Possible network issue

[Alan Bateman]

On 07/11/2023 06:32, robert engels wrote:
> Hi,
>
> I would ordinarily send this to the net list, but I think this code was changed to support VT - using Nio behind the scenes for socket writes.
>
> Essentially, I am receiving the following exception under heavy load (exhausting the kernel network buffers):
>
> java.net.SocketException: No buffer space available
>          at java.base/sun.nio.ch.SocketDispatcher.write0(Native Method)
>          at java.base/sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:62)
>          at java.base/sun.nio.ch.NioSocketImpl.tryWrite(NioSocketImpl.java:394)
>          at java.base/sun.nio.ch.NioSocketImpl.implWrite(NioSocketImpl.java:410)
>          at java.base/sun.nio.ch.NioSocketImpl.write(NioSocketImpl.java:440)
>          at java.base/sun.nio.ch.NioSocketImpl$2.write(NioSocketImpl.java:819)
>          at java.base/java.net.Socket$SocketOutputStream.write(Socket.java:1195)
>          at robaho.net.httpserver.HttpConnection$ActivityTimerOutputStream.write(HttpConnection.java:189)

Is this macos-aarch64? I don't think we've seen this with virtual 
threads but there are dozen or more issues in JBS on this same issue 
where is happens elsewhere, JDK-8273158 [1] is one example. A lot of 
data has been collected but I don't think there is a conclusion yet on 
whether this resource exhaustion issue is real or not. At one point I 
thought we were close enough to having enough to report a bug to Apple 
or ask for tuning advice.

-Alan

[1] https://bugs.openjdk.org/browse/JDK-8273158