This topic describes the tracing protocols supported by Application Real-Time Monitoring Service (ARMS).
EagleEye protocol
The EagleEye protocol is developed by ARMS and is widely used in Alibaba Cloud.
The protocol header contains the following information:
EagleEye-TraceID: a 32-bit string. Format:
ea<8-bit IP code><13-bit timestamp><4-bit incremental ID>d<4-bit PID>. Example:eac0a8020216868084400006973d000a.EagleEye-RpcID: the hierarchical relationship between the spans. Example: 0, 0.1, 0.2, 0.1.1. In this example, 0 is the parent span, and 0.1 and 0.2 are the child spans.
EagleEye-SpanID: a random long integer compatible with open source redundant fields.
EagleEye-pSpanID: a random long integer compatible with open source redundant fields.
EagleEye-Sampled: specifies whether the traces are sampled.
EagleEye-pAppName: the upstream applications.
EagleEye-pRpc: the upstream application interface.
EagleEye-UserData: the baggage to be propagated in the traces. Format:
k1=v1&k2&v2.
OpenTelemetry protocol
The OpenTelemetry protocol is the default protocol used by OpenTelemetry.
The protocol header contains the following information:
traceparent: Format:
<2-bit version number>-<32-bit trace ID>-<16-bit parent span ID>-<Sampling identifier>. Example:00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01.tracestate: the baggage to be propagated in the traces. Example:
k1=v1&k2&v2.
Zipkin protocol
The Zipkin protocol is used by open source Zipkin.
The protocol header contains the following information:
X-B3-TraceId: a 32-bit trace ID. Example:
0af7651916cd43dd8448eb211c80319c.X-B3-SpanId: a 16-bit span ID. Example:
b7ad6b7169203331.X-B3-ParentSpanId: a 16-bit parent span ID. Example:
b7ad6b7169203331.X-B3-Sampled: the sampling identifier. For example, 1 indicates that the traces are sampled whereas 0 indicates that the traces are not.
baggage-: the baggage to be propagated in the traces. Example:
baggage-k1=v1, baggage-k2=v2.
Jaeger protocol
The Jaeger protocol is used by open source Jaeger.
The protocol header contains the following information:
uber-trace-id: Format:
traceId:spanId:parentSpanId:flag. Example:0af7651916cd43dd8448eb211c80319c:b7ad6b7169203331:b7ad6b7169203331:1.uberctx-: the baggage to be propagated in the traces. Example:
uberctx-k1=v1, uberctx-k2=v2.
SkyWalking protocol
The SkyWalking Protocol is used by open source SkyWalking.
sw8: consists of eight fields. Separate fields with hyphens (-). The default maximum number of characters in the protocol header must be less than 2,000. The protocol header contains the following fields. All string values must be Base64-encoded.
The following fields are required:
Sample: 0 or 1. 0 indicates that the context exists and can be ignored. 1 indicates that the traces need to be sampled and sent to the backend.
Trace Id: the unique identifier of the tracing operation. The value is a Base64-encoded string. The string consists of three long values that are separated with periods (.).
Parent trace segment Id: the globally unique segment ID. The value is a Base64-encoded string.
Parent span ID: 0 or a positive integer.
Parent service: a Base64-encoded string. The string must consist of more than 50 UTF-8 characters.
Parent service instance ID: a Base64-encoded string. The string must consist of more than 50 UTF-8 characters.
Parent service endpoint: the endpoint of the first entry span in the parent trace segment. The value is a Base64-encoded string. The string must consist of more than 50 UTF-8 characters.
Destination URL of the request: the URL of the destination service that the client wants to access. The format of the URL can be different from
<IP address><Port number>. The value is a Base64-encoded string.
Sample sw8 protocol header:
1-TRACEID-SEGMENTID-3-PARENT_SERVICE-PARENT_INSTANCE-PARENT_ENDPOINT-IPPORT.sw8-x: Separate fields with hyphens (-). Fields can be extended.
The tracking mode can be set to null, 0, or 1. The default value null or 0 indicates that all the spans generated in the context are not analyzed. Context is propagated upstream by default, unless changed during tracking.
Select a tracing protocol
The ARMS agent automatically identifies the protocol used in the current environment. If no protocol is used in the current environment, the ARMS tracing protocol is used by default.
Assume that A, B, and C are different applications. When a request is received, the system checks whether the ARMS, Jaeger, Zipkin, SkyWalking, and OpenTelemetry protocol headers exist in sequence. If one of the preceding protocol headers exists, the corresponding protocol is used. Otherwise, the ARMS tracing protocol is used by default.