umgeher/leveled
0
Fork 0
Code Issues Pull requests Releases Activity Actions

Switch to using bloom at penciller

Browse source 
Previouslythe tinybloom was used within the SST file as an extra check to remove false fetches.

However the SST already has a low FPR check in the slot_index.  If the newebloom was used (which is no longer per slot, but per sst), this can be shared with the penciller and then the penciller could use it and avoid the message pass.

the message pass may be blocked by a 2i query or a slot fetch request for a merge.  So this should make performance within the Penciller snappier.

This is as a result of taking sst_timings within a volume test - where there was an average of + 100microsecs for each level that was dropped down.  Given the bloom/slot checks were < 20 microsecs - there seems to be some further delay.

The bloom is a binary of > 64 bytes - so passing it around should not require a copy.
This commit is contained in:
Martin Sumner 2017-11-28 01:19:30 +00:00
parent 467ad50cd1
commit c2f19d8825
8 changed files with 367 additions and 572 deletions
Download patch file Download diff file Expand all files Collapse all files

57
src/leveled_penciller.erl
View file

@ -181,7 +181,7 @@
pcl_checksequencenumber/3,
pcl_workforclerk/1,
pcl_manifestchange/2,
pcl_confirml0complete/4,
pcl_confirml0complete/5,
pcl_confirmdelete/3,
pcl_close/1,
pcl_doom/1,
@ -439,14 +439,14 @@ pcl_workforclerk(Pid) ->
pcl_manifestchange(Pid, Manifest) ->
gen_server:cast(Pid, {manifest_change, Manifest}).
-spec pcl_confirml0complete(pid(), string(), tuple(), tuple()) -> ok.
-spec pcl_confirml0complete(pid(), string(), tuple(), tuple(), binary()) -> ok.
%% @doc
%% Allows a SST writer that has written a L0 file to confirm that the file
%% is now complete, so the filename and key ranges can be added to the
%% manifest and the file can be used in place of the in-memory levelzero
%% cache.
pcl_confirml0complete(Pid, FN, StartKey, EndKey) ->
gen_server:cast(Pid, {levelzero_complete, FN, StartKey, EndKey}).
pcl_confirml0complete(Pid, FN, StartKey, EndKey, Bloom) ->
gen_server:cast(Pid, {levelzero_complete, FN, StartKey, EndKey, Bloom}).
-spec pcl_confirmdelete(pid(), string(), pid()) -> ok.
%% @doc
@ -759,17 +759,18 @@ handle_cast({confirm_delete, Filename, FilePid}, State=#state{is_snapshot=Snap})
% from the Clerk
{noreply, State}
end;
handle_cast({levelzero_complete, FN, StartKey, EndKey}, State) ->
handle_cast({levelzero_complete, FN, StartKey, EndKey, Bloom}, State) ->
leveled_log:log("P0029", []),
ManEntry = #manifest_entry{start_key=StartKey,
end_key=EndKey,
owner=State#state.levelzero_constructor,
filename=FN},
filename=FN,
bloom=Bloom},
ManifestSQN = leveled_pmanifest:get_manifest_sqn(State#state.manifest) + 1,
UpdMan = leveled_pmanifest:insert_manifest_entry(State#state.manifest,
ManifestSQN,
0,
ManEntry),
ManifestSQN,
0,
ManEntry),
% Prompt clerk to ask about work - do this for every L0 roll
UpdIndex = leveled_pmem:clear_index(State#state.levelzero_index),
ok = leveled_pclerk:clerk_prompt(State#state.clerk),
@ -837,7 +838,7 @@ terminate(Reason, State) ->
L0_Left = State#state.levelzero_size > 0,
case {State#state.levelzero_pending, L0_Present, L0_Left} of
{false, false, true} ->
L0Pid = roll_memory(State, true),
{L0Pid, _L0Bloom} = roll_memory(State, true),
ok = leveled_sst:sst_close(L0Pid);
StatusTuple ->
leveled_log:log("P0010", [StatusTuple])
@ -911,11 +912,9 @@ start_from_file(PCLopts) ->
Manifest0 = leveled_pmanifest:open_manifest(RootPath),
OpenFun =
fun(FN) ->
{ok,
Pid,
{_FK, _LK}} =
leveled_sst:sst_open(sst_rootpath(RootPath), FN),
Pid
{ok, Pid, {_FK, _LK}, Bloom} =
leveled_sst:sst_open(sst_rootpath(RootPath), FN),
{Pid, Bloom}
end,
SQNFun = fun leveled_sst:sst_getmaxsequencenumber/1,
{MaxSQN, Manifest1, FileList} =
@ -930,12 +929,13 @@ start_from_file(PCLopts) ->
true ->
leveled_log:log("P0015", [L0FN]),
L0Open = leveled_sst:sst_open(sst_rootpath(RootPath), L0FN),
{ok, L0Pid, {L0StartKey, L0EndKey}} = L0Open,
{ok, L0Pid, {L0StartKey, L0EndKey}, Bloom} = L0Open,
L0SQN = leveled_sst:sst_getmaxsequencenumber(L0Pid),
L0Entry = #manifest_entry{start_key = L0StartKey,
end_key = L0EndKey,
filename = L0FN,
owner = L0Pid},
owner = L0Pid,
bloom = Bloom},
Manifest2 = leveled_pmanifest:insert_manifest_entry(Manifest1,
ManSQN + 1,
0,
@ -1025,7 +1025,7 @@ update_levelzero(L0Size, {PushedTree, PushedIdx, MinSQN, MaxSQN},
JitterCheck = RandomFactor or CacheMuchTooBig,
case {CacheTooBig, L0Free, JitterCheck, NoPendingManifestChange} of
{true, true, true, true} ->
L0Constructor = roll_memory(UpdState, false),
{L0Constructor, none} = roll_memory(UpdState, false),
leveled_log:log_timer("P0031", [true, true], SW),
UpdState#state{levelzero_pending=true,
levelzero_constructor=L0Constructor};
@ -1063,7 +1063,7 @@ roll_memory(State, false) ->
State#state.ledger_sqn,
State#state.compression_method),
{ok, Constructor, _} = R,
Constructor;
{Constructor, none};
roll_memory(State, true) ->
ManSQN = leveled_pmanifest:get_manifest_sqn(State#state.manifest) + 1,
RootPath = sst_rootpath(State#state.root_path),
@ -1077,8 +1077,8 @@ roll_memory(State, true) ->
KVList,
State#state.ledger_sqn,
State#state.compression_method),
{ok, Constructor, _} = R,
Constructor.
{ok, Constructor, _, Bloom} = R,
{Constructor, Bloom}.
timed_fetch_mem(Key, Hash, Manifest, L0Cache, L0Index, Timings) ->
SW = os:timestamp(),
@ -1107,11 +1107,16 @@ fetch(Key, Hash, Manifest, Level, FetchFun) ->
false ->
fetch(Key, Hash, Manifest, Level + 1, FetchFun);
FP ->
case FetchFun(FP, Key, Hash, Level) of
not_present ->
fetch(Key, Hash, Manifest, Level + 1, FetchFun);
ObjectFound ->
{ObjectFound, Level}
case leveled_pmanifest:check_bloom(Manifest, FP, Hash) of
true ->
case FetchFun(FP, Key, Hash, Level) of
not_present ->
fetch(Key, Hash, Manifest, Level + 1, FetchFun);
ObjectFound ->
{ObjectFound, Level}
end;
false ->
fetch(Key, Hash, Manifest, Level + 1, FetchFun)
end
end.