Publishing Consumed Events to Prometheus Metrics and Exposing then via HTTP¶
Purpose:¶
This application demonstrates how to use siddhi-io-prometheus for publishing events through HTTP server.
Prerequisites:¶
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The following steps must be executed to enable WSO2 SP to publish events to Prometheus
- Download Prometheus server 'prometheus-2.5.0' from here : https://prometheus.io/download/#prometheus And extract the file in a preferred location.
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Open the prometheus.yml file from {prometheus} directory and add the following text under "scrape_configs:" " - job_name: 'server' honor_labels: true static_configs: - targets: ['localhost:9080']"
- you can replace values for 'localhost:9080' in targets according to your preferred host and port. In that case, the 'server.url' option must be included in the Sink definition with the same host and port values.
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Download and copy the prometheus client jars to the {WSO2SIHome}/lib directory as follows.
- Download the following jars from https://mvnrepository.com/artifact/io.prometheus and copy them to {WSO2SIHome}/lib directory.
- simpleclient_pushgateway-0.5.0.jar
- simpleclient_common-0.5.0.jar
- simpleclient-0.5.0.jar
- simpleclient_httpserver-0.5.0.jar
- Download the following jars from https://mvnrepository.com/artifact/io.prometheus and copy them to {WSO2SIHome}/lib directory.
- Navigate to {prometheus} and start prometheus server using ' ./prometheus --config.file="prometheus.yml" ' command
- Start the editor WSO2 SP by giving this command in the terminal : sh editor.sh
- Save this sample
Executing the Sample:¶
- Start the Siddhi application by clicking on 'Run'
- If the Siddhi application starts successfully, the following messages would be shown on the console,
- PublishPrometheusMetricHTTPServer.siddhi - Started Successfully!
- SweetProductionStream has successfully connected at http://localhost:9080
Testing the Sample:¶
- Send events through the event simulator:
- Open the event simulator by clicking on the second icon or pressing Ctrl+Shift+I.
- In the Single Simulation tab of the panel, specify the values as follows:
- Siddhi App Name : PublishPrometheusMetricHTTPServer
- Stream Name : SweetProductionStream
- In the name and amount fields, enter 'toffees' and '55.4' respectively and then click Send to send the event.
- Send some more events as follows, ['gingerbread', 72.3], ['toffees', 32.4], ['lollipop', 23.8].
Viewing the Results:¶
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See the output events through one or more of the following methods:
- Open the url "http://localhost:9080/metrics" in your browser. The following output will be displayed,
- "# HELP SweetProductionStream help for counter SweetProductionStream"
- "# TYPE SweetProductionStream counter"
- "SweetProductionStream{Name="gingerbread",} 72.3"
- "SweetProductionStream{Name="lollipop",} 23.8"
- "SweetProductionStream{Name="toffees",} 87.8""
- Open the url "http://localhost:9080/metrics" in your browser. The following output will be displayed,
-
Send HTTP request to the endpoint "http://localhost:9090" to the running prometheus server using the curl command:
- Open a new terminal and issue the following command:
- curl -X GET http://localhost:9090/
- If there is no error, the result will be shown on the terminal in JSON Format similar to the following :
{"status":"success", "data":{ "resultType":"vector", "result":[ { "metric":{"Name":"gingerbread", "__name__":"SweetProductionStream", "instance":"localhost:9080", "job":"server"}, "value":[1*********.***,"72.3"] }, { "metric":{"Name":"lollipop", "__name__":"SweetProductionStream", "instance":"localhost:9080", "job":"server"}, "value":[1*********.***,"23.8"] }, { "metric":{"Name":"toffees", "__name__":"SweetProductionStream", "instance":"localhost:9080", "job":"server"}, "value":[1*********.***,"87.8"] } ]} }
- Open a new terminal and issue the following command:
@App:name("PublishPrometheusMetrics")
@App:description('Publish consumed events to Prometheus metrics and expose them via http server.')
define stream FooStream(Name string, amount double);
@sink(type='log', priority='WARN', prefix ='received sweet products')
define stream LogStream(Name string, amount double);
@sink(type='prometheus' , job='SweetProduction', publish.mode='server', metric.type='counter', value.attribute = "amount", @map(type='keyvalue'))
define stream SweetProductionStream(Name string, amount double);
@info(name='Add-events')
from FooStream
select *
insert into SweetProductionStream;
@info(name='Log-events')
from FooStream
select *
insert into LogStream;
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