Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.reactive.function.client.WebClientRequestException: Error while acquiring from reactor.netty.internal.shaded.reactor.pool.SimpleDequePool@4e699e; nested exception is java.io.IOException: Error while acquiring from reactor.netty.internal.shaded.reactor.pool.SimpleDequePool@4e699e] with root cause

java.io.IOException: Error while acquiring from reactor.netty.internal.shaded.reactor.pool.SimpleDequePool@4e699e
	at reactor.netty.resources.DefaultPooledConnectionProvider$DisposableAcquire.run(DefaultPooledConnectionProvider.java:239)
	at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
	at io.netty.util.concurrent.PromiseTask.run(PromiseTask.java:106)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:384)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:832)

        Mono<Object> mono = webClient.get()
            .uri(uriBuilder -> {
                uriBuilder.scheme(coreApiBaseUri.getScheme())
                    .host(coreApiBaseUri.getHost())
                    .port(coreApiBaseUri.getPort())
                    .pathSegment(versionPath, "projects", "{id}", "series");

                return uriBuilder.build(projectId);
            })
            .headers(httpHeaders -> httpHeaders.addAll(incomingHeaders))
            .exchangeToMono(clientResponse -> {
                HttpStatus httpStatus = clientResponse.statusCode();
                if (httpStatus.isError()) {
                    if (httpStatus != HttpStatus.BAD_REQUEST) {
                        log.warn("Received status {} from core-api while getting series", httpStatus);
                    }
                    return clientResponse.bodyToMono(ErrorDTO.class);
                }
                return clientResponse.bodyToMono(CoreApiSeriesDTO.class);
            })
            .timeout(Duration.ofMillis(1000))
            .retryWhen(retryOnConnectionErrorsOr5xx("Retrying getting series for project {}, attempt {}", projectId));

        Object dto = mono.block();
        if (dto == null) {
            throw new InternalException(String.format("No/invalid result for project id %s", projectId));
        }

    private Retry retryOnConnectionErrorsOr5xx(String logString, UUID logStringParam1) {
        return Retry
            .fixedDelay(3, Duration.ofSeconds(1L))
            .filter(exception -> exception instanceof IOException
                || exception instanceof TimeoutException
                || exception instanceof WebClientResponseException
                && ((WebClientResponseException) exception).getStatusCode().is5xxServerError())
            .doBeforeRetry(retrySignal -> {
                log.info(logString, logStringParam1, retrySignal.totalRetries());
                log.debug("Exception in retry: ", retrySignal.failure());
            });
    }