Investigate inaccuracies with r2dbc-postgresql

[meiao]

Description

When a connection is created, it makes some queries on which the instrumentation starts a segment but fails to end it.

This causes the transaction to last longer until the segment times out, making the time measurements inaccurate.

All versions of the instrumentation are affected by this.

[workato-integration]

https://new-relic.atlassian.net/browse/NR-172086

[meiao]

When a new connection is created, a query (not requested by the code) is executed. But for some reason, the doFinally in the request wrapper is not being executed:

    public static Flux<PostgresqlResult> wrapRequest(Flux<PostgresqlResult> request, ...) {
        //...
                Segment segment = transaction.startSegment("execute");
                return request
                        .doOnSubscribe(reportExecution(sql, connectionConfiguration, segment))
                        .doFinally((type) -> segment.end());
    }

newrelic-java-agent/instrumentation/r2dbc-postgresql-0.9.0/src/main/java/io/r2dbc/postgresql/R2dbcUtils.java

Line 26 in 624ff4c

.doFinally((type) -> segment.end());

This causes every transaction with a new connection to be held until the segment times out. Also since the segment was not ended, the whole time of the segment shows up in the transaction.

When a transaction uses a connection created outside of it, for instance as part of a connection pool, then this inaccuracy will not happen.