dovecot - Apr 2014 - FTS Lucene: Fatal: master: service(indexer-worker): child * killed with signal 6

Hi List,

Since we migrated from dovecot 1.2.4 to 2.2.12 with lucene as FTS 
engine, I have this in my error log:

Apr 22 14:01:14 indexer-worker(username): Error: lucene index 
/var/vmail/username/lucene-indexes: IndexWriter() failed (#1): Lock 
obtain timed out
Apr 22 14:01:14 indexer-worker: Error: indexer-worker 
[username at mydomain.com MailBox-1 - 20800/22707]: 
/home/anotherusername/newnew/clucene/src/core/CLucene/index/DocumentsWriter.cpp:210:
std::string lucene::index::DocumentsWriter::closeDocStore(): Assertion 
`numDocsInStore*8 == directory->fileLength( (docStoreSegment + "."
+
IndexFileNames::FIELDS_INDEX_EXTENSION).c_str() )' failed.
Apr 22 14:01:14 indexer: Error: Indexer worker disconnected, discarding 
1 requests for username at mydomain.com
Apr 22 14:01:14 indexer-worker(username at mydomain.com): Fatal: master: 
service(indexer-worker): child 31158 killed with signal 6 (core not dumped)
Apr 22 14:01:16 imap(username): Error: indexer failed to index mailbox 
MailBox-2

Does that sound familiar to someone ?

Thanks.


# 2.2.12: /usr/local/etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-431.11.2.el6.x86_64 x86_64 CentOS release 6.5 (Final) 
ext4
auth_cache_size = 10 M
auth_debug = yes
auth_master_user_separator = *
auth_socket_path = /var/run/dovecot/auth-userdb
auth_username_chars = 
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@*
auth_verbose = yes
auth_verbose_passwords = sha1
base_dir = /var/run/dovecot/
debug_log_path = /var/log/dovecot-debug.log
default_client_limit = 2128
default_process_limit = 512
default_vsz_limit = 2 G
hostname = mydomain.com
info_log_path = /var/log/dovecot.log
lda_mailbox_autocreate = yes
lda_mailbox_autosubscribe = yes
listen = *
log_path = /var/log/dovecot-error.log
login_greeting = Welcome
login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c
mail_debug = yes
mail_gid = vmail
mail_location = maildir:/var/vmail/%Ln
mail_plugins = fts fts_lucene quota stats
mail_uid = vmail
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date ihave
namespace {
   inbox = yes
   location = maildir:/var/vmail/%Ln
   mailbox Drafts {
     auto = subscribe
     special_use = \Drafts
   }
   mailbox Sent {
     auto = subscribe
     special_use = \Sent
   }
   mailbox Trash {
     auto = subscribe
     special_use = \Trash
   }
   prefix    type = private
}
passdb {
   args = /usr/local/etc/dovecot/deny-users
   deny = yes
   driver = passwd-file
}
passdb {
   args = /usr/local/etc/dovecot/master-users
   driver = passwd-file
   master = yes
}
passdb {
   args = /usr/local/etc/dovecot/dovecot-ldap.conf.ext
   driver = ldap
}
plugin {
   fts = lucene
   fts_autoindex = yes
   fts_autoindex_max_recent = 1000
   fts_lucene = whitespace_chars=@
   quota = maildir:User quota
   quota_rule = *:storage=20GB
   quota_rule2 = Trash:storage=+200M
   quota_warning = storage=95%% quota-warning 95 %u
   quota_warning2 = storage=80%% quota-warning 80 %u
   sieve = /var/sieve-scripts/%Ln.sieve
   sieve_dir = /var/vmail/%Ln/home/sieve
   stats_command_min_time = 1 mins
   stats_domain_min_time = 12 hours
   stats_ip_min_time = 12 hours
   stats_memory_limit = 16 M
   stats_refresh = 30 secs
   stats_session_min_time = 15 mins
   stats_track_cmds = yes
   stats_user_min_time = 1 hours
}
postmaster_address = postmaster at mydomain.com
protocols = imap pop3 sieve sieve
service auth-worker {
   user = root
}
service auth {
   unix_listener /var/spool/postfix/private/auth {
     mode = 0777
     user = vmail
   }
}
service decode2text {
   executable = script /usr/local/libexec/dovecot/decode2text.sh
   unix_listener decode2text {
     mode = 0666
   }
   user = dovecot
}
service imap-login {
   inet_listener imaps {
     port = 993
     ssl = yes
   }
   process_min_avail = 5
}
service imap {
   process_limit = 1024
}
service managesieve-login {
   inet_listener sieve {
     port = 4190
   }
}
service pop3-login {
   inet_listener pop3s {
     port = 995
     ssl = yes
   }
}
service quota-warning {
   executable = script /usr/local/bin/quota-warning.sh
   user = nobody
}
service stats {
   fifo_listener stats-mail {
     mode = 0600
     user = vmail
   }
}
ssl_cert = </etc/pki/tls/certs/mail.mydomain.com.pem
ssl_key = </etc/pki/tls/private/mail.mydomain.com.key
userdb {
   args = /usr/local/etc/dovecot/dovecot-ldap-userdb.conf.ext
   driver = ldap
   override_fields = uid=vmail gid=vmail home=/var/vmail/%Ln/home
}
verbose_proctitle = yes
protocol lda {
   mail_plugins = fts fts_lucene quota stats sieve virtual
}
protocol imap {
   mail_plugins = fts fts_lucene quota stats imap_quota virtual imap_stats
}