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vatamane pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/couchdb.git
The following commit(s) were added to refs/heads/main by this push:
new 275c06b9d Cleanup off-heap/priority flags
275c06b9d is described below
commit 275c06b9d71781531f9d8f903a4cb9f542f85c8a
Author: Nick Vatamaniuc <[email protected]>
AuthorDate: Tue Nov 11 00:05:37 2025 -0500
Cleanup off-heap/priority flags
Make all processes run at normal priority.
In production observed cases which had a very couch cfile cleaner queue
(500k
messages). That's likely because couch_servers are running at high priority
on
every scheduler, opening/closing files, and the single couch_cfile janitor
process runs at normal priority, and can't keep up with cleanup. Since
there is
no super-high-priority to set the janitor to, let's just set them all to
normal. Besides, we've had issue with high priority proceses before
triggering
various OTP bugs and had to revert at least once before:
https://github.com/erlang/otp/issues/4078.
Also, in the same vein, we never had to disable the off_heap flag in 7 years
since it's been made configurable, so let's remove the extra config fluff
and
always set it unconditionally.
---
rel/overlay/etc/default.ini | 16 ----------------
src/couch/src/couch_server.erl | 3 +--
src/couch/src/couch_util.erl | 25 -------------------------
src/couch_event/src/couch_event_server.erl | 2 +-
src/couch_log/src/couch_log_server.erl | 2 +-
src/ddoc_cache/src/ddoc_cache_lru.erl | 2 +-
src/dreyfus/src/dreyfus_index_manager.erl | 2 +-
src/mem3/src/mem3_shards.erl | 2 +-
src/nouveau/src/nouveau_index_manager.erl | 2 +-
src/rexi/src/rexi_server.erl | 2 +-
10 files changed, 8 insertions(+), 50 deletions(-)
diff --git a/rel/overlay/etc/default.ini b/rel/overlay/etc/default.ini
index 31fc69e15..66747fc88 100644
--- a/rel/overlay/etc/default.ini
+++ b/rel/overlay/etc/default.ini
@@ -1233,19 +1233,3 @@ url = {{nouveau_url}}
; from the _first_ authentication failure.
; note: changing this setting requires a couchdb restart.
;max_lifetime = 300000
-
-[off_heap_mqd]
-; Set Erlang process_flag(message_queue_data, off_heap) for the respective
-; module if the setting is true. Off-heap messages do not participate in the
-; process garbage collection. If processes expect to get a large message queue,
-; it usually make sense to set to true, as otherwise GC may take too long.
-; However in some cases that could affect latency as it takes an extra copy
-; step to copy them into the process heap.
-;rexi_server = true
-;couch_log_server = true
-;couch_server = true
-;couch_event_server = true
-;ddoc_cache_lru = true
-;mem3_shards = true
-;nouveau_index_manager = true
-;dreyfus_index_manager = true
diff --git a/src/couch/src/couch_server.erl b/src/couch/src/couch_server.erl
index 246cdd1cb..4b66993f8 100644
--- a/src/couch/src/couch_server.erl
+++ b/src/couch/src/couch_server.erl
@@ -279,8 +279,7 @@ close_db_if_idle(DbName) ->
end.
init([N]) ->
- couch_util:set_mqd_off_heap(?MODULE),
- couch_util:set_process_priority(?MODULE, high),
+ erlang:process_flag(message_queue_data, off_heap),
% Mark pluggable storage engines as a supported feature
config:enable_feature('pluggable-storage-engines'),
diff --git a/src/couch/src/couch_util.erl b/src/couch/src/couch_util.erl
index e92caab93..d93aaebd6 100644
--- a/src/couch/src/couch_util.erl
+++ b/src/couch/src/couch_util.erl
@@ -39,8 +39,6 @@
-export([unique_monotonic_integer/0]).
-export([check_config_blacklist/1]).
-export([check_md5/2]).
--export([set_mqd_off_heap/1]).
--export([set_process_priority/2]).
-export([hmac/3]).
-export([version_to_binary/1]).
-export([verify_hash_names/2]).
@@ -685,29 +683,6 @@ check_md5(_NewSig, <<>>) -> ok;
check_md5(Sig, Sig) -> ok;
check_md5(_, _) -> throw(md5_mismatch).
-set_mqd_off_heap(Module) ->
- case config:get_boolean("off_heap_mqd", atom_to_list(Module), true) of
- true ->
- try
- erlang:process_flag(message_queue_data, off_heap),
- ok
- catch
- error:badarg ->
- ok
- end;
- false ->
- ok
- end.
-
-set_process_priority(Module, Level) ->
- case config:get_boolean("process_priority", atom_to_list(Module), false) of
- true ->
- process_flag(priority, Level),
- ok;
- false ->
- ok
- end.
-
ensure_loaded(Module) when is_atom(Module) ->
case code:ensure_loaded(Module) of
{module, Module} ->
diff --git a/src/couch_event/src/couch_event_server.erl
b/src/couch_event/src/couch_event_server.erl
index f14730688..94ab0d4a8 100644
--- a/src/couch_event/src/couch_event_server.erl
+++ b/src/couch_event/src/couch_event_server.erl
@@ -33,7 +33,7 @@ start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, nil, []).
init(_) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
{ok, #st{
by_pid = #{},
by_dbname = #{}
diff --git a/src/couch_log/src/couch_log_server.erl
b/src/couch_log/src/couch_log_server.erl
index 0191b05ee..ed26a5e27 100644
--- a/src/couch_log/src/couch_log_server.erl
+++ b/src/couch_log/src/couch_log_server.erl
@@ -47,7 +47,7 @@ log(Entry) ->
?SEND(Entry).
init(_) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
process_flag(trap_exit, true),
{ok, #st{
writer = couch_log_writer:init()
diff --git a/src/ddoc_cache/src/ddoc_cache_lru.erl
b/src/ddoc_cache/src/ddoc_cache_lru.erl
index b3ed6b83f..be0c98321 100644
--- a/src/ddoc_cache/src/ddoc_cache_lru.erl
+++ b/src/ddoc_cache/src/ddoc_cache_lru.erl
@@ -77,7 +77,7 @@ refresh(DbName, DDocIds) ->
gen_server:cast(?MODULE, {refresh, DbName, DDocIds}).
init(_) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
process_flag(trap_exit, true),
BaseOpts = [public, named_table],
CacheOpts =
diff --git a/src/dreyfus/src/dreyfus_index_manager.erl
b/src/dreyfus/src/dreyfus_index_manager.erl
index 6b7649d1b..a54db5e15 100644
--- a/src/dreyfus/src/dreyfus_index_manager.erl
+++ b/src/dreyfus/src/dreyfus_index_manager.erl
@@ -46,7 +46,7 @@ get_disk_size(DbName, #index{sig = Sig}) ->
% gen_server functions.
init([]) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
ets:new(?BY_SIG, [set, private, named_table]),
ets:new(?BY_PID, [set, private, named_table]),
couch_event:link_listener(?MODULE, handle_db_event, nil, [all_dbs]),
diff --git a/src/mem3/src/mem3_shards.erl b/src/mem3/src/mem3_shards.erl
index ba31ffbeb..3ebdcfe55 100644
--- a/src/mem3/src/mem3_shards.erl
+++ b/src/mem3/src/mem3_shards.erl
@@ -230,7 +230,7 @@ handle_config_terminate(_Server, _Reason, _State) ->
erlang:send_after(?RELISTEN_DELAY, whereis(?MODULE),
restart_config_listener).
init([]) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
CacheEtsOpts = [public, named_table, {read_concurrency, true},
{write_concurrency, auto}],
ets:new(?OPTS, CacheEtsOpts),
ets:new(?SHARDS, [bag, {keypos, #shard.dbname}] ++ CacheEtsOpts),
diff --git a/src/nouveau/src/nouveau_index_manager.erl
b/src/nouveau/src/nouveau_index_manager.erl
index 45f7a1e8d..44ee17a4d 100644
--- a/src/nouveau/src/nouveau_index_manager.erl
+++ b/src/nouveau/src/nouveau_index_manager.erl
@@ -53,7 +53,7 @@ update_index(#index{} = Index) ->
end.
init(_) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
ets:new(?BY_DBSIG, [set, named_table]),
ets:new(?BY_REF, [set, named_table]),
couch_event:link_listener(?MODULE, handle_db_event, nil, [all_dbs]),
diff --git a/src/rexi/src/rexi_server.erl b/src/rexi/src/rexi_server.erl
index 9028616bd..dc2287154 100644
--- a/src/rexi/src/rexi_server.erl
+++ b/src/rexi/src/rexi_server.erl
@@ -43,7 +43,7 @@ start_link(ServerId) ->
gen_server:start_link({local, ServerId}, ?MODULE, [], []).
init([]) ->
- couch_util:set_mqd_off_heap(?MODULE),
+ erlang:process_flag(message_queue_data, off_heap),
{ok, #st{}}.
handle_call(get_errors, _From, #st{errors = Errors} = St) ->
