WARN [ProxiedResource] dont understand

[Corentin]

Hello,

i got that log :

2018-06-12T10:52:12.333+02:00 WARN  [ProxiedResource] Unable to call https://192.168.10.1:9000/api/system on node <c910ac4e-778c-4485-bcda-3aa3f93a0580>
java.net.SocketTimeoutException: timeout
        at okio.Okio$4.newTimeoutException(Okio.java:230) ~[graylog.jar:?]
        at okio.AsyncTimeout.exit(AsyncTimeout.java:285) ~[graylog.jar:?]
        at okio.AsyncTimeout$2.read(AsyncTimeout.java:241) ~[graylog.jar:?]
        at okio.RealBufferedSource.indexOf(RealBufferedSource.java:345) ~[graylog.jar:?]
        at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:217) ~[graylog.jar:?]
        at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:211) ~[graylog.jar:?]
        at okhttp3.internal.http1.Http1Codec.readResponseHeaders(Http1Codec.java:187) ~[graylog.jar:?]
        at okhttp3.internal.http.CallServerInterceptor.intercept(CallServerInterceptor.java:88) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:45) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) ~[graylog.jar:?]
        at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) ~[graylog.jar:?]
        at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:125) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) ~[graylog.jar:?]
        at org.graylog2.rest.RemoteInterfaceProvider.lambda$get$0(RemoteInterfaceProvider.java:59) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) ~[graylog.jar:?]
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) ~[graylog.jar:?]
        at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:200) ~[graylog.jar:?]
        at okhttp3.RealCall.execute(RealCall.java:77) ~[graylog.jar:?]
        at retrofit2.OkHttpCall.execute(OkHttpCall.java:180) ~[graylog.jar:?]
        at org.graylog2.shared.rest.resources.ProxiedResource.lambda$getForAllNodes$0(ProxiedResource.java:76) ~[graylog.jar:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_161]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_161]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_161]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_161]
Caused by: java.net.SocketException: Socket closed
        at java.net.SocketInputStream.read(SocketInputStream.java:204) ~[?:1.8.0_161]
        at java.net.SocketInputStream.read(SocketInputStream.java:141) ~[?:1.8.0_161]
        at sun.security.ssl.InputRecord.readFully(InputRecord.java:465) ~[?:1.8.0_161]
        at sun.security.ssl.InputRecord.read(InputRecord.java:503) ~[?:1.8.0_161]
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:983) ~[?:1.8.0_161]
        at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:940) ~[?:1.8.0_161]
        at sun.security.ssl.AppInputStream.read(AppInputStream.java:105) ~[?:1.8.0_161]
        at okio.Okio$2.read(Okio.java:139) ~[graylog.jar:?]
        at okio.AsyncTimeout$2.read(AsyncTimeout.java:237) ~[graylog.jar:?]

message error on web interface :

When I restart the server I do not have more error and I can access https://192.168.10.1:9000/system/nodes but if I just restart only the service graylog. this warning message appears on my log and i cant access to https://192.168.10.1:9000/system/nodes

I got one node and i dont use reverse proxy or and load balancer