Problems connecting to server

[alzeha]

Hi,

my name is Alexander, I'm a PhD student at TU Darmstadt/Germany.

Am I the only one, having trouble setting up a remote verification server?

I want to use my desktop (running linux mint) as remote server. I run (via ssh):

# reboot
$ cd /path/to/uppaal64-4.1.26-1/bin-Linux/
$ ./socketserver
UPPAAL Socket Server
Copyright (c) 1995 - 2000, Aalborg University and Uppsala University
All rights reserved.
Listening on port 2350

I tried from both, archlinux and windows, to locally run uppaal and connect to the server. E.g. at windows I run:

uppaal64-4.1.26-1> java -jar .\uppaal.jar --serverHost <loc_ip> --serverPort 2350

An error window pops up:

Unknown protocol version: error
Java version: 11.0.15
Java vendor: Microsoft
JVM version: 11.0.15+10-LTS
JVM vendor: Microsoft
JVM name: OpenJDK 64-Bit Server VM
JRE version: 11
JRE vendor: Oracle Corporation
JRE name: Java Platform API Specification
OS name: Windows 10
OS arch: amd64

at server side:

Connection from <laptop> accepted
Connection from <laptop> closed

after clicking "ok", uppaal opens anyway. But starting a verification is not possible. A window opens, asking for a License installation (??? i never read about sth like this?).

This happens also when I start the socketserver as sudo.

Is there anywhere a more clear tutorial, regarding the question what i have to do to start a remote server? I don't get whats happening here.

Sorry for the inconvenience.

Best regards,
Alexander

[RasmusRendal]

Hello Alexander. Could you try running the socketserver with the arguments -dm, as in ./socketserver -dm, and then sending the output? This should output a server trace, which should be helpful in troubleshooting.

[alzeha]

Hi,

thanks for your answer!

The result is

Caught signal 17, closing proxy.
1697: ERROR /usr/bin/env: symbol lookup error: path/to/uppaal64-4.1.26-1/bin-Linux/libc.so.6: undefined symbol: _dl_catch_error_ptr, version GLIBC_PRIVATE

huh, so you're trying to statically link against a shipped libc, right? Is this really a good idea?

Something is breaking at this point... I'm unsure what exactly the problem is.

[mikucionisaau]

Caught signal 17, closing proxy. 1697: ERROR /usr/bin/env: symbol lookup error: path/to/uppaal64-4.1.26-1/bin-Linux/libc.so.6: undefined symbol: _dl_catch_error_ptr, version GLIBC_PRIVATE

huh, so you're trying to statically link against a shipped libc, right? Is this really a good idea?

It's dynamic linking. I suspect that the libc on your system is newer, thus the shell wrapper fails to run /usr/bin/env with the libc from Uppaal.

Could you try running the socketserver and the server directly with your libc? i.e.:

./socketserver.bin -s ./server.bin

If the above works, you can just overwrite the shell wrappers with the binaries, like this:

mv server.bin server
mv socketserver.bin socketserver

[alzeha]

same problem:

$ ./socketserver.bin -s ./server.bin
./socketserver.bin: symbol lookup error: /path/to/uppaal64-4.1.26-1/bin-Linux/libc.so.6: undefined symbol: _dl_catch_error_ptr, version GLIBC_PRIVATE

[RasmusRendal]

Did you try socat as described further down?

[RasmusRendal]

So what is happening is that socketserver is running with the included linker and LD_LIBRARY_PATH, which we include to make sure that our distribution works on pretty much anything.

However, what the socketserver does is simply running ./server in a loop and serving it over port 2350. But in this case ./server is a shell script, which uses /usr/bin/env from your system, which isn't compatible with the included linker and LD_LIBRARY_PATH, resulting in the error. Fixing the socketserver might turn out to be a bit an ordeal, so until that is fixed, you can use socat instead of the socketserver as a workaround:

socat TCP-LISTEN:2350,reuseaddr,fork EXEC:"./server"

You might have to install it using apt: sudo apt install socat should do the trick.

[alzeha]

Thats working, thanks!

[mikucionisaau]

@alzeha I am glad this worked for you.
Could you please tell us the libc version on your computer? It can be displayed by the following command:

dpkg -l libc6

[alzeha]

sure.

$ dpkg -l libc6

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version         Architecture Description
+++-==============-===============-============-=================================
ii  libc6:amd64    2.31-0ubuntu9.9 amd64        GNU C Library: Shared libraries
ii  libc6:i386     2.31-0ubuntu9.9 i386         GNU C Library: Shared libraries