Concurrent reactive queries return the result to the wrong caller

[alessandrolulli]

Dear,

version:
quarkus: 3.21.0
smallrye-mutiny-vertx-sql-client: 3.18.1

We are using io.vertx.pgclient reactive. When executing multiple queries to the same pool concurrently sometimes the RowSet is returned to the wrong caller (i.e. we perform a query and we receive the result of another query).

This is the snippet of the code:
`
public Uni<List> getStatusChangeCount(long agentId) {
StringBuilder queryBuilder = new StringBuilder("SELECT device_id, count FROM table_with_count_1 WHERE agent_id = $1");
List params = new ArrayList<>();
params.add(agentId);

    String query = queryBuilder.toString();
    logger.debugf("Query: %s", query);

    return client
            .preparedQuery(query)
            .execute(Tuple.from(params))
            .map(rows -> {
                List<DeviceCountOutDto> events = new ArrayList<>();
                for (Row row : rows) {
                    DeviceCountOutDto event = new DeviceCountOutDto(
                            row.getLong("device_id"),
                            row.getInteger("count")
                    );
                    events.add(event);
                }
                return events;
            });
}

`

The client is:
@Inject @ReactiveDataSource("timescale") private Pool client;

We have another method executing another query with 3 columns and we get the following errors:
[20250423 12:10:51 DEBUG (AbstractResteasyReactiveContext.java:328) de302c86-dac2-4289-8b33-4769117f8785] - Attempting to handle unrecoverable exception: io.vertx.pgclient.PgException: ERROR: bind message has 3 result formats but query has 2 columns (08P01) [20250423 12:10:51 DEBUG (null:-1) de302c86-dac2-4289-8b33-4769117f8785] - RoutingContext failure (500): io.vertx.pgclient.PgException: ERROR: bind message has 3 result formats but query has 2 columns (08P01)

We are calling the two methods from two different REST API calls simoultaneously and sometimes we have this error and other times no errors.

Could you please help us understand why the execute method sometimes return the wrong RowSet?
Thanks

[cescoffier]

It's expected that each connection is associated with one event loop, and thus, that event loop may differ from yours. In this case, you need to capture and switch back to your event loop.

[alessandrolulli]

could you please elaborate more on this?
according to the following documentation the code snippet is very similar:
https://quarkus.io/guides/reactive-sql-clients#prepared-queries

[tsegismont]

@alessandrolulli could you put together a small reproducer and share it on GitHub please? Thanks

[alessandrolulli]

@tsegismont thanks for the answer.
The code is exactly the one wrote in the first post. We have two methods copy and paste of it just working on two different tables.
In front of the two methods there are two GET rest calls making use of Quarkus 3.21.4 (updated now).

We cant reproduce in local environment while developing with a mac but it is quite consistent (40% of the calls) when running inside a single core docker container in our testing environment. When the two rest calls are called simultaneously the issue is happening frequently.

The two methods are inside an @ApplicationScoped class sharing the pool of connection against the database:
@Inject @ReactiveDataSource("timescale") private Pool client;

Thanks

[tsegismont]

Can you please:

• confirm the database timescale db
• paste the schema for the table

[alessandrolulli]

• timescale database 2.19.2

Schema:
CREATE VIEW table_with_count_1 AS SELECT agent_id, device_id, count(*) AS count FROM device_events WHERE event_type = 'MY_TYPE' AND NOW() - timestamp::timestamptz <= interval '24 hours' GROUP BY agent_id, device_id;
CREATE TABLE device_events ( agent_id BIGINT NOT NULL, device_id BIGINT NOT NULL, timestamp TIMESTAMPTZ NOT NULL, event_type EVENT_TYPE_ENUM NOT NULL );