hanging imapd process

[Gerhard Rechel]

After upgrade from Cyrus-IMAP 2.2.12 to 2.2.13 we have a problem with 
hanging imapd-processess. This happens about once a day on our production 
system.

in TOP the process uses ca. 98% CPU and  strace shows following:
--- SIGSTOP (Stopped (signal)) @ 0 (0) ---
--- SIGSTOP (Stopped (signal)) @ 0 (0) ---
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
59) = 0
write(1, "&\234\320+\252~\207\257\274s\316C\247e\266\356\275\"\377"..., 42949672
o59) = 0
...

Any ideas are welcome!
Our Configuration:
name       : Cyrus IMAPD
version    : v2.2.13 2006/03/30 16:00:03
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.6.8-3-686-smp
environment: Built w/Cyrus SASL 2.1.20
              Running w/Cyrus SASL 2.1.20
              Built w/Sleepycat Software: Berkeley DB 4.2.52: (December  3, 2003)
              Running w/Sleepycat Software: Berkeley DB 4.2.52: (December  3, 200
3)
              Built w/OpenSSL 0.9.8 05 Jul 2005
              Running w/OpenSSL 0.9.8 05 Jul 2005
              CMU Sieve 2.2
              TCP Wrappers
              mmap = shared
              lock = fcntl
              nonblock = fcntl
              idle = polla

cyrus.conf:
# standard standalone server implementation

START {
   # do not delete this entry!
   recover       cmd="ctl_cyrusdb -r"

   # this is only necessary if using idled for IMAP IDLE
#  idled                cmd="idled"
}

# UNIX sockets start with a slash and are put into /var/imap/socket
SERVICES {
   # add or remove based on preferences
   imap          cmd="imapd" listen="imap" prefork=0
   imaps         cmd="imapd -s" listen="imaps" prefork=0
   pop3          cmd="pop3d" listen="pop3" prefork=0
   pop3s         cmd="pop3d -s" listen="pop3s" prefork=0
   sieve         cmd="timsieved" listen="sieve" prefork=0

   # smmapd Daemon for unknown user RRZN
   smmapd        cmd="smmapd" listen="/var/imap/socket/smmapd" prefork=1

   # at least one LMTP is required for delivery
#  lmtp         cmd="lmtpd" listen="lmtp" prefork=0
   lmtpunix      cmd="lmtpd" listen="/var/imap/socket/lmtp" prefork=0

# this is only necessary if using notifications
#  notify       cmd="notifyd" listen="/var/imap/socket/notify" proto="udp" prefo
rk=1
}

EVENTS {
   # this is required
   checkpoint    cmd="ctl_cyrusdb -c" period=30

   # this is only necessary if using duplicate delivery suppression
          delprune     cmd="cyr_expire -E 3" at=0400

   # this is only necessary if caching TLS sessions
   tlsprune      cmd="tls_prune" at=0400
# create an index for mailboxes
   squatter      cmd="squatter -s" at=0300
}

imapd.conf:
configdirectory: /var/imap
admins: cyrus zzismail
altnamespace: yes
annotation_db: skiplist
defaultacl: anyone lrs
defaultdomain: uni-hannover.de
defaultpartition: default
duplicate_db: skiplist
duplicatesuppression: yes
fulldirhash: yes
idlesocket: /var/imap/socket/idle
implicit_owner_rights: lca
lmtpsocket: /var/imap/socket/lmtp
lmtp_downcase_rcpt: yes
maxmessagesize: 0
mboxlist_db: skiplist
notifysocket: /var/imap/socket/notify
partition-default: /disk/imap
popminpoll: 1
poppollpadding: 2
postuser: bxb
quota_db: quotalegacy
quotawarn: 80
sasl_pwcheck_method: saslauthd
sasl_mech_list: plain login
seenstate_db: skiplist
sieve_maxscriptsize: 512
sieveusehomedir: false
sievedir: /disk/sieve
tls_cert_file:/var/imap/server-crt.pem 
tls_key_file:/var/imap/server-key.pem
tls_ca_file:/var/imap/cacert.pem
username_tolower: yes
unix_group_enable: no
#virtdomains: on
virtdomains: userid
# allowplaintext: yes
# 01name: rrzn.uni-hannover.de
# timeout: 30
# sharedprefix:
# defaultacl: l
unixhierarchysep: yes


Gerhard Rechel
Regionales Rechenzentrum Universitaet Hannover
Schlosswender Str. 5

rechel at rrzn.uni-hannover.de - 0511/762-3365