Use startSpan Set Mariadb But Haven’t Seen It On Destination And Service Map

[KURT07 (KURT)]

Use startSpan set Mariadb
i’ve Seen Type Mariadb On Timeline
But Haven’t Seen It On Destination And Service Map

APM Server version:
8.5.3

APM Agent language and version:
elastic-apm-node : 3.41.1

// My code
const transaction = Agent.currentTransaction;
const dbSpan = transaction.startSpan();
dbSpan.type = "db";
dbSpan.subtype = "mariadb";
dbSpan.action = "query";
dbSpan.name = "SELECT 1";
dbSpan.end();

Any idea what Im doing wrong?
Please Help
Many Thanks.

[trentm (Trent Mick)]

Hi @KURT07. Thanks for the question.

Try this:

var apm = require('./').start({
    serviceName: 'mariadb-example',
    metricsInterval: '0s'
})

function main() {
    const transaction = apm.startTransaction('manual')
    const dbSpan = transaction.startSpan('SELECT 1', 'db', 'mariadb', 'query', { exitSpan: true })
    // ...
    dbSpan.end()
    transaction.end()
}

main()

The important difference here is the exitSpan: true option when creating the span. The APM agent only normally includes so-called "exit" spans -- spans that represent a call to an external service -- for Service Maps and Dependencies.

When a span is marked as an exit span, then it will set a reasonable value for service target fields used for the Service Map node. By default it uses the span.subtype -- in this case "mariadb".

If you want to further customize that, for example, to distinguish mutliple MariaDB endpoints or databases, then you could use:

dbSpan.setServiceTarget('mariadb', 'mydb')

which should result in a "mariadb/mydb" node in the ServiceMap.