Revert "Parallelize template rendering"

This reverts commit 1ad71592ad.

Since it had no limit on the number on concurrent processes it OOM killed
instances while rendering hellthreads. When I tried introducing a
concurrency limit with Task.async_stream/manual folds it lead to about 3 times
worse performance on threads larger than 1000 activities (we are talking
30s vs 1.2 minutes), I think this is not worth the about 1.5 times
performance increase on smaller threads when using it.
This commit is contained in:
rinpatch 2019-09-10 22:01:45 +03:00
parent edbaf78176
commit 43f02dfe38
3 changed files with 12 additions and 48 deletions

View file

@ -37,37 +37,17 @@ def run(["render_timeline", nickname]) do
|> Map.put("blocking_user", user)
|> Map.put("muting_user", user)
|> Map.put("user", user)
|> Map.put("limit", 80)
|> Pleroma.Web.ActivityPub.ActivityPub.fetch_public_activities()
|> Enum.reverse()
inputs = %{
"One activity" => Enum.take_random(activities, 1),
"Ten activities" => Enum.take_random(activities, 10),
"Twenty activities" => Enum.take_random(activities, 20),
"Forty activities" => Enum.take_random(activities, 40),
"Eighty activities" => Enum.take_random(activities, 80)
}
Benchee.run(
%{
"Parallel rendering" => fn activities ->
Pleroma.Web.MastodonAPI.StatusView.render("index.json", %{
activities: activities,
for: user,
as: :activity
})
end,
"Standart rendering" => fn activities ->
Pleroma.Web.MastodonAPI.StatusView.render("index.json", %{
activities: activities,
for: user,
as: :activity,
parallel: false
})
end
},
inputs: inputs
)
Benchee.run(%{
"render_timeline" => fn ->
Pleroma.Web.MastodonAPI.StatusView.render("index.json", %{
activities: activities,
for: user,
as: :activity
})
end
})
end
end

View file

@ -73,14 +73,12 @@ defp reblogged?(activity, user) do
def render("index.json", opts) do
replied_to_activities = get_replied_to_activities(opts.activities)
parallel = unless is_nil(opts[:parallel]), do: opts[:parallel], else: true
opts.activities
|> safe_render_many(
StatusView,
"status.json",
Map.put(opts, :replied_to_activities, replied_to_activities),
parallel
Map.put(opts, :replied_to_activities, replied_to_activities)
)
end

View file

@ -66,23 +66,9 @@ def safe_render(view, template, assigns \\ %{}) do
end
@doc """
Same as `render_many/4` but wrapped in rescue block and parallelized (unless disabled by passing false as a fifth argument).
Same as `render_many/4` but wrapped in rescue block.
"""
def safe_render_many(collection, view, template, assigns \\ %{}, parallel \\ true)
def safe_render_many(collection, view, template, assigns, true) do
Enum.map(collection, fn resource ->
Task.async(fn ->
as = Map.get(assigns, :as) || view.__resource__
assigns = Map.put(assigns, as, resource)
safe_render(view, template, assigns)
end)
end)
|> Enum.map(&Task.await(&1, :infinity))
|> Enum.filter(& &1)
end
def safe_render_many(collection, view, template, assigns, false) do
def safe_render_many(collection, view, template, assigns \\ %{}) do
Enum.map(collection, fn resource ->
as = Map.get(assigns, :as) || view.__resource__
assigns = Map.put(assigns, as, resource)