2.2cvs, imapd OK, pop3d hangs before sending banner to clients

[Jonathan Marsden]

On one of our (Red Hat 7.3, dual PIII CPU) servers running cyrus-imapd
(2.2 CVS as of late September 2002), last night POP3 and POP3S access
mysteriously "stopped working".  IMAP and IMAPS access are still fine.

Looking at the logs shows things like:

Jan 10 02:11:16 aerogram pop3s[17907]: DBERROR db4: 459 lockers

Which is, shall we say, unusual.  Since October we have seen only very
small numbers of "lockers" in these messages.  This server has only
some tens of email users at present.  Only the duplicate and tls db's
use berkeley.

Attempting to access the server via POP3 gets a connect and then
nothing.  Access via pop3s gets a connect, the full SSL handshake
sequence, then nothing.

Restarting cyrus-imapd did not help.

cyradm version output is:

name       : Cyrus IMAPD
version    : v2.2.prealpha-GRC-RPM-2.2-cvs.20020926 2002/09/26 19:19:16
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.4.18-17.7.xsmp
environment: Built w/Cyrus SASL 2.1.7
             Running w/Cyrus SASL 2.1.10
             Sleepycat Software: Berkeley DB 4.0.14: (November 18, 2001)
             OpenSSL 0.9.6b [engine] 9 Jul 2001
             CMU Sieve 2.2
             TCP Wrappers
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             auth = unix
             idle = poll
             mboxlist.db = skiplist
             subs.db = flat
             seen.db = skiplist
             duplicate.db = berkeley-nosync
             tls.db = berkeley-nosync

We had upgraded cyrus-sasl to 2.1.10, but downgrading back to 2.1.7
did not change this issue.

Attaching to one 'connected to but hung' pop3d with gdb shows a
backtrace of:

    (gdb) bt
    #0  0x420dadf4 in read () from /lib/i686/libc.so.6
    #1  0x4002a480 in __DTOR_END__ () from /usr/lib/libsasl2.so.2
    #2  0x40024186 in randinit () from /usr/lib/libsasl2.so.2
    #3  0x400241cd in sasl_rand () from /usr/lib/libsasl2.so.2
    #4  0x40023e3f in sasl_mkchal () from /usr/lib/libsasl2.so.2
    #5  0x0804cccb in service_main ()
    #6  0x0805149b in main ()
    #7  0x42017589 in __libc_start_main () from /lib/i686/libc.so.6
    (gdb) 

How can I best troubleshoot this further -- or is a quick fix already
known?

Thanks,

Jonathan
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