119 lines
3.6 KiB
Ruby
119 lines
3.6 KiB
Ruby
# THIS FILE IS TO BE EXTRACTED FROM DISCOURSE IT IS LICENSED UNDER THE MIT LICENSE
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#
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# The MIT License (MIT)
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#
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# Copyright (c) 2013 Discourse
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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# Hook into unicorn, unicorn middleware, not rack middleware
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#
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# Since we need no knowledge about the request we can simply
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# hook unicorn
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module Middleware::UnicornOobgc
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MIN_REQUESTS_PER_OOBGC = 3
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# TUNE ME, for Discourse this number is good
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MIN_FREE_SLOTS = 50_000
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def verbose(msg=nil)
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@verbose ||= ENV["OOBGC_VERBOSE"] == "1" ? :true : :false
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if @verbose == :true
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if(msg)
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puts msg
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end
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true
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end
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end
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def self.init
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# hook up HttpServer intercept
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ObjectSpace.each_object(Unicorn::HttpServer) do |s|
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s.extend(self)
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end
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rescue
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puts "Attempted to patch Unicorn but it is not loaded"
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end
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# the closer this is to the GC run the more accurate it is
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def estimate_live_num_at_gc(stat)
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stat[:heap_live_num] + stat[:heap_free_num]
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end
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def process_client(client)
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stat = GC.stat
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@num_requests ||= 0
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@num_requests += 1
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gc_count = stat[:count]
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live_num = stat[:heap_live_num]
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@expect_gc_at ||= estimate_live_num_at_gc(stat)
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super(client) # Unicorn::HttpServer#process_client
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# at this point client is serviced
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stat = GC.stat
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new_gc_count = stat[:count]
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new_live_num = stat[:heap_live_num]
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# no GC happened during the request
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if new_gc_count == gc_count
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delta = new_live_num - live_num
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@max_delta ||= delta
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if delta > @max_delta
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new_delta = (delta * 1.5).to_i
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@max_delta = [new_delta, delta].min
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else
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# this may seem like a very tiny decay rate, but some apps using caching
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# can really mess stuff up, if our delta is too low the algorithm fails
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new_delta = (delta * 0.995).to_i
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@max_delta = [new_delta, delta].max
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end
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if @max_delta < MIN_FREE_SLOTS
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@max_delta = MIN_FREE_SLOTS
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end
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if @num_requests > MIN_REQUESTS_PER_OOBGC && @max_delta * 2 + new_live_num > @expect_gc_at
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t = Time.now
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GC.start
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stat = GC.stat
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@expect_gc_at = estimate_live_num_at_gc(stat)
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verbose "OobGC hit pid: #{Process.pid} req: #{@num_requests} max delta: #{@max_delta} expect at: #{@expect_gc_at} #{((Time.now - t) * 1000).to_i}ms saved"
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@num_requests = 0
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end
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else
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verbose "OobGC miss pid: #{Process.pid} reqs: #{@num_requests} max delta: #{@max_delta}"
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@num_requests = 0
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@expect_gc_at = estimate_live_num_at_gc(stat)
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end
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end
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end
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