Jaeger 是Uber推出的一款开源分布式追踪系统，兼容OpenTracing API。分布式追踪系统用于记录请求范围内的信息，包括一次调用的服务链路以及每个服务的延时，能够帮助我们很好的分析微服务间链路调用的错误及瓶颈。
OpenTracing api 及其原理将在下一篇 blog 中介绍。由于 istio 默认支持 Jaeger，因此准备测试下 Jaeger与Istio的集成。
Jaeger 整体架构如下图，主要包括3个组件： agent，collector以及query(UI)
agent: 用于监听应用传来的链路信息，并传递给collector，
collector：收集链路信息，并持久化。 其支持的后端存储为 Cassandra、ElasticSearch。此外也支持对接 Kafka，以进行后续的流式处理（可连入 spark、flink 以进一步分析）
query：提供查询的 api 接口及 UI 界面
在 istio 中，我们可以不部署 agent 组件。因为在 istio 中，若在 mixer 组件配置 zipkin-address-url 参数，则会默认为服务网格中的服务创建调用链路信息，并发送到配置的地址中。
这里的zipkin-address-url 并非真正部署的 zipkin， 而是这个地址可以兼容 zipkin 所使用的数据格式。
1.all-in-one
由于 all-in-one 模式是用于测试的demo，因此所有的链路信息默认存储在内存中，无法用于生产环境。
若单独在 K8s 平台中， Jaeger 官方推荐使用 Jaeger Operator 部署。Operator 部署相对来说比较简单，参考连接https://www.jaegertracing.io/docs/1.14/operator/，此处不再赘述。
Operator 是 K8s 平台提供的一种可自定义 Controller 的方式，此外仍需定义一系列的 CRD，自定义 Operator通过监听 CRD 的状态更新，实现一系列的逻辑，比如创建 deployment 等。
2.生产环境部署
zipkin: address: zipkin.istio-system:9411
#jaeger-cm.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: jaeger-configuration
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
data:
span-storage-type: elasticsearch
collector: |
es:
server-urls: http://es-ip:9200
collector:
zipkin:
http-port: 9411
query: |
es:
server-urls: http://es-ip:9200
agent: |
collector:
host-port: "jaeger-collector:14267"
#ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
ingress.kubernetes.io/protocol: http
name: istio-jaeger
namespace: istio-system
spec:
rules:
- host: domain
http:
paths:
- backend:
service:
name: jaeger-query
port:
name: jaeger-query
path: /
pathType: ImplementationSpecific
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: jaeger-collector
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
strategy:
type: Recreate
template:
metadata:
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
annotations:
prometheus.io/scrape: "true"
prometheus.io/port: "14268"
spec:
containers:
- image: jaegertracing/jaeger-collector:1.23.0
name: jaeger-collector
args: ["--config-file=/conf/collector.yaml"]
ports:
- containerPort: 14267
protocol: TCP
- containerPort: 14268
protocol: TCP
- containerPort: 9411
protocol: TCP
readinessProbe:
httpGet:
path: "/"
port: 14269
volumeMounts:
- name: jaeger-configuration-volume
mountPath: /conf
env:
- name: SPAN_STORAGE_TYPE
valueFrom:
configMapKeyRef:
name: jaeger-configuration
key: span-storage-type
volumes:
- configMap:
name: jaeger-configuration
items:
- key: collector
path: collector.yaml
name: jaeger-configuration-volume
---
apiVersion: v1
kind: Service
metadata:
name: jaeger-collector
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
spec:
ports:
- name: jaeger-collector-tchannel
port: 14267
protocol: TCP
targetPort: 14267
- name: jaeger-collector-http
port: 14268
protocol: TCP
targetPort: 14268
- name: jaeger-collector-zipkin
port: 9411
protocol: TCP
targetPort: 9411
selector:
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
type: ClusterIP
---
apiVersion: v1
kind: Service
metadata:
name: zipkin
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: zipkin
spec:
ports:
- name: jaeger-collector-zipkin
port: 9411
protocol: TCP
targetPort: 9411
selector:
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: collector
type: ClusterIP
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: jaeger-query
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: query
spec:
replicas: 1
strategy:
type: Recreate
selector:
matchLabels:
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: query
template:
metadata:
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: query
annotations:
prometheus.io/scrape: "true"
prometheus.io/port: "16686"
spec:
containers:
- image: jaegertracing/jaeger-query:1.23.0
name: jaeger-query
args: ["--config-file=/conf/query.yaml"]
ports:
- containerPort: 16686
protocol: TCP
readinessProbe:
httpGet:
path: "/"
port: 16687
volumeMounts:
- name: jaeger-configuration-volume
mountPath: /conf
env:
- name: SPAN_STORAGE_TYPE
valueFrom:
configMapKeyRef:
name: jaeger-configuration
key: span-storage-type
volumes:
- configMap:
name: jaeger-configuration
items:
- key: query
path: query.yaml
name: jaeger-configuration-volume
---
apiVersion: v1
kind: Service
metadata:
name: jaeger-query
namespace: istio-system
labels:
app: jaeger
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: query
spec:
ports:
- name: jaeger-query
port: 80
protocol: TCP
targetPort: 16686
selector:
app.kubernetes.io/name: jaeger
app.kubernetes.io/component: query
---
