Tracing can be set up to monitor and track requests, optimize performance and latency, improve observability, and preform root cause and service dependency analysis. greymatter.io supports Envoy’s tracing capabilities for the visualization of call flows.
Configuration Reference
To properly set up tracing in greymatter.io, there must be a tracing server running with known address and port at the time the Sidecar is deployed. The Sidecar takes a series of run-time environment variables to set up a static cluster as the tracing server and configure its HTTP tracer. Then, the listener object takes a tracing configuration to configure specifics about the information in the spans.
Tracing can then be configured using the tracing_config field of any listener object. Properly configured, the Sidecar will send spans to the trace collector server with information on the request and its path through the mesh.
Sidecar Runtime Config
| Environment Variable | Type | Default | Description |
|---|---|---|---|
tracing_enabled |
|
| Indicates whether or not to enable tracing. |
tracing_address |
|
| The host for the trace collector server. |
tracing_port |
|
| The port for the trace collector server. |
tracing_collector_endpoint |
|
| The endpoint on the tracing server to send spans. |
tracing_use_tls` |
|
| Use TLS to connect to trace collector server. If true, tracing_ca_cert_path, tracing_cert_path, and tracing_key_path should be set. |
tracing_ca_cert_path |
|
| The path to the CA certificate. |
tracing_cert_path |
|
| The path to the certificate file. |
tracing_key_path |
|
| The path to the key file. |
Fabric tracing_config
Set in the listener object.
| Attribute | Type | Default | Description |
|---|---|---|---|
ingress |
|
| Does the listener trace incoming or outgoing traffic? |
request_headers_for_tags |
|
| Headers to convert into trace tags. |
Detailed Configuration
Listener Tracing Config
ingress
The boolean value set for ingress determines the operation_name value in the Envoy HTTP connection manager tracing configuration. By default in both greymatter.io and Envoy, ingress is true and "operation_name": "INGRESS". If ingress is set to false, operation_name will be "operation_name": "EGRESS". This determines the traffic direction of the trace.
request_headers_for_tags
This field takes a list of header names to create tags for the active span. By default it is null, and no tags are configured. If values are configured, a tag is created if the value is present in the requests headers, with the header name used as the tag name, and the header value used as the tag value in a span.
Examples
Sidecar Deployment
The below example uses a k8s deployment only as reference. The key points from the example are the TRACING_* environment variables set.
apiVersion: apps/v1
kind: Deployment
metadata:
name: myService
spec:
replicas: 3
selector:
matchLabels:
app: myService
template:
metadata:
labels:
app: myService
spec:
containers:
- name: sidecar
image: docker.greymatter.io/internal/example-service:latest
ports:
- name: http
containerPort: 8080
- name: metrics
containerPort: 8081
env:
- name: PROXY_DYNAMIC
value: "true"
- name: XDS_CLUSTER
value: myService
- name: XDS_HOST
value: gm-control
- name: XDS_PORT
value: "50000"
- name: TRACING_ENABLED
value: "true"
- name: TRACING_ADDRESS
value: "jaeger"
- name: TRACING_PORT
value: "9411"
Listener
Once the greymatter.io Sidecar is configured to talk to a trace server, the tracing_config on the greymatter.io listener for the desired service configures the mesh to start sending traces to this server.
The listener object with tracing_config set will look something like the following:
{
"listener_key": "example-listener",
...
"tracing_config": {
"ingress": true,
"request_headers_for_tags": null
},
...
}
The values configured in this field will be used to set the tracing options in Envoy and configure specifics about the trace’s sent to the server.
Trace
The traces will be sent to the server and a trace object in JSON will look something like:
{
"data": [
{
"traceID": "ccb5ba44bf450e9b",
"spans": [
{
"traceID": "ccb5ba44bf450e9b",
"spanID": "5b1cc9e0a6db97ab",
"operationName": "localhost:8080",
"references": [
{
"refType": "CHILD_OF",
"traceID": "ccb5ba44bf450e9b",
"spanID": "ccb5ba44bf450e9b"
}
],
"startTime": 1582125495267502,
"duration": 1775,
"tags": [
{
"key": "component",
"type": "string",
"value": "proxy"
},
{
"key": "node_id",
"type": "string",
"value": "d885090f63ffa467"
},
{
"key": "zone",
"type": "string",
"value": "default-zone"
},
{
"key": "guid:x-request-id",
"type": "string",
"value": "8f313280-1fcc-93d9-8c34-678e528bc10c"
},
{
"key": "http.url",
"type": "string",
"value": "http://localhost:8080/default/"
},
{
"key": "http.method",
"type": "string",
"value": "GET"
},
{
"key": "downstream_cluster",
"type": "string",
"value": "-"
},
{
"key": "user_agent",
"type": "string",
"value": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36"
},
{
"key": "http.protocol",
"type": "string",
"value": "HTTP/1.1"
},
{
"key": "request_size",
"type": "string",
"value": "0"
},
{
"key": "upstream_cluster",
"type": "string",
"value": "service"
},
{
"key": "http.status_code",
"type": "string",
"value": "304"
},
{
"key": "response_size",
"type": "string",
"value": "0"
},
{
"key": "response_flags",
"type": "string",
"value": "-"
},
{
"key": "span.kind",
"type": "string",
"value": "client"
},
{
"key": "internal.span.format",
"type": "string",
"value": "zipkin"
}
],
"logs": [],
"processID": "p1",
"warnings": null
}
],
"processes": {
"p1": {
"serviceName": "sidecar",
"tags": [
{
"key": "ip",
"type": "string",
"value": "172.23.0.6"
}
]
},
"p2": {
"serviceName": "myService",
"tags": [
{
"key": "ip",
"type": "string",
"value": "172.23.0.7"
}
]
}
},
"warnings": null
}
],
"total": 0,
"limit": 0,
"offset": 0,
"errors": null
}