dbeng12 startup hang on osx

[Former Member]

Folks,

We have an intermittent hang starting dbeng12 via the capi on OSX. It is not 100% repeatable but affects our automated integration tests fairly frequently.

It does not happen with the same tests running on windows.

Is there any way to get any diagnostic information out of the dbeng12 process to try and narrow down why it is hanging?

Cheers, Dan

[jeff_albion]

When you start the process, do you include a console output file (dbeng12 -o console.txt)? If so, does the file get created at all, or does the process just fail to start entirely? If the file is created, what is reported before it "hangs"? If it doesn't get created, can you see the process attempting to start in "Activity Monitor"?

If we can't figure out the problem from that output, we can work directly with you to capture a core file of the process and bring it in for analysis to see if this would help explain what's happening inside the server: http://www.sybase.com/contactus/support/

[Former Member]

Thanks Jeff,

Because we are starting the server via the capi we can't specify the -o argument to the executable. Following your suggestion though we've added the LOG=<file> to the connection string... and since then it hasn't hung... So I'm going to monitor it for now until I get another hang and then I'll see what is in the log output from dbeng12...

Cheers, Dan

[Former Member · Accepted solution]

So, we finally seem to have reached the bottom of this issue and I thought I'd document it in case anyone else ran into it.

Basically, the issue is that the dynamic library load call we were using has some undesirable behaviour in the debugger when used with a particular flag. In the samples provided with the dbcapi the load library call is as follows:

handle = dlopen(name, RTLD_LAZY);

This is the recommended way of calling this function however there are some potential issues with debugging as documented here: http://tldp.org/HOWTO/Program-Library-HOWTO/dl-libraries.html

So we changed the code to: handle = dlopen(name, RTLD_NOW);

Which gets us past the problems documented above.

Thanks to all for help/suggestions.

Cheers, Dan