Skywalking链路追踪--告警篇
1、概述
Skywalking
发送告警的基本原理是每隔一段时间轮询skywalking-oap
收集到的链路追踪的数据,再根据所配置的告警规则(如服务响应时间、服务响应时间百分比)等,如果达到阈值则发送响应的告警信息。
发送告警信息是以线程池异步的方式调用webhook
接口完成的,具体的webhook
接口可以由使用者自行定义,从而可以在指定的webhook
接口中自行编写各种告警方式,比如钉钉告警、邮件告警等等。告警的信息也可以在RocketBot
即ui
中查看到。
目前对应我前面文章中部署的8.5.0
版本支持的告警接口如下:
- 普通webhook
- gRPCHook
- Slack Chat Hook
- WeChat Hook(微信告警)
- Dingtalk Hook(钉钉告警)
- Feishu Hook(飞书告警)
2、告警规则
2.1 默认告警规则
在Skywalking
中,告警规则称为rule
,默认安装的Skywalking
oap server
组件中包含了告警规则的配置文件,位于安装目录下config
文件夹下alarm-settings.yml
文件中,在容器中运行的也是一样的
# kubectl -n devops exec -it skywalking-oap-57d7f454f5-w4k4j -- bash
bash-5.0# pwd
/skywalking
bash-5.0# cat config/alarm-settings.yml
以下是默认的告警规则配置文件内容
rules:
# Rule unique name, must be ended with `_rule`.
service_resp_time_rule:
metrics-name: service_resp_time
op: ">"
threshold: 1000
period: 10
count: 3
silence-period: 5
message: Response time of service {name} is more than 1000ms in 3 minutes of last 10 minutes.
service_sla_rule:
# Metrics value need to be long, double or int
metrics-name: service_sla
op: "<"
threshold: 8000
# The length of time to evaluate the metrics
period: 10
# How many times after the metrics match the condition, will trigger alarm
count: 2
# How many times of checks, the alarm keeps silence after alarm triggered, default as same as period.
silence-period: 3
message: Successful rate of service {name} is lower than 80% in 2 minutes of last 10 minutes
service_resp_time_percentile_rule:
# Metrics value need to be long, double or int
metrics-name: service_percentile
op: ">"
threshold: 1000,1000,1000,1000,1000
period: 10
count: 3
silence-period: 5
message: Percentile response time of service {name} alarm in 3 minutes of last 10 minutes, due to more than one condition of p50 > 1000, p75 > 1000, p90 > 1000, p95 > 1000, p99 > 1000
service_instance_resp_time_rule:
metrics-name: service_instance_resp_time
op: ">"
threshold: 1000
period: 10
count: 2
silence-period: 5
message: Response time of service instance {name} is more than 1000ms in 2 minutes of last 10 minutes
database_access_resp_time_rule:
metrics-name: database_access_resp_time
threshold: 1000
op: ">"
period: 10
count: 2
message: Response time of database access {name} is more than 1000ms in 2 minutes of last 10 minutes
endpoint_relation_resp_time_rule:
metrics-name: endpoint_relation_resp_time
threshold: 1000
op: ">"
period: 10
count: 2
message: Response time of endpoint relation {name} is more than 1000ms in 2 minutes of last 10 minutes
# Active endpoint related metrics alarm will cost more memory than service and service instance metrics alarm.
# Because the number of endpoint is much more than service and instance.
#
# endpoint_avg_rule:
# metrics-name: endpoint_avg
# op: ">"
# threshold: 1000
# period: 10
# count: 2
# silence-period: 5
# message: Response time of endpoint {name} is more than 1000ms in 2 minutes of last 10 minutes
webhooks:
# - http://127.0.0.1/notify/
# - http://127.0.0.1/go-wechat/
2.2 告警规则详解
下面取默认的告警规则中的一条进行分析
rules:
# Rule unique name, must be ended with `_rule`.
service_resp_time_rule:
metrics-name: service_resp_time
op: ">"
threshold: 1000
period: 10
count: 3
silence-period: 5
message: Response time of service {name} is more than 1000ms in 3 minutes of last 10 minutes.
首先提示声明了告警规则名称应该具有唯一性,且必须以 _rule
结尾,这里是service_resp_time_rule
(服务响应时间)
- metrics-name:告警指标,指标度量值为
long
、double
或int
类型 - op:度量值和阈值的比较方式,这里是大于
- threshold:阈值,这里是
1000
,毫秒为单位 - period:评估度量标准的时间长度,也就是告警检查周期,分钟为单位
- count:累计达到多少次告警值后触发告警
- silence-period:忽略相同告警信息的周期,默认与告警检查周期一致。简单来说,就是在触发告警时开始计时
N
,在N
+period
时间内保持沉默silence
不会再次触发告警,这和alertmanager
的告警抑制类似 - message:告警消息主体,通过变量在发送消息时进行自动替换
除此之外,还有以下可选(高级)规则配置:
到这里,就能分析出上面列出的所有默认告警规则的含义,依次为:
1 最近3分钟内服务平均响应时间超过1秒
2 最近2分钟内服务成功率低于80%
3 最近3分钟的服务响应时间百分位超过1秒
4 最近2分钟内服务实例的平均响应时间超过1秒
5 最近2分钟内数据库访问的平均响应时间超过1秒
6 最近2分钟内端点平均响应时间超过1秒
7 过去2分钟内端点关系的平均响应时间超过1秒
这条规则默认没有打开,并且提示:由于端点的数量远远多于服务和实例,活动端点相关度量告警将比服务和服务实例度量告警消耗更多内存
3、自定义告警规则
Skywalking
的配置大部分内容是通过应用的application.yml
及系统的环境变量设置的,同时也支持下面系统的动态配置来源
- gRPC服务
- Zookeeper
- Etcd
- Consul
- Apollo
- Nacos
- k8s configmap
参考Skywalking
动态配置说明,如果开启了动态配置,可以通过键alarm.default.alarm-settings
覆盖掉默认配置文件alarm-settings.yml
本文记录的是基于k8s
和helm
部署的Skywalking
,因此可以通过k8s-configmap
进行自定义配置的注入,最终在Skywalking
配置文件中的实现如下,此文件中有很多变量,通过分析chart
,发现已经写好逻辑会根据是否启用动态配置来自动注入所有变量,所以就无需在value.yaml
中声明了
cluster:
selector: ${SW_CLUSTER:standalone}
...
kubernetes:
namespace: ${SW_CLUSTER_K8S_NAMESPACE:default}
labelSelector: ${SW_CLUSTER_K8S_LABEL:app=collector,release=skywalking}
uidEnvName: ${SW_CLUSTER_K8S_UID:SKYWALKING_COLLECTOR_UID}
...
configuration:
selector: ${SW_CONFIGURATION:k8s-configmap}
...
k8s-configmap:
# Sync period in seconds. Defaults to 60 seconds.
period: ${SW_CONFIG_CONFIGMAP_PERIOD:60}
# Which namespace is confiigmap deployed in.
namespace: ${SW_CLUSTER_K8S_NAMESPACE:default}
# Labelselector is used to locate specific configmap
labelSelector: ${SW_CLUSTER_K8S_LABEL:app=collector,release=skywalking}
在自定义配置告警规则的同时加入webhook
后端报警相关配置,configmap
文件写法可以参考官方helm
configmap示例
我这里只把默认的报警规则提示信息改成了中文报警信息,具体每条规则的参数没有变化,同时还加入了钉钉webhook
配置,具体流程如下
修改chart
包的value.yaml
,开启动态配置
...
oap:
name: oap
dynamicConfigEnabled: true # 开启动态配置功能
...
修改chart
包中template
的oap-configmap.yaml
,配置自定义的rule
和企业微信webhook
如下 JVM 监控指标暂未实现(更新了策略)
{{- if .Values.oap.dynamicConfigEnabled }}
apiVersion: v1
kind: ConfigMap
metadata:
name: skywalking-dynamic-config
labels:
app: {{ template "skywalking.name" . }}
release: {{ .Release.Name }}
component: {{ .Values.oap.name }}
data:
alarm.default.alarm-settings: |-
rules:
# Rule unique name, must be ended with `_rule`.
service_resp_time_rule:
metrics-name: service_resp_time
op: ">"
threshold: 2000
period: 10
count: 3
silence-period: 5
message: 服务:{name}\n 指标:响应时间\n 详情:至少3次超过2秒(最近10分钟内)
service_sla_rule:
# Metrics value need to be long, double or int
metrics-name: service_sla
op: "<"
threshold: 8000
# The length of time to evaluate the metrics
period: 10
# How many times after the metrics match the condition, will trigger alarm
count: 3
# How many times of checks, the alarm keeps silence after alarm triggered, default as same as period.
silence-period: 3
message: 服务:{name}\n 指标:成功率\n 详情:至少3次低于80%(最近10分钟内)
service_resp_time_percentile_rule:
# Metrics value need to be long, double or int
metrics-name: service_percentile
op: ">"
threshold: 1000,1000,1000,1000,1000
period: 10
count: 3
silence-period: 5
message: 服务:{name}\n 指标:响应时间\n 详情:至少3次百分位超过1秒(最近10分钟内)
service_instance_resp_time_rule:
metrics-name: service_instance_resp_time
op: ">"
threshold: 2000
period: 10
count: 2
silence-period: 5
message: 实例:{name}\n 指标:响应时间\n 详情:至少2次超过2秒(最近10分钟内)
database_access_resp_time_rule:
metrics-name: database_access_resp_time
threshold: 2000
op: ">"
period: 10
count: 2
# message: Response time of database access {name} is more than 1000ms in 2 minutes of last 10 minutes
message: 数据库访问:{name}\n 指标:响应时间\n 详情:至少2次超过2秒(最近10分钟内)
endpoint_relation_resp_time_rule:
metrics-name: endpoint_relation_resp_time
threshold: 2000
op: ">"
period: 10
count: 2
message: 端点关系:{name}\n 指标:响应时间\n 详情:至少2次超过2秒(最近10分钟内)
instance_jvm_old_gc_count_rule:
metrics-name: instance_jvm_old_gc_count
threshold: 1
op: ">"
period: 1440
count: 1
message: 实例:{name}\n 指标:OldGC次数\n 详情:最近1天内大于1次
instance_jvm_young_gc_count_rule:
metrics-name: instance_jvm_young_gc_count
threshold: 1
op: ">"
period: 5
count: 100
message: 实例:{name}\n 指标:YoungGC次数\n 详情:最近5分钟内大于100次
# 需要在config/oal/core.oal添加一行:endpoint_abnormal = from(Endpoint.*).filter(responseCode in [404, 500, 503]).count();
endpoint_abnormal_rule:
metrics-name: endpoint_abnormal
threshold: 1
op: ">="
period: 2
count: 1
message: 接口:{name}\n 指标:接口异常\n 详情:最近2分钟内至少1次\n
wechatHooks:
textTemplate: |-
{
"msgtype": "text",
"text": {
"content": "SkyWalking 链路追踪告警: \n %s."
}
}
webhooks:
- https://qyapi.weixin.qq.com/cgi-bin/webhook/send?key=534bb833-a14d-4ea5-975a-032077e57ccc
{{- end }}
如上其中一个百分位的指标如下解释:
service_resp_time_percentile_rule:
# Metrics value need to be long, double or int
metrics-name: service_percentile
op: ">"
# Multiple value metrics threshold. Thresholds for P50, P75, P90, P95, P99.
threshold: 1000,1000,1000,1000,1000
period: 10
count: 3
silence-period: 5
message: Percentile response time of service {name} alarm in 3 minutes of last 10 minutes, due to more than one condition of p50 > 1000, p75 > 1000, p90 > 1000, p95 > 1000, p99 > 1000
修改完成后,执行helm
进行更新
$ cd /usr/local/src/zhdya/skywalking/skywalking-kubernetes/chart/
kd job skywalking-es-init -ndevops
$ helm upgrade skywalking skywalking -n devops --values ./skywalking/values.yaml
$ helm -n devops list
$ helm -n devops history skywalking
$ kgp -ndevops -owide
验证:XXXXX
结果:
到这里,在Skywalking
中配置报警就完成了 ~
附:在一次Skywalking
线上分享会上记录的关于使用Skywalking
定位问题的思路:
- 纵览全局,
Skywalking
拓扑图 - 监控告警,
metric
/tracing
确定问题存在故障(根据metric
做告警,根据tracing
统计作比较) - 确定故障在哪,
tracing
调用关系,确定故障出现在哪个service
或者endpoint
profile
手段(skywalking
新能力)或者常见传统性能定位方法,定位单节点问题所在(比如CPU
、内存、io
、网络 ——> 动态追踪采样 ——> 火焰图)基本可以解决99.9%的问题
如果要添加自定义告警,首先需要在 oal
文件中添加一个指标,
这里添加一个自定义告警:当接口返回状态码为 404,50, 502, 503, 504 其中一个,就发送告警
root@nx-eks-ctl:/usr/local/src/zhdya/skywalking/skywalking-kubernetes/chart/skywalking/files/conf.d# 下面有个README.md 文件,主要是为了介绍如何去自定义。
Files under `oap/*` will override the counterparts under the Docker image's `/skywalking/config/*`, with the directory structure retained, here are some examples:
| File under `files/config.d/oap` directory | Overrides the file under Docker image's `/skywalking/config/` |
| ---- | -------- |
| `files/config.d/oap/application.yml` | `/skywalking/config/application.yml` |
| `files/config.d/oap/log4j2.xml` | `/skywalking/config/log4j2.xml` |
| `files/config.d/oap/alarm-settings.yml` | `/skywalking/config/alarm-settings.yml` |
| `files/config.d/oap/endpoint-name-grouping.yml` | `/skywalking/config/endpoint-name-grouping.yml` |
| `files/config.d/oap/oal/core.oal` | `/skywalking/config/oal/core.oal` |
| `files/config.d/oap/oal/browser.oal` | `/skywalking/config/oal/browser.oal` |
| `files/config.d/oap/oc-rules/oap.yaml` | `/skywalking/config/oc-rules/oap.yaml` |
| `...` | `...` |
例如我需要变更core.oal,复制早先的所有内容,然后追加(需要先新建一个oal的):
// devops 20220704
endpoint_abnormal = from(Endpoint.*).filter(responseCode in [404, 500, 502, 503, 504]).count();
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