ {error, retry_later};
+find_best_connection(Tid, Max_pipeline_size, RemainingRetries) ->
case ets:first(Tid) of
{Size, _Timestamp, Pid} = Key when Size < Max_pipeline_size ->
case record_request_for_connection(Tid, Key) of
true ->
{ok, Pid};
false ->
- find_best_connection(Tid, Max_pipeline_size)
+ find_best_connection(Tid, Max_pipeline_size, RemainingRetries - 1)
end;
_ ->
{error, retry_later}
@@ -257,6 +251,24 @@
false
end.
+report_request_complete(_Tid, 0) ->
+ false;
+report_request_complete(Tid, RemainingRetries) ->
+ %% Don't cascade errors since Tid is really managed by other process
+ catch case ets:select(Tid, ?KEY_MATCHSPEC_BY_PID(self())) of
+ [MatchKey] ->
+ case ets:select_delete(Tid, ?KEY_MATCHSPEC_FOR_DELETE(MatchKey)) of
+ 1 ->
+ ets:insert(Tid, {decremented(MatchKey), undefined}),
+ true;
+ _ ->
+ report_request_complete(Tid, RemainingRetries - 1)
+ end;
+ _ ->
+ false
+ end.
+
+
new_key(Pid) ->
{1, os:timestamp(), Pid}.
