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The following commit(s) were added to refs/heads/master by this push:
new ba11e7f feat: ewma use p2c to improve performance (#3300)
ba11e7f is described below
commit ba11e7fa0a005a6a60cf9360bcbb83c22aa25028
Author: 大可 <hnlq.s...@gmail.com>
AuthorDate: Fri Jan 29 17:17:22 2021 +0800
feat: ewma use p2c to improve performance (#3300)
---
apisix/balancer/ewma.lua | 158 +++++++++++++++++++++++++++++---------------
t/node/ewma.t | 166 ++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 270 insertions(+), 54 deletions(-)
diff --git a/apisix/balancer/ewma.lua b/apisix/balancer/ewma.lua
index b66b07a..e1b2762 100644
--- a/apisix/balancer/ewma.lua
+++ b/apisix/balancer/ewma.lua
@@ -3,28 +3,50 @@
-- Inspiration drawn from:
--
https://github.com/twitter/finagle/blob/1bc837c4feafc0096e43c0e98516a8e1c50c4421
--
/finagle-core/src/main/scala/com/twitter/finagle/loadbalancer/PeakEwma.scala
-
local core = require("apisix.core")
+local resty_lock = require("resty.lock")
+
+local nkeys = core.table.nkeys
+local table_insert = core.table.insert
local ngx = ngx
local ngx_shared = ngx.shared
local ngx_now = ngx.now
local math = math
local pairs = pairs
+local ipairs = ipairs
local next = next
+local error = error
-local _M = {}
local DECAY_TIME = 10 -- this value is in seconds
+local LOCK_KEY = ":ewma_key"
local shm_ewma = ngx_shared.balancer_ewma
-local shm_last_touched_at= ngx_shared.balancer_ewma_last_touched_at
+local shm_last_touched_at = ngx_shared.balancer_ewma_last_touched_at
+
+local lrucache_addr = core.lrucache.new({ttl = 300, count = 1024})
+local lrucache_trans_format = core.lrucache.new({ttl = 300, count = 256})
+
+local ewma_lock, ewma_lock_err = resty_lock:new("balancer_ewma_locks",
{timeout = 0, exptime = 0.1})
-local lrucache_addr = core.lrucache.new({
- ttl = 300, count = 1024
-})
-local lrucache_trans_format = core.lrucache.new({
- ttl = 300, count = 256
-})
+local _M = {name = "ewma"}
+local function lock(upstream)
+ local _, err = ewma_lock:lock(upstream .. LOCK_KEY)
+ if err and err ~= "timeout" then
+ core.log.error("EWMA Balancer failed to lock: ", err)
+ end
+
+ return err
+end
+
+local function unlock()
+ local ok, err = ewma_lock:unlock()
+ if not ok then
+ core.log.error("EWMA Balancer failed to unlock: ", err)
+ end
+
+ return err
+end
local function decay_ewma(ewma, last_touched_at, rtt, now)
local td = now - last_touched_at
@@ -35,73 +57,68 @@ local function decay_ewma(ewma, last_touched_at, rtt, now)
return ewma
end
-
local function store_stats(upstream, ewma, now)
local success, err, forcible = shm_last_touched_at:set(upstream, now)
if not success then
- core.log.error("balancer_ewma_last_touched_at:set failed ", err)
+ core.log.error("shm_last_touched_at:set failed: ", err)
end
if forcible then
- core.log.warn("balancer_ewma_last_touched_at:set valid items forcibly
overwritten")
+ core.log.warn("shm_last_touched_at:set valid items forcibly
overwritten")
end
success, err, forcible = shm_ewma:set(upstream, ewma)
if not success then
- core.log.error("balancer_ewma:set failed ", err)
+ core.log.error("shm_ewma:set failed: ", err)
end
if forcible then
- core.log.warn("balancer_ewma:set valid items forcibly overwritten")
+ core.log.warn("shm_ewma:set valid items forcibly overwritten")
end
end
-
local function get_or_update_ewma(upstream, rtt, update)
+ if update then
+ local lock_err = lock(upstream)
+ if lock_err ~= nil then
+ return 0, lock_err
+ end
+ end
+
local ewma = shm_ewma:get(upstream) or 0
+
local now = ngx_now()
local last_touched_at = shm_last_touched_at:get(upstream) or 0
ewma = decay_ewma(ewma, last_touched_at, rtt, now)
if not update then
- return ewma
+ return ewma, nil
end
store_stats(upstream, ewma, now)
- return ewma
+ unlock()
+
+ return ewma, nil
end
+local function get_upstream_name(upstream)
+ return upstream.host .. ":" .. upstream.port
+end
local function score(upstream)
-- Original implementation used names
- -- Endpoints don't have names, so passing in host:Port as key instead
- local upstream_name = upstream.host .. ":" .. upstream.port
+ -- Endpoints don't have names, so passing in IP:Port as key instead
+ local upstream_name = get_upstream_name(upstream)
return get_or_update_ewma(upstream_name, 0, false)
end
-
-local function pick_and_score(peers)
- local lowest_score_index = 1
- local lowest_score = score(peers[lowest_score_index])
- for i = 2, #peers do
- local new_score = score(peers[i])
- if new_score < lowest_score then
- lowest_score_index, lowest_score = i, new_score
- end
- end
-
- return peers[lowest_score_index], lowest_score
-end
-
-
local function parse_addr(addr)
local host, port, err = core.utils.parse_addr(addr)
return {host = host, port = port}, err
end
-
local function _trans_format(up_nodes)
-- trans
- --{"1.2.3.4:80":100,"5.6.7.8:8080":100}
+ -- {"1.2.3.4:80":100,"5.6.7.8:8080":100}
-- into
-- [{"host":"1.2.3.4","port":"80"},{"host":"5.6.7.8","port":"8080"}]
local peers = {}
@@ -119,38 +136,72 @@ local function _trans_format(up_nodes)
return next(peers) and peers or nil
end
-
local function _ewma_find(ctx, up_nodes)
local peers
- local endpoint
- if not up_nodes
- or core.table.nkeys(up_nodes) == 0 then
+ if not up_nodes or nkeys(up_nodes) == 0 then
return nil, 'up_nodes empty'
end
- peers = lrucache_trans_format(ctx.upstream_key, ctx.upstream_version,
- _trans_format, up_nodes)
+ if ctx.balancer_tried_servers and ctx.balancer_tried_servers_count ==
nkeys(up_nodes) then
+ return nil, "all upstream servers tried"
+ end
+
+ peers = lrucache_trans_format(ctx.upstream_key, ctx.upstream_version,
_trans_format, up_nodes)
if not peers then
return nil, 'up_nodes trans error'
end
- if #peers > 1 then
- endpoint = pick_and_score(peers)
+ local filtered_peers
+ if ctx.balancer_tried_servers then
+ for _, peer in ipairs(peers) do
+ if not ctx.balancer_tried_servers[get_upstream_name(peer)] then
+ if not filtered_peers then
+ filtered_peers = {}
+ end
+
+ table_insert(filtered_peers, peer)
+ end
+ end
else
- endpoint = peers[1]
+ filtered_peers = peers
end
- return endpoint.host .. ":" .. endpoint.port
-end
+ local endpoint = filtered_peers[1]
+
+ if #filtered_peers > 1 then
+ local a, b = math.random(1, #filtered_peers), math.random(1,
#filtered_peers - 1)
+ if b >= a then
+ b = b + 1
+ end
+
+ local backendpoint
+ endpoint, backendpoint = filtered_peers[a], filtered_peers[b]
+ if score(endpoint) > score(backendpoint) then
+ endpoint = backendpoint
+ end
+ end
+ return get_upstream_name(endpoint)
+end
local function _ewma_after_balance(ctx, before_retry)
if before_retry then
- -- don't count tries which fail to complete
+ if not ctx.balancer_tried_servers then
+ ctx.balancer_tried_servers =
core.tablepool.fetch("balancer_tried_servers", 0, 2)
+ end
+
+ ctx.balancer_tried_servers[ctx.balancer_server] = true
+ ctx.balancer_tried_servers_count = (ctx.balancer_tried_servers_count
or 0) + 1
+
return nil
end
+ if ctx.balancer_tried_servers then
+ core.tablepool.release("balancer_tried_servers",
ctx.balancer_tried_servers)
+ ctx.balancer_tried_servers = nil
+ end
+
local response_time = ctx.var.upstream_response_time or 0
local connect_time = ctx.var.upstream_connect_time or 0
local rtt = connect_time + response_time
@@ -163,21 +214,22 @@ local function _ewma_after_balance(ctx, before_retry)
return get_or_update_ewma(upstream, rtt, true)
end
-
function _M.new(up_nodes, upstream)
- if not shm_ewma
- or not shm_last_touched_at then
+ if not shm_ewma or not shm_last_touched_at then
return nil, "dictionary not find"
end
+ if not ewma_lock then
+ error(ewma_lock_err)
+ end
+
return {
upstream = upstream,
- get = function (ctx)
+ get = function(ctx)
return _ewma_find(ctx, up_nodes)
end,
after_balance = _ewma_after_balance
}
end
-
return _M
diff --git a/t/node/ewma.t b/t/node/ewma.t
index 955a6b7..53bf848 100644
--- a/t/node/ewma.t
+++ b/t/node/ewma.t
@@ -166,7 +166,7 @@ GET /t
return
end
- ngx.sleep(20)
+ ngx.sleep(11)
--keep the node 1980 hot
for i = 1, 12 do
local httpc = http.new()
@@ -215,3 +215,167 @@ GET /t
--- error_code: 200
--- no_error_log
[error]
+
+
+
+=== TEST 4: about filter tried servers
+--- timeout: 10
+--- config
+ location /t {
+ content_by_lua_block {
+ local t = require("lib.test_admin").test
+
+ --remove the 1981 node,
+ --add the 9527 node (invalid node)
+ --keep two nodes for triggering ewma logic in server_picker
function of balancer phase
+ local code, body = t('/apisix/admin/routes/1',
+ ngx.HTTP_PUT,
+ [[{
+ "upstream": {
+ "nodes": {
+ "127.0.0.1:1980": 1,
+ "127.0.0.1:9527": 1
+ },
+ "type": "ewma",
+ "timeout": {
+ "connect": 0.1,
+ "send": 0.5,
+ "read": 0.5
+ }
+ },
+ "uri": "/ewma"
+ }]]
+ )
+
+ if code ~= 200 then
+ ngx.say("update route failed")
+ return
+ end
+
+ local http = require "resty.http"
+ local uri = "http://127.0.0.1:"; .. ngx.var.server_port
+ .. "/ewma"
+
+ --should always select the 1980 node, because 0 is invalid
+ local t = {}
+ local ports_count = {}
+ for i = 1, 12 do
+ local th = assert(ngx.thread.spawn(function(i)
+ local httpc = http.new()
+ httpc:set_timeout(2000)
+ local res, err = httpc:request_uri(uri, {method = "GET",
keepalive = false})
+ if not res then
+ ngx.say(err)
+ return
+ end
+ ports_count[res.body] = (ports_count[res.body] or 0) + 1
+ end, i))
+ table.insert(t, th)
+ end
+ for i, th in ipairs(t) do
+ ngx.thread.wait(th)
+ end
+
+ local ports_arr = {}
+ for port, count in pairs(ports_count) do
+ table.insert(ports_arr, {port = port, count = count})
+ end
+
+ local function cmd(a, b)
+ return a.port > b.port
+ end
+ table.sort(ports_arr, cmd)
+
+ ngx.say(require("toolkit.json").encode(ports_arr))
+ ngx.exit(200)
+ }
+ }
+--- request
+GET /t
+--- response_body
+[{"count":12,"port":"1980"}]
+--- error_code: 200
+--- error_log
+Connection refused) while connecting to upstream
+
+
+
+=== TEST 5: about all endpoints have been retried
+--- timeout: 10
+--- config
+ location /t {
+ content_by_lua_block {
+ local t = require("lib.test_admin").test
+
+ --add the 9527 node (invalid node)
+ --add the 9528 node (invalid node)
+ --keep two nodes for triggering ewma logic in server_picker
function of balancer phase
+ local code, body = t('/apisix/admin/routes/1',
+ ngx.HTTP_PUT,
+ [[{
+ "upstream": {
+ "nodes": {
+ "127.0.0.1:9527": 1,
+ "127.0.0.1:9528": 1
+ },
+ "type": "ewma",
+ "timeout": {
+ "connect": 0.1,
+ "send": 0.5,
+ "read": 0.5
+ }
+ },
+ "uri": "/ewma"
+ }]]
+ )
+
+ if code ~= 200 then
+ ngx.say("update route failed")
+ return
+ end
+
+ local http = require "resty.http"
+ local uri = "http://127.0.0.1:"; .. ngx.var.server_port
+ .. "/ewma"
+
+ --should always return 502, because both 9527 and 9528 are invalid
+ local t = {}
+ local ports_count = {}
+ for i = 1, 12 do
+ local th = assert(ngx.thread.spawn(function(i)
+ local httpc = http.new()
+ httpc:set_timeout(2000)
+ local res, err = httpc:request_uri(uri, {method = "GET",
keepalive = false})
+ if not res then
+ ngx.say(err)
+ return
+ end
+ ports_count[res.status] = (ports_count[res.status] or 0) +
1
+ end, i))
+ table.insert(t, th)
+ end
+ for i, th in ipairs(t) do
+ ngx.thread.wait(th)
+ end
+
+ local ports_arr = {}
+ for port, count in pairs(ports_count) do
+ table.insert(ports_arr, {port = port, count = count})
+ end
+
+ local function cmd(a, b)
+ return a.port > b.port
+ end
+ table.sort(ports_arr, cmd)
+
+ ngx.say(require("toolkit.json").encode(ports_arr))
+ ngx.exit(200)
+ }
+ }
+--- request
+GET /t
+--- response_body
+[{"count":12,"port":502}]
+--- error_code: 200
+--- error_log
+Connection refused) while connecting to upstream
