telegraf/plugins/inputs/zipkin/README.md

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# Zipkin Plugin
This plugin implements the Zipkin http server to gather trace and timing data needed to troubleshoot latency problems in microservice architectures.
*Please Note: This plugin is experimental; Its data schema may be subject to change
based on its main usage cases and the evolution of the OpenTracing standard.*
## Configuration:
```toml
[[inputs.zipkin]]
path = "/api/v1/spans" # URL path for span data
port = 9411 # Port on which Telegraf listens
```
## Tracing:
This plugin uses Annotations tags and fields to track data from spans
- __TRACE:__ is a set of spans that share a single root span.
Traces are built by collecting all Spans that share a traceId.
- __SPAN:__ is a set of Annotations and BinaryAnnotations that correspond to a particular RPC.
- __Annotations:__ for each annotation & binary annotation of a span a metric is output. *Records an occurrence in time at the beginning and end of a request.*
Annotations may have the following values:
- __CS (client start):__ beginning of span, request is made.
- __SR (server receive):__ server receives request and will start processing it
network latency & clock jitters differ it from cs
- __SS (server send):__ server is done processing and sends request back to client
amount of time it took to process request will differ it from sr
- __CR (client receive):__ end of span, client receives response from server
RPC is considered complete with this annotation
### Tags
* __"id":__ The 64 bit ID of the span.
* __"parent_id":__ An ID associated with a particular child span. If there is no child span, the parent ID is set to ID.
* __"trace_id":__ The 64 or 128-bit ID of a particular trace. Every span in a trace shares this ID. Concatenation of high and low and converted to hexadecimal.
* __"name":__ Defines a span
##### Annotations have these additional tags:
* __"service_name":__ Defines a service
* __"annotation":__ The value of an annotation
* __"endpoint_host":__ Listening port concat with IPV4, if port is not present it will not be concatenated
##### Binary Annotations have these additional tag:
* __"service_name":__ Defines a service
* __"annotation":__ The value of an annotation
* __"endpoint_host":__ Listening port concat with IPV4, if port is not present it will not be concatenated
* __"annotation_key":__ label describing the annotation
### Fields:
* __"duration_ns":__ The time in nanoseconds between the end and beginning of a span.
### Sample Queries:
__Get All Span Names for Service__ `my_web_server`
```sql
SHOW TAG VALUES FROM "zipkin" with key="name" WHERE "service_name" = 'my_web_server'
```
- __Description:__ returns a list containing the names of the spans which have annotations with the given `service_name` of `my_web_server`.
__Get All Service Names__
```sql
SHOW TAG VALUES FROM "zipkin" WITH KEY = "service_name"
```
- __Description:__ returns a list of all `distinct` endpoint service names.
__Find spans with longest duration__
```sql
SELECT max("duration_ns") FROM "zipkin" WHERE "service_name" = 'my_service' AND "name" = 'my_span_name' AND time > now() - 20m GROUP BY "trace_id",time(30s) LIMIT 5
```
- __Description:__ In the last 20 minutes find the top 5 longest span durations for service `my_server` and span name `my_span_name`
### Recommended InfluxDB setup
This test will create high cardinality data so we reccomend using the [tsi influxDB engine](https://www.influxdata.com/path-1-billion-time-series-influxdb-high-cardinality-indexing-ready-testing/).
#### How To Set Up InfluxDB For Work With Zipkin
##### Steps
1. ___Update___ InfluxDB to >= 1.3, in order to use the new tsi engine.
2. ___Generate___ a config file with the following command:
```sh
influxd config > /path/for/config/file
```
3. ___Add___ the following to your config file, under the `[data]` tab:
```toml
[data]
index-version = "tsi1"
```
4. ___Start___ `influxd` with your new config file:
```sh
influxd -config=/path/to/your/config/file
```
5. ___Update___ your retention policy:
```sql
ALTER RETENTION POLICY "autogen" ON "telegraf" DURATION 1d SHARD DURATION 30m
```
### Example Input Trace:
- [Cli microservice with two services Test](https://github.com/openzipkin/zipkin-go-opentracing/tree/master/examples/cli_with_2_services)
- [Test data from distributed trace repo sample json](https://github.com/mattkanwisher/distributedtrace/blob/master/testclient/sample.json)
#### [Trace Example from Zipkin model](http://zipkin.io/pages/data_model.html)
```json
{
"traceId": "bd7a977555f6b982",
"name": "query",
"id": "be2d01e33cc78d97",
"parentId": "ebf33e1a81dc6f71",
"timestamp": 1458702548786000,
"duration": 13000,
"annotations": [
{
"endpoint": {
"serviceName": "zipkin-query",
"ipv4": "192.168.1.2",
"port": 9411
},
"timestamp": 1458702548786000,
"value": "cs"
},
{
"endpoint": {
"serviceName": "zipkin-query",
"ipv4": "192.168.1.2",
"port": 9411
},
"timestamp": 1458702548799000,
"value": "cr"
}
],
"binaryAnnotations": [
{
"key": "jdbc.query",
"value": "select distinct `zipkin_spans`.`trace_id` from `zipkin_spans` join `zipkin_annotations` on (`zipkin_spans`.`trace_id` = `zipkin_annotations`.`trace_id` and `zipkin_spans`.`id` = `zipkin_annotations`.`span_id`) where (`zipkin_annotations`.`endpoint_service_name` = ? and `zipkin_spans`.`start_ts` between ? and ?) order by `zipkin_spans`.`start_ts` desc limit ?",
"endpoint": {
"serviceName": "zipkin-query",
"ipv4": "192.168.1.2",
"port": 9411
}
},
{
"key": "sa",
"value": true,
"endpoint": {
"serviceName": "spanstore-jdbc",
"ipv4": "127.0.0.1",
"port": 3306
}
}
]
}
```