DB_VERSION_MISMATCH error every day

Question

Every day when I run my test.pl program for the first time, I see this:
DbEnv::open: DB_VERSION_MISMATCH: Database environment version mismatch in test.pl,
line 35
The docs say that this error means "The version of the Berkeley DB library doesn't match the version that created the database environment". But I haven't changed my BDB XML installation.
If I delete all the files in my test database directory and reload my test data, everything is fine. I can run my test program again and again all day long. But when I come in next morning, I get the error! This is the code I'm using:
    my $ENVIRONMENT = 'test-env';
    my $ENV_FLAGS   = Db::DB_CREATE | Db::DB_INIT_LOCK | Db::DB_INIT_LOG
                        | Db::DB_INIT_MPOOL | Db::DB_INIT_TXN;
    my $env = new DbEnv;
    x eval { $env->open($ENVIRONMENT, $ENV_FLAGS, 0) };'x' is just a function that traps the exception. Line 35 is the line with the open() call.
Does anybody know what I'm doing wrong?
Thanks, Dave

Answer 1

Could your installation be picking up another version
— probably preexisting — of the Berkeley DB libs?Good thought. I've done some digging.
There are two versions of Berkeley DB already installed on my system, according to YaST: 4.3.27-3.1 and 1.85-89. I don't want to interfere with those because I don't know what might be using them. Then there's the version which came with the dbxml I downloaded: 4.3.29, which is presently under /opt/berkeley
I seem to be picking up 4.3.29. When I run /opt/berkeley/bin/db_verify -V it says "Sleepycat Software: Berkeley DB 4.3.29: (September 6, 2005)". While if I run /usr/bin/db_verify -V it says "Sleepycat Software: Berkeley DB 4.3.27: (June 1, 2005)" but both are supposedly compatible with the current dbxml release, according to the release notes.
If I run /opt/berkeley/bin/dbxml -h test-env-old (i.e. using yesterday's data) it says
Program version 4.3 doesn't match environment version
Error opening environment test-env-old: DbEnv::open:
DB_VERSION_MISMATCH: Database environment version mismatchbut rather annoyingly doesn't tell me what version it thinks the data is!!!
dbxml is happy with a new test-env database that I've created today in Perl.
I haven't found any way to find out what version the data in test-env-old thinks it is. Is there some utility that will do this? I tried looking in the files but didn't spot anything.
That dbxml behaves the same as my test program seems to eliminate some Perl artefact as the source of this problem but in case it's useful to you or some Sleepycat person, I added a call to DbXml::printVersionInfo() to my test program, which duly reports:
perl  : 5.008006
dbxml : Sleepycat Software: Berkeley DB XML 2.2.13: (December 19, 2005)
db    : Sleepycat Software: Berkeley DB 4.3.29: (September  6, 2005)
xerces: whateverso it seems to be finding the right db library.
I've seen that happen elsewhere. Usually it results
in a library compatibility error though, rather than
a database version error.Any other ideas? I really appreciate all the help you're giving me.
This is a minor nuisance while I'm testing, but it's a complete showstopper for using dbxml in production, of course.