Hi all!
First of all, I want ti thank the whole Dovecot community (developers
for developing and fast responses, users for populating and responses
too). Dovecot is a really good and fast IMAP server - it serves near
3000 in our installation.
Now I have a problem and request community's help its resolving;)
Dovecot version: 1.0.13, compiled with vpopmail support.
I have an account spam at domain.com (:-), in which we put all our spam (we
gather statistic later). There can be 10 and more delivery attempts in a
second to maildir of this account during the spam attacks on our server.
The queue of our server can grow up to 20k messages, and all of these
messages are sent to spam at domain.com. I found a lot of such strings in
dovecot.log file during the such DoS attack:
dovecot.log:deliver(spam at domain.com): May 16 04:18:48 Info:
msgid=<01c8b6da$a8bacf80$b7af2abe at sale>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:18:59 Info:
msgid=<6611811842.20080516012444 at poiusadfhnvxzmdiasdasgkhlsdkfg.com>:
save failed to INBOX: Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:06 Info:
msgid=<01c8b6a8$7b552e00$a0a4034c at sale>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:14 Info:
msgid=<360825920.32055246029506 at mirgames.ru>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:50 Info:
msgid=<01c8b6b1$0df9cb00$cc36dfc9 at tek2>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:21:00 Info:
msgid=<087901c7ca2d$ef272640$1e01a8c0 at telefonia.InterCable.net>: save
failed to INBOX: Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:21:01 Info:
msgid=<000701c8b6d2$01ff999f$c491aca7 at snoueiij>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:32 Info:
msgid=<000801c8b69b$060c0230$3cd8a4b7 at cpbvlrx>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:45 Info:
msgid=<000801c8b6a5$04ba6412$9910848d at aldldr>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:45 Info:
msgid=<031401c772e2$adc5be40$1e01a8c0 at mtu-net.ru>: save failed to
INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:23:08 Info:
msgid=<01c8b6db$0222fe80$b7af2abe at info>: save failed to INBOX: Timeout
while waiting for lock
My dovecot.conf:
$ cat /etc/dovecot.conf | grep -v \# | grep -v ^\n
protocols = imap pop3
log_path = /var/log/dovecot.log
ssl_disable = yes
login_user = dovecot
login_process_per_connection = no
login_max_connections = 1024
login_greeting = Server is ready.
>>dotlock_use_excl = yes - can it be the reason?
fsync_disable = yes
first_valid_uid = 39
last_valid_uid = 39
first_valid_gid = 39
last_valid_gid = 39
max_mail_processes = 1024
maildir_copy_with_hardlinks = yes
maildir_copy_preserve_filename = yes
protocol imap {
mail_plugins = quota imap_quota
login_greeting_capability = yes
imap_client_workarounds = outlook-idle
}
protocol pop3 {
pop3_lock_session = no
pop3_uidl_format = %08Xu%08Xv
mail_plugins = quota
}
protocol lda {
postmaster_address = postmaster at tversu.ru
mail_plugins = quota cmusieve
sendmail_path = /usr/lib/sendmail
fsync_disable = no
}
auth_cache_size = 10240
auth_username_format = %Lu
auth default {
mechanisms = plain login cram-md5
socket listen {
master {
path = /var/run/dovecot/auth-master
mode = 0666
}
client {
path = /var/spool/postfix/private/auth
mode = 0666
user = postfix
group = postfix
}
}
passdb vpopmail {
args = cache_key=%u dovecot
}
userdb vpopmail {
}
user = vpopmail
ssl_require_client_cert = no
}
dict {
}
plugin {
quota = maildir:ignore=Trash
}
What can I do for resolving this locks?
May be, while looking into uidlist file, can dovecot LDA lock it? And
other deliver processes can't open it and wait for him?
---------------------------
WBR, Mike Grozak, TvSU IC
Hi all!
First of all, I want ti thank the whole Dovecot community (developers
for developing and fast responses, users for populating and responses
too). Dovecot is a really good and fast IMAP server - it serves near
3000 in our installation.
Now I have a problem and request community's help its resolving;)
Dovecot version: 1.0.13, compiled with vpopmail support.
I have an account spam at domain.com (:-), in which we put all our spam (we
gather statistic later). There can be 10 and more delivery attempts in a
second to maildir of this account during the spam attacks on our server.
The queue of our server can grow up to 20k messages, and all of these
messages are sent to spam at domain.com. I found a lot of such strings in
dovecot.log file during such DoS attack:
dovecot.log:deliver(spam at domain.com): May 16 04:18:48 Info:
msgid=<01c8b6da$a8bacf80$b7af2abe at sale>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:18:59 Info:
msgid=<6611811842.20080516012444 at poiusadfhnvxzmdiasdasgkhlsdkfg.com>:
save failed to INBOX: Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:06 Info:
msgid=<01c8b6a8$7b552e00$a0a4034c at sale>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:14 Info:
msgid=<360825920.32055246029506 at mirgames.ru>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:20:50 Info:
msgid=<01c8b6b1$0df9cb00$cc36dfc9 at tek2>: save failed to INBOX: Timeout
while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:21:00 Info:
msgid=<087901c7ca2d$ef272640$1e01a8c0 at telefonia.InterCable.net>: save
failed to INBOX: Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:21:01 Info:
msgid=<000701c8b6d2$01ff999f$c491aca7 at snoueiij>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:32 Info:
msgid=<000801c8b69b$060c0230$3cd8a4b7 at cpbvlrx>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:45 Info:
msgid=<000801c8b6a5$04ba6412$9910848d at aldldr>: save failed to INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:22:45 Info:
msgid=<031401c772e2$adc5be40$1e01a8c0 at mtu-net.ru>: save failed to
INBOX:
Timeout while waiting for lock
dovecot.log:deliver(spam at domain.com): May 16 04:23:08 Info:
msgid=<01c8b6db$0222fe80$b7af2abe at info>: save failed to INBOX: Timeout
while waiting for lock
What can I do for resolving this locks? The queue of my server becomes
really big!
May be, while looking into uidlist file, can dovecot LDA lock it? And
other deliver processes can't open it and wait for him?
$ dovecot --version
1.0.13
# dovecot -n
# 1.0.13: /etc/dovecot.conf
log_path: /var/log/dovecot.log
protocols: imap pop3
ssl_disable: yes
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
login_greeting: Server is ready.
login_process_per_connection: no
login_greeting_capability(default): yes
login_greeting_capability(imap): yes
login_greeting_capability(pop3): no
login_max_connections: 1024
first_valid_uid: 39
last_valid_uid: 39
first_valid_gid: 39
last_valid_gid: 39
fsync_disable: yes
maildir_copy_with_hardlinks: yes
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugins(default): quota imap_quota
mail_plugins(imap): quota imap_quota
mail_plugins(pop3): quota
mail_plugin_dir(default): /usr/lib/dovecot/imap
mail_plugin_dir(imap): /usr/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/pop3
auth default:
mechanisms: plain login cram-md5
default_realm: tversu.ru
cache_size: 10240
user: vpopmail
username_format: %Lu
passdb:
driver: vpopmail
args: cache_key=%u dovecot
userdb:
driver: vpopmail
socket:
type: listen
client:
path: /var/spool/postfix/private/auth
mode: 438
user: postfix
group: postfix
master:
path: /var/run/dovecot/auth-master
mode: 438
plugin:
quota: maildir:ignore=Trash
---------------------------
WBR, Mike Grozak, TvSU IC
Charles Marcus wrote:> On 5/22/2008, Mike Grozak (mike at tversu.ru) wrote: >> >> First of all, I want ti thank the whole Dovecot community (developers >> for developing and fast responses, users for populating and responses >> too). Dovecot is a really good and fast IMAP server - it serves near >> 3000 in our installation. > > What filesystem is this on?ext3. How can I escape dovecot-uidlist locking? it really locks my system! --------------------------- WBR, Mike Grozak, TvSU IC
On 5/22/2008, Mike Grozak (mike at tversu.ru) wrote:> > First of all, I want ti thank the whole Dovecot community (developers > for developing and fast responses, users for populating and responses > too). Dovecot is a really good and fast IMAP server - it serves near > 3000 in our installation.What filesystem is this on? -- Best regards, Charles