Webclient SslHandshakeTimeoutException: handshake timed out after 10000ms - spring-boot

Question

I've recently made a component using webflux and webclient.
There are a few requests that uses an external resource to retrieve some data.
In local works everything fine, retrieving data from the external resource and correctly displays to the user.
When i do a deploy on remote server it doesn't work anymore and it shows me these error:
i.n.r.DefaultHostsFileEntriesResolver : -Dio.netty.hostsFileRefreshInterval: 0
Jan 08 23:59:31 dlv-izac-user app/web.1 2023-01-09 07:59:30.715 DEBUG 4 --- [or-http-epoll-7] i.n.util.ResourceLeakDetectorFactory : Loaded default ResourceLeakDetector: io.netty.util.ResourceLeakDetector#5abf28c7
Jan 08 23:59:31 dlv-izac-user app/web.1 2023-01-09 07:59:30.717 DEBUG 4 --- [or-http-epoll-7] io.netty.resolver.dns.DnsQueryContext : [id: 0x477cca20] WRITE: UDP, [45834: /10.1.0.2:53], DefaultDnsQuestion(izac-dlv.herokuapp.com. IN A)
Jan 08 23:59:31 dlv-izac-user app/web.1 2023-01-09 07:59:30.722 WARN 4 --- [or-http-epoll-7] io.netty.channel.epoll.EpollEventLoop : Unexpected exception in the selector loop.
Jan 08 23:59:31 dlv-izac-user app/web.1 io.netty.channel.unix.Errors$NativeIoException: epoll_wait(..) failed: Function not implemented
Jan 08 23:59:32 dlv-izac-user app/web.1 2023-01-09 07:59:31.722 WARN 4 --- [or-http-epoll-7] io.netty.channel.epoll.EpollEventLoop : Unexpected exception in the selector loop.
Jan 08 23:59:32 dlv-izac-user app/web.1 io.netty.channel.unix.Errors$NativeIoException: epoll_wait(..) failed: Function not implemented
Jan 08 23:59:33 dlv-izac-user app/web.1 2023-01-09 07:59:32.723 WARN 4 --- [or-http-epoll-7] io.netty.channel.epoll.EpollEventLoop : Unexpected exception in the selector loop.
Jan 08 23:59:33 dlv-izac-user app/web.1 io.netty.channel.unix.Errors$NativeIoException: epoll_wait(..) failed: Function not implemented
Jan 08 23:59:34 dlv-izac-user app/web.1 2023-01-09 07:59:33.723 WARN 4 --- [or-http-epoll-7] io.netty.channel.epoll.EpollEventLoop : Unexpected exception in the selector loop.
Jan 08 23:59:34 dlv-izac-user app/web.1 io.netty.channel.unix.Errors$NativeIoException: epoll_wait(..) failed: Function not implemented
Jan 08 23:59:35 dlv-izac-user app/web.1 2023-01-09 07:59:34.724 WARN 4 --- [or-http-epoll-7] io.netty.channel.epoll.EpollEventLoop : Unexpected exception in the selector loop.
Jan 08 23:59:35 dlv-izac-user app/web.1 io.netty.channel.unix.Errors$NativeIoException: epoll_wait(..) failed: Function not implemented
Jan 08 23:59:36 dlv-izac-user app/web.1 2023-01-09 07:59:35.734 DEBUG 4 --- [or-http-epoll-7] io.netty.resolver.dns.DnsNameResolver : [id: 0x477cca20] RECEIVED: UDP [45834: /10.1.0.2:53], DatagramDnsResponse(from: /10.1.0.2:53, 45834, QUERY(0), NoError(0), RD RA)
Jan 08 23:59:36 dlv-izac-user app/web.1 DefaultDnsQuestion(izac-dlv.herokuapp.com. IN A)
Jan 08 23:59:36 dlv-izac-user app/web.1 DefaultDnsRawRecord(izac-dlv.herokuapp.com. 9 IN A 4B)
Jan 08 23:59:36 dlv-izac-user app/web.1 DefaultDnsRawRecord(izac-dlv.herokuapp.com. 9 IN A 4B)
Jan 08 23:59:36 dlv-izac-user app/web.1 DefaultDnsRawRecord(izac-dlv.herokuapp.com. 9 IN A 4B)
Jan 08 23:59:36 dlv-izac-user app/web.1 DefaultDnsRawRecord(OPT flags:0 udp:4096 0B)
Jan 09 00:00:16 dlv-izac-user app/web.1 2023-01-09 08:00:15.814 WARN 4 --- [or-http-epoll-8] r.netty.http.client.HttpClientConnect : [fc253c96, L:/172.19.105.50:34258 - R:izac-dlv.herokuapp.com/46.137.15.86:443] The connection observed an error
Jan 09 00:00:16 dlv-izac-user app/web.1 io.netty.handler.ssl.SslHandshakeTimeoutException: handshake timed out after 10000ms
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.handler.ssl.SslHandler$7.run(SslHandler.java:2113) ~[netty-handler-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:170) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:391) ~[netty-transport-classes-epoll-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.76.Final.jar!/:4.1.76.Final]
Jan 09 00:00:16 dlv-izac-user app/web.1 at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]
This is my call using webClient
URI uri = UriComponentsBuilder.fromHttpUrl(izacComponentUrl)
.queryParam("request", request)
.build().toUri();
WebClient client = WebClient.builder()
.defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
.build();
return client.get()
.uri(uri)
.retrieve()
.bodyToFlux(RestaurantInfoResponseBody.class)
.onErrorContinue(RuntimeException.class, (ex, o) -> log.error("Errore durante il recupero dei dati tramite il servizio esterno!"));
}

Answer 1

You have a timeout.
Have you checked if the network flow is open between the 2 servers ?