Commit cb286fde authored by Michael Loftis's avatar Michael Loftis 🦀

Improves RetryQueue behavior

reduces to one single timer firing once a second
switches to a parallel worker model
parent f5d7b000
......@@ -7,20 +7,34 @@ defmodule Pleroma.Web.Federator.RetryQueue do
require Logger
# initial timeout, 5 min
@initial_timeout 30_000
# seconds
@initial_timeout 30
@max_retries 5
@max_jobs 20
def init(args) do
{:ok, args}
queue_table = :ets.new(:pleroma_retry_queue, [:bag, :protected])
{:ok, %{args | queue_table: queue_table, running_jobs: :sets.new()}}
end
def start_link() do
enabled = Pleroma.Config.get([:retry_queue, :enabled], false)
enabled =
if Mix.env() == :test, do: true, else: Pleroma.Config.get([:retry_queue, :enabled], false)
if enabled do
Logger.info("Starting retry queue")
GenServer.start_link(__MODULE__, %{delivered: 0, dropped: 0}, name: __MODULE__)
linkres =
GenServer.start_link(
__MODULE__,
%{delivered: 0, dropped: 0, queue_table: nil, running_jobs: nil},
name: __MODULE__
)
maybe_kickoff_timer()
linkres
else
Logger.info("Retry queue disabled")
:ignore
......@@ -31,6 +45,14 @@ def enqueue(data, transport, retries \\ 0) do
GenServer.cast(__MODULE__, {:maybe_enqueue, data, transport, retries + 1})
end
def get_stats() do
GenServer.call(__MODULE__, :get_stats)
end
def reset_stats() do
GenServer.call(__MODULE__, :reset_stats)
end
def get_retry_params(retries) do
if retries > @max_retries do
{:drop, "Max retries reached"}
......@@ -39,16 +61,118 @@ def get_retry_params(retries) do
end
end
def handle_cast({:maybe_enqueue, data, transport, retries}, %{dropped: drop_count} = state) do
def get_retry_timer_interval() do
Pleroma.Config.get([:retry_queue, :interval], 1000)
end
defp ets_count_expires(table, current_time) do
:ets.select_count(
table,
[
{
{:"$1", :"$2"},
[{:"=<", :"$1", {:const, current_time}}],
[true]
}
]
)
end
defp ets_pop_n_expired(table, current_time, desired) do
{popped, _continuation} =
:ets.select(
table,
[
{
{:"$1", :"$2"},
[{:"=<", :"$1", {:const, current_time}}],
[:"$_"]
}
],
desired
)
popped
|> List.foldl(true, fn e, acc ->
:ets.delete_object(table, e)
acc
end)
popped
end
def maybe_start_job(running_jobs, queue_table) do
# we don't want to hit the ets or the DateTime more times than we have to
# could optimize slightly further by not using the count, and instead grabbing
# up to N objects early...
current_time = DateTime.to_unix(DateTime.utc_now())
n_running_jobs = :sets.size(running_jobs)
if n_running_jobs < @max_jobs do
n_ready_jobs = ets_count_expires(queue_table, current_time)
if n_ready_jobs > 0 do
# figure out how many we could start
available_job_slots = @max_jobs - n_running_jobs
start_n_jobs(running_jobs, queue_table, current_time, available_job_slots)
else
running_jobs
end
else
running_jobs
end
end
defp start_n_jobs(running_jobs, _queue_table, _current_time, 0) do
running_jobs
end
defp start_n_jobs(running_jobs, queue_table, current_time, available_job_slots)
when available_job_slots > 0 do
candidates = ets_pop_n_expired(queue_table, current_time, available_job_slots)
candidates
|> List.foldl(running_jobs, fn {_, e}, rj ->
{:ok, pid} = Task.start(fn -> worker(e) end)
mref = Process.monitor(pid)
:sets.add_element(mref, rj)
end)
end
def worker({:send, data, transport, retries}) do
case transport.publish_one(data) do
{:ok, _} ->
GenServer.cast(__MODULE__, :inc_delivered)
:delivered
{:error, _reason} ->
enqueue(data, transport, retries)
:retry
end
end
def handle_call(:get_stats, _from, %{delivered: delivery_count, dropped: drop_count} = state) do
{:reply, %{delivered: delivery_count, dropped: drop_count}, state}
end
def handle_call(:reset_stats, _from, %{delivered: delivery_count, dropped: drop_count} = state) do
{:reply, %{delivered: delivery_count, dropped: drop_count},
%{state | delivered: 0, dropped: 0}}
end
def handle_cast(:reset_stats, state) do
{:noreply, %{state | delivered: 0, dropped: 0}}
end
def handle_cast(
{:maybe_enqueue, data, transport, retries},
%{dropped: drop_count, queue_table: queue_table, running_jobs: running_jobs} = state
) do
case get_retry_params(retries) do
{:retry, timeout} ->
Process.send_after(
__MODULE__,
{:send, data, transport, retries},
timeout
)
{:noreply, state}
:ets.insert(queue_table, {timeout, {:send, data, transport, retries}})
running_jobs = maybe_start_job(running_jobs, queue_table)
{:noreply, %{state | running_jobs: running_jobs}}
{:drop, message} ->
Logger.debug(message)
......@@ -56,6 +180,20 @@ def handle_cast({:maybe_enqueue, data, transport, retries}, %{dropped: drop_coun
end
end
def handle_cast(:kickoff_timer, state) do
retry_interval = get_retry_timer_interval()
Process.send_after(__MODULE__, :retry_timer_run, retry_interval)
{:noreply, state}
end
def handle_cast(:inc_delivered, %{delivered: delivery_count} = state) do
{:noreply, %{state | delivered: delivery_count + 1}}
end
def handle_cast(:inc_dropped, %{dropped: drop_count} = state) do
{:noreply, %{state | dropped: drop_count + 1}}
end
def handle_info({:send, data, transport, retries}, %{delivered: delivery_count} = state) do
case transport.publish_one(data) do
{:ok, _} ->
......@@ -67,12 +205,39 @@ def handle_info({:send, data, transport, retries}, %{delivered: delivery_count}
end
end
def handle_info(
:retry_timer_run,
%{queue_table: queue_table, running_jobs: running_jobs} = state
) do
maybe_kickoff_timer()
running_jobs = maybe_start_job(running_jobs, queue_table)
{:noreply, %{state | running_jobs: running_jobs}}
end
def handle_info({:DOWN, ref, :process, _pid, _reason}, state) do
%{running_jobs: running_jobs, queue_table: queue_table} = state
running_jobs = :sets.del_element(ref, running_jobs)
running_jobs = maybe_start_job(running_jobs, queue_table)
{:noreply, %{state | running_jobs: running_jobs}}
end
def handle_info(unknown, state) do
Logger.debug("RetryQueue: don't know what to do with #{inspect(unknown)}, ignoring")
{:noreply, state}
end
defp growth_function(retries) do
round(@initial_timeout * :math.pow(retries, 3))
if Mix.env() == :test do
defp growth_function(_retries) do
_shutit = @initial_timeout
DateTime.to_unix(DateTime.utc_now()) - 1
end
else
defp growth_function(retries) do
round(@initial_timeout * :math.pow(retries, 3)) + DateTime.to_unix(DateTime.utc_now())
end
end
defp maybe_kickoff_timer() do
GenServer.cast(__MODULE__, :kickoff_timer)
end
end
......@@ -3,7 +3,8 @@
# SPDX-License-Identifier: AGPL-3.0-only
defmodule MockActivityPub do
def publish_one(ret) do
def publish_one({ret, waiter}) do
send(waiter, :complete)
{ret, "success"}
end
end
......@@ -15,21 +16,33 @@ defmodule Pleroma.Web.Federator.RetryQueueTest do
@small_retry_count 0
@hopeless_retry_count 10
setup do
RetryQueue.reset_stats()
end
test "RetryQueue responds to stats request" do
assert %{delivered: 0, dropped: 0} == RetryQueue.get_stats()
end
test "failed posts are retried" do
{:retry, _timeout} = RetryQueue.get_retry_params(@small_retry_count)
assert {:noreply, %{delivered: 1}} ==
RetryQueue.handle_info({:send, :ok, MockActivityPub, @small_retry_count}, %{
delivered: 0
})
wait_task =
Task.async(fn ->
receive do
:complete -> :ok
end
end)
RetryQueue.enqueue({:ok, wait_task.pid}, MockActivityPub, @small_retry_count)
Task.await(wait_task)
assert %{delivered: 1, dropped: 0} == RetryQueue.get_stats()
end
test "posts that have been tried too many times are dropped" do
{:drop, _timeout} = RetryQueue.get_retry_params(@hopeless_retry_count)
assert {:noreply, %{dropped: 1}} ==
RetryQueue.handle_cast({:maybe_enqueue, %{}, nil, @hopeless_retry_count}, %{
dropped: 0
})
RetryQueue.enqueue({:ok, nil}, MockActivityPub, @hopeless_retry_count)
assert %{delivered: 0, dropped: 1} == RetryQueue.get_stats()
end
end
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