RFR: 8350545: Several sun/management/jdp tests fails java.net.SocketException

[SendaoYan]

On Sun, 23 Feb 2025 13:31:00 GMT, SendaoYan <syan at openjdk.org> wrote:

>> test/jdk/sun/management/jdp/DynamicLauncher.java line 66:
>> 
>>> 64:         if (output.contains("java.net.SocketException: No such device")) {
>>> 65:             throw new SkippedException("Network setup issue, skip this test");
>>> 66:         }
>> 
>> Something else isn't right if you are getting this error so I think further investigation is required to see if the issue is the test choosing the wrong interface or address, or a configuration issue on the test system.
>
> The tested address:port is hard code to '224.0.23.178:7095' by file test/jdk/sun/management/jdp/ClientConnection.java. This address:port work normally on most machines, but cannot work on machine which can not connect to the internet directly.

Seems that the exception from src/java.base/unix/native/libnio/ch/Net.c:679.
I'm not familiar with jdp feature, Could you give me some advices how to make check is the test choosing the wrong interface or address.

The information test system which report test failure shows below:


> ifconfig 
enP2p129s0f1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.50.12  netmask 255.255.255.0  broadcast 192.168.50.255
        inet6 fe80::1163:1d10:87a:6be4  prefixlen 64  scopeid 0x20<link>
        ether a0:36:9f:53:17:f6  txqueuelen 1000  (Ethernet)
        RX packets 22678271  bytes 28824464370 (26.8 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9400465  bytes 7501254087 (6.9 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 26485240  bytes 221859212049 (206.6 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 26485240  bytes 221859212049 (206.6 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

> ip r
192.168.50.0/24 dev enP2p129s0f1 proto kernel scope link src 192.168.50.12 metric 100 


Command wget shows that it should connect internet through a jumper machine(192.168.50.1:10991):


> wget www.bing.com
--2025-02-24 17:56:25--  http://www.bing.com/
Connecting to 192.168.50.1:10991... connected.
Proxy request sent, awaiting response... 301 Moved Permanently
Location: http://cn.bing.com/ [following]
--2025-02-24 17:56:25--  http://cn.bing.com/
Reusing existing connection to 192.168.50.1:10991.
Proxy request sent, awaiting response... 200 OK
Length: 13006 (13K) [text/html]
Saving to: ‘index.html’

index.html                                        100%[=============================================================================================================>]  12.70K  --.-KB/s    in 0s      

2025-02-24 17:56:25 (28.7 MB/s) - ‘index.html’ saved [13006/13006]

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PR Review Comment: https://git.openjdk.org/jdk/pull/23738#discussion_r1967322056