fix: removed plugin API and use background timer

apache · Dec 3, 2020 · 2a04e5e · 2a04e5e
1 parent 2ec4569
commit 2a04e5e
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Showing 6 changed files with 99 additions and 160 deletions.
diff --git a/apisix/plugins/server-info.lua b/apisix/plugins/server-info.lua
@@ -16,15 +16,15 @@
 --
 local require = require
 local core = require("apisix.core")
+local timers = require("apisix.timers")
 
 local ngx_time = ngx.time
 local ngx_timer_at = ngx.timer.at
-local ngx_worker_id = ngx.worker.id
 local type = type
+local ceil = math.ceil
 
-local plugin_name = "server-info"
 local boot_time = os.time()
-local current_timer
+local plugin_name = "server-info"
 local schema = {
     type = "object",
     additionalProperties = false,
@@ -38,6 +38,13 @@ local attr_schema = {
             default = 60,
             minimum = 60,
             maximum = 3600,
+        },
+        report_ttl = {
+            type = "integer",
+            description = "live time for server info in etcd",
+            default = 7200,
+            minimum = 3600,
+            maximum = 86400,
         }
     }
 }
@@ -116,18 +123,11 @@ local function get()
 end
 
 
-local function get_server_info()
-    local server_info, err = get()
-    if not server_info then
-        core.log.error("failed to get server_info: ", err)
-        return 500, err
+local function report(premature, report_ttl)
+    if premature then
+        return
     end
 
-    return 200, core.json.encode(server_info)
-end
-
-
-local function report()
     local server_info, err = get()
     if not server_info then
         core.log.error("failed to get server_info: ", err)
@@ -158,7 +158,7 @@ local function report()
     end
 
     local key = "/data_plane/server_info/" .. server_info.id
-    local ok, err = core.etcd.set(key, data, 180)
+    local ok, err = core.etcd.set(key, data, report_ttl)
     if not ok then
         core.log.error("failed to report server info to etcd: ", err)
         return
@@ -183,11 +183,6 @@ end
 
 
 function _M.init()
-    if ngx_worker_id() ~= 0 then
-        -- only let the No.0 worker to launch timer for server info reporting.
-        return
-    end
-
     local ok, err = encode_and_save(uninitialized_server_info(), true)
     if not ok then
         core.log.error("failed to encode and save server info: ", err)
@@ -207,68 +202,33 @@ function _M.init()
         return
     end
 
-    local report_interval = attr.report_interval
-
-    -- we don't use core.timer and the apisix.timers here for:
-    -- 1. core.timer is not cancalable, timers will be leaked if plugin
-    -- reloading happens.
-    -- 2. the background timer in apisix.timers fires per 500 milliseconds, if
-    -- report_interval is not multiple of 0.5, the real report interval will be
-    -- inaccurate over time.
-    local fn
-    fn = function(premature, timer)
-        if premature or timer.cancelled then
-            return
-        end
-
-        report()
+    local threshold = ceil(attr.report_interval / timers.check_interval())
+    local report_ttl = attr.report_ttl
+    local count = 0
 
-        if not timer.cancelled then
-            local ok, err = ngx_timer_at(report_interval, fn, timer)
-            if not ok then
-                core.log.error("failed to create timer to report server info: ", err)
-            end
-
-        else
-            core.log.warn("server info report timer is cancelled")
+    local fn = function()
+        count = count + 1
+        if count == threshold then
+            report(nil, report_ttl)
+            count = 0
         end
     end
 
-    current_timer = {
-        cancelled = false
-    }
-
-    local ok, err = ngx_timer_at(0, fn, current_timer)
-    if ok then
-        core.log.info("timer created to report server info, interval: ",
-                      report_interval)
-    else
-        core.log.error("failed to create timer to report server info: ", err)
-    end
-end
-
-
-function _M.destory()
-    if ngx_worker_id() ~= 0 then
-        -- timer exists only in the No.0 worker.
+    local ok, err = ngx_timer_at(0, report, report_ttl)
+    if not ok then
+        core.log.error("failed to create initial timer to report server info: ", err)
         return
     end
 
-    if current_timer then
-        current_timer.cancelled = true
-        current_timer = nil
-    end
+    timers.register_timer("plugin#server-info", fn, true)
+
+    core.log.info("timer created to report server info, interval: ",
+                  attr.report_interval)
 end
 
 
-function _M.api()
-    return {
-        {
-            methods = {"GET"},
-            uri = "/apisix/server_info",
-            handler = get_server_info,
-        },
-    }
+function _M.destory()
+    timers.unregister_timer("plugin#server-info", true)
 end
 
 

diff --git a/apisix/timers.lua b/apisix/timers.lua
@@ -21,6 +21,7 @@ local unpack = unpack
 local thread_spawn = ngx.thread.spawn
 local thread_wait = ngx.thread.wait
 
+local check_interval = 0.5
 
 local timers = {}
 
@@ -57,7 +58,12 @@ end
 
 
 function _M.init_worker()
-    local timer, err = core.timer.new("background", background_timer, {check_interval = 0.5})
+    local opts = {
+        check_interval = check_interval,
+        sleep_succ = 0,
+        each_ttl = 0,
+    }
+    local timer, err = core.timer.new("background", background_timer, opts)
     if not timer then
         core.log.error("failed to create background timer: ", err)
         return
@@ -85,4 +91,9 @@ function _M.unregister_timer(name, privileged)
 end
 
 
+function _M.check_interval()
+    return check_interval
+end
+
+
 return _M
diff --git a/conf/config-default.yaml b/conf/config-default.yaml
@@ -255,3 +255,4 @@ plugin_attr:
     export_uri: /apisix/prometheus/metrics
   server-info:
     report_interval: 60 # server info report interval (unit: second)
+    report_ttl: 3600    # live time for server info in etcd (unit: second)
diff --git a/doc/plugins/server-info.md b/doc/plugins/server-info.md
@@ -23,24 +23,33 @@
 
 - [**Name**](#name)
 - [**Attributes**](#attributes)
-- [**API**](#api)
+- [API](#api)
 - [**How To Enable**](#how-to-enable)
 - [**Test Plugin**](#test-plugin)
 - [**Disable Plugin**](#disable-plugin)
 
 ## Name
 
-`server-info` is a plugin that reports basic server information to etcd periodically and allows us to get them in the data plane through it's API.
+`server-info` is a plugin that reports basic server information to etcd periodically.
+
+The meaning of each item in server information is following:
+
+| Name    | Type | Description |
+|---------|------|-------------|
+| up_time | integer | Elapsed time since APISIX instance was launched, value will be reset when you hot updating APISIX but is kept for intact if you just reloading APISIX. |
+| last_report_time | integer | Last reporting timestamp. |
+| id | string | APISIX instance id. |
+| etcd_version | string | The etcd cluster version that APISIX is using, value will be `"unknown"` if the network (to etcd) is partitioned. |
+| version | string | APISIX version. |
+| hostname | string | Hostname of the machine/pod that APISIX is deployed. |
 
 ## Attributes
 
 None
 
 ## API
 
-This plugin now exposes only one API `/apisix/server_info` to get basic server information.
-You may need to use [interceptors](../plugin-interceptors.md) to protect it.
-
+None
 
 ## How to Enable
 
@@ -57,48 +66,27 @@ plugins:                          # plugin list
   ......
 ```
 
-After starting APISIX and accessing `/apisix/server_info` then you can get server information.
+## How to customize the server info report configurations
 
-## How to customize the server info report interval
-
-We can change the report interval in the `plugin_attr` section of `conf/config.yaml`.
+We can change the report configurations in the `plugin_attr` section of `conf/config.yaml`.
 
 | Name         | Type   | Default  | Description                                                          |
 | ------------ | ------ | -------- | -------------------------------------------------------------------- |
-| report_interval | number | 60 | the interval (unit: second) to report server info to etcd.              |
+| report_interval | integer | 60 | the interval to report server info to etcd (unit: second, maximum: 3600, minimum: 60). |
+| report_ttl | integer | 7200 | the live time for server info in etcd (unit: second, maximum: 86400, minimum: 3600). |
 
-Here is an example, which modifies the report interval to 10 seconds.
+Here is an example, which modifies the `report_interval` to 10 minutes and sets the `report_ttl` to one hour.
 
 ```yaml
 plugin_attr:
   server-info:
-    report_interval: 10
+    report_interval: 600,
+    report_ttl: 3600
 ```
 
 ## Test Plugin
 
-```bash
-curl http://127.0.0.1:9080/apisix/server_info -s | jq
-{
-  "up_time": 5,
-  "last_report_time": 1606551536,
-  "id": "71cb4999-4349-475d-aa39-c703944a63d3",
-  "etcd_version": "3.5.0",
-  "version": "2.0",
-  "hostname": "gentoo"
-}
-```
-
-The meaning of each item in server information is following:
-
-| Name    | Type | Description |
-|---------|------|-------------|
-| up_time | integer | Elapsed time since APISIX instance was launched, value will be reset when you hot updating APISIX but is kept for intact if you just reloading APISIX. |
-| last_report_time | integer | Last reporting timestamp. |
-| id | string | APISIX instance id. |
-| etcd_version | string | The etcd cluster version that APISIX is using, value will be `"unknown"` if the network (to etcd) is partitioned. |
-| version | string | APISIX version. |
-| hostname | string | Hostname of the machine/pod that APISIX is deployed. |
+The APISIX Dashboard will collects server info in etcd, after enabling this plugin, you may try to check them through Dashboard.
 
 ## Disable Plugin
 

diff --git a/doc/zh-cn/plugins/server-info.md b/doc/zh-cn/plugins/server-info.md
@@ -31,15 +31,27 @@
 
 ## 插件简介
 
-`server-info` 是一款能够定期将服务基本信息上报至 etcd，同时允许我们通过它提供的 API 在数据面访问到这些数据的插件。
+`server-info` 是一款能够定期将服务基本信息上报至 etcd 的插件。
+
+服务信息中每一项的含义如下：
+
+| 名称    | 类型 | 描述 |
+|---------|------|-------------|
+| up_time | integer | APISIX 服务实例当前的运行时间, 如果对 APSIX
+进行热更新操作，该值将被重置；普通的 reload 操作不会影响该值。 |
+| last_report_time | integer | 最近一次服务信息上报的时间 （UNIX 时间戳）。|
+| id | string | APISIX 服务实例 id 。|
+| etcd_version | string | etcd 集群的版本信息，如果 APISIX 和 etcd 集群之间存在网络分区，该值将设置为 `"unknown"`。|
+| version | string | APISIX 版本信息。 |
+| hostname | string | APISIX 所部署的机器或 pod 的主机名信息。|
 
 ## 插件属性
 
 无
 
 ## 插件接口
 
-此插件提供了接口 `/apisix/server_info`，可以通过 [interceptors](../plugin-interceptors.md) 来保护该接口。
+无
 
 ## 启用插件
 
@@ -56,50 +68,32 @@ plugins:                          # plugin list
   ......
 ```
 
-在启动 APISIX 之后，即可通过访问 `/apisix/server_info` 来获取服务基本信息。
+## 如何自定义服务信息上报配置
 
-## 如何自定义服务信息上报间隔
-
-我们可以在 `conf/config.yaml` 文件的 `plugin_attr` 一节中修改上报间隔。
+我们可以在 `conf/config.yaml` 文件的 `plugin_attr` 一节中修改上报配置。
 
 | 名称         | 类型   | 默认值  | 描述                                                          |
 | ------------ | ------ | -------- | -------------------------------------------------------------------- |
-| report_interval | number | 60 | 上报服务信息至 etcd 的间隔（单位：秒）|
+| report_interval | integer | 60 | 上报服务信息至 etcd
+的间隔（单位：秒，最大值：3600，最小值：60）|
+| report_ttl | integer | 7200 | etcd 中服务信息保存的
+TTL（单位：秒，最大值：86400，最小值：3600）|
 
-下面的例子将服务信息上报间隔修改成了 10 秒：
+下面的例子将 `report_interval` 修改成了 10 秒，并将 `report_ttl` 修改成了 1
+小时：
 
 ```yaml
 plugin_attr:
   server-info:
     report_interval: 10
+    report_ttl: 3600
 ```
 
 
 ## 测试插件
 
-```bash
-curl http://127.0.0.1:9080/apisix/server_info -s | jq
-{
-  "up_time": 5,
-  "last_report_time": 1606551536,
-  "id": "71cb4999-4349-475d-aa39-c703944a63d3",
-  "etcd_version": "3.5.0",
-  "version": "2.0",
-  "hostname": "gentoo"
-}
-```
-
-服务信息中每一项的含义如下：
+Apache APISIX Dashboard 会收集上报到 etcd 中的服务信息，在启用这个插件后，你可以通过 APISIX Dashboard 来查看这些数据。
 
-| 名称    | 类型 | 描述 |
-|---------|------|-------------|
-| up_time | integer | APISIX 服务实例当前的运行时间, 如果对 APSIX
-进行热更新操作，该值将被重置；普通的 reload 操作不会影响该值。 |
-| last_report_time | integer | 最近一次服务信息上报的时间 （UNIX 时间戳）。|
-| id | string | APISIX 服务实例 id 。|
-| etcd_version | string | etcd 集群的版本信息，如果 APISIX 和 etcd 集群之间存在网络分区，该值将设置为 `"unknown"`。|
-| version | string | APISIX 版本信息。 |
-| hostname | string | APISIX 所部署的机器或 pod 的主机名信息。|
 
 ## 禁用插件