Connection Pool creates many connection attempts if all connection attempts fail

• Driver: io.r2dbc:r2dbc-postgresql:0.8.2.RELEASE and r2dbc-pool:0.8.2.RELEASE
• Database: POSTGRES
• Java: 11
• OS: Linux

Current Behavior

Because of a Vault error, credentials generated for Postgres will be wrong. What happens is that the application will try thousands of times to reconnect to the DB, filling the DB logs. I don’t know by what component this is cause, this happened several days ago and I don’t have full logs. What I have is just this stacktrace (only for the http part):

i.r.p.ExceptionFactory$PostgresqlAuthenticationFailure: password authentication failed for user \"v-approle-readwrit-3524s732v0xv72tqv0vx-1595235650\"\n\tat i.r.p.ExceptionFactory.createException(ExceptionFactory.java:74)\n\tat i.r.p.ExceptionFactory.handleErrorResponse(ExceptionFactory.java:110)\n\tat r.c.p.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:96)\n\tat r.c.p.FluxHandle$HandleConditionalSubscriber.onNext(FluxHandle.java:319)\n\tat r.c.p.FluxCreate$BufferAsyncSink.drain(FluxCreate.java:793)\n\tat r.c.p.FluxCreate$BufferAsyncSink.next(FluxCreate.java:718)\n\tat r.c.p.FluxCreate$SerializedSink.next(FluxCreate.java:153)\n\tat i.r.p.c.ReactorNettyClient$Conversation.emit(ReactorNettyClient.java:679)\n\tat i.r.p.c.ReactorNettyClient$BackendMessageSubscriber.emit(ReactorNettyClient.java:867)\n\tat i.r.p.c.ReactorNettyClient$BackendMessageSubscriber.onNext(ReactorNettyClient.java:801)\n\tat i.r.p.c.ReactorNettyClient$BackendMessageSubscriber.onNext(ReactorNettyClient.java:710)\n\tat r.c.p.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:112)\n\tat r.c.p.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:845)\n\tat r.c.p.FluxMap$MapConditionalSubscriber.onNext(FluxMap.java:213)\n\tat r.c.p.FluxMap$MapConditionalSubscriber.onNext(FluxMap.java:213)\n\tat r.n.c.FluxReceive.drainReceiver(FluxReceive.java:218)\n\tat r.n.c.FluxReceive.onInboundNext(FluxReceive.java:351)\n\tat r.n.c.ChannelOperations.onInboundNext(ChannelOperations.java:348)\n\tat r.n.c.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:90)\n\tat i.n.c.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)\n\tat i.n.c.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)\n\tat i.n.c.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355)\n\tat i.n.h.c.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321)\n\tat i.n.h.c.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:295)\n\tat i.n.c.AbstractChannelHandlerContext.invokeChannelRead(Abstract...

the result of continous retries was to fill up RDS instances disks with the Logs.

I had a peek in the code but can’t really find the issue, would be great to have some help.

config is:

    public ConnectionFactory connectionFactory() {
        var postgresqlConnectionConfiguration = getPostgresConfiguration();

        var postgresqlConnectionFactory = new PostgresqlConnectionFactory(postgresqlConnectionConfiguration);

        var poolFactoryConfiguration = ConnectionPoolConfiguration.builder(postgresqlConnectionFactory)
                .maxIdleTime(Duration.ofMillis(1000))
                .maxSize(20)
                .build();
        var pooledConnectionFactory = new ConnectionPool(poolFactoryConfiguration);
        return pooledConnectionFactory;
    }

    protected PostgresqlConnectionConfiguration getPostgresConfiguration() {
        return PostgresqlConnectionConfiguration.builder()
                .host(dbProperties.getHost())
                .port(dbProperties.getPort())
                .username(dbProperties.getUsername())
                .password(dbProperties.getPassword())
                .database(dbProperties.getDatabase())
                .build();
    }

[mp911de]

I’d close this ticket now unless there’s an objection to keeping it open.

[simonbasle]

I think your analysis is correct @mp911de. the pool tries to enforce the minimum size by warming up each time there is an attempt at acquiring which detects the pool is undersized.