抱歉，帖子太长了，大部分都是配置细节。
我最近从单线程 cyrus 服务器（其中多个域作为多个虚拟域在一个侦听器上过载）更改为多线程 cyrus 服务器（其中多个域在具有单独配置的不同 ip 地址上侦听）。主要动机是为每个域设置单独的 tls 证书。问题是，我可以在所有 ip/端口上连接到所有域的 cyrus 侦听器，但其中一个会立即分叉并用横幅响应，而其他会延迟几秒钟到一分钟左右的时间，然后分叉并用横幅响应。使用相同的设置，我更改为单线程 cyrus 服务器以侦听所有 ip/端口，然后我会立即得到所有响应，但我当然不会获得单独的 tls 证书或配置。在单线程和多线程配置之间切换会触发问题，这是可以复制的。我搜索了日志和邮件列表，但没有发现任何相关的内容。
问题：为什么连接到主侦听器后，切换到多线程 Cyrus 服务器会触发 imapd 进程的延迟分叉？
在立即响应的听众（正如预期的那样）上我得到了这个：
user@somehost:~> telnet imap.domain1.com 143
Trying 192.168.110.171...
Connected to imap.domain1.com.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ ID ENABLE STARTTLS AUTH=GSS-SPNEGO AUTH=GSSAPI AUTH=DIGEST-MD5 AUTH=CRAM-MD5 AUTH=LOGIN AUTH=PLAIN SASL-IR] imap.domain1.com Cyrus IMAP v2.4.18 server ready
在延迟的监听器上，我得到了这个（并且进程挂起几秒钟甚至一两分钟）：
user@somehost:~> telnet imap.domain2.com 143
Trying 192.168.110.172...
Connected to imap.domain2.com.
Escape character is '^]'.
据我所知，监听器响应的域和延迟的域似乎会发生变化并且是随机的。
当我们连接并获得 for 时以及当我们连接并获得延迟时，日志日志中没有任何内容看起来不同。
May 19 09:44:31 MAILSERVER master[13762]: about to exec /usr/lib/cyrus/bin/imapd
May 19 09:44:31 MAILSERVER imap[13762]: executed
May 19 09:44:31 MAILSERVER imap[13762]: IOERROR: opening /var/lib/imap/user_deny.db: No such file or directory
一旦 imapd forks 和 banner 生成
5月19日 09:46:45 邮件服务器 imap[13762]: 已接受连接
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/lib/imap/socket
SERVICES {
# add or remove based on preferences
#imap cmd="imapd" listen="imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain1.com.conf " listen="192.168.171.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain1.com.conf " listen="192.168.110.171:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain2.com.conf " listen="192.168.172.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain2.com.conf " listen="192.168.110.172:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain3.com.conf " listen="192.168.174.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain3.com.conf " listen="192.168.110.174:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain4.com.conf " listen="192.168.175.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain4.com.conf " listen="192.168.110.175:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain5.com.conf " listen="192.168.176.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain5.com.conf " listen="192.168.110.176:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain6.com.conf " listen="192.168.177.4:imap" maxchild=-1 maxforkrate=100
imap cmd="imapd -C /etc/imapd.domain6.com.conf " listen="192.168.110.177:imap" maxchild=-1 maxforkrate=100
#imaps cmd="imapd -s" listen="imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain1.com.conf -s " listen="192.168.171.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain1.com.conf -s " listen="192.168.110.171:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain2.com.conf -s " listen="192.168.172.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain2.com.conf -s " listen="192.168.110.172:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain3.com.conf -s " listen="192.168.174.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain3.com.conf -s " listen="192.168.110.174:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain4.com.conf -s " listen="192.168.175.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain4.com.conf -s " listen="192.168.110.175:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain5.com.conf -s " listen="192.168.176.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain5.com.conf -s " listen="192.168.110.176:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain6.com.conf -s " listen="192.168.177.4:imaps" maxchild=-1 maxforkrate=100
imaps cmd="imapd -C /etc/imapd.domain6.com.conf -s " listen="192.168.110.177:imaps" maxchild=-1 maxforkrate=100
#pop3 cmd="pop3d" listen="pop3"
#pop3s cmd="pop3d -s" listen="pop3s"
#sieve cmd="timsieved" listen="sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain1.com.conf" listen="192.168.171.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain1.com.conf" listen="192.168.110.171:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain2.com.conf" listen="192.168.172.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain2.com.conf" listen="192.168.110.172:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain3.com.conf" listen="192.168.174.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain3.com.conf" listen="192.168.110.174:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain4.com.conf" listen="192.168.175.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain4.com.conf" listen="192.168.110.175:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain5.com.conf" listen="192.168.176.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain5.com.conf" listen="192.168.110.176:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain6.com.conf" listen="192.168.177.4:sieve" maxchild=-1 maxforkrate=100
sieve cmd="timsieved -C /etc/imapd.domain6.com.conf" listen="192.168.110.177:sieve" maxchild=-1 maxforkrate=100
#ptloader cmd="ptloader" listen="/var/lib/imap/ptclient/ptsock"
# at least one LMTP is required for delivery
lmtp cmd="lmtpd -a" listen="mail.domain1.com:lmtp" maxchild=-1 maxforkrate=100
lmtp cmd="lmtpd -a" listen="mail.domain2.com:lmtp" maxchild=-1 maxforkrate=100
lmtp cmd="lmtpd -a" listen="mail.domain3.com:lmtp" maxchild=-1 maxforkrate=100
lmtp cmd="lmtpd -a" listen="mail.domain4.com:lmtp" maxchild=-1 maxforkrate=100
lmtp cmd="lmtpd -a" listen="mail.domain5.com:lmtp" maxchild=-1 maxforkrate=100
lmtp cmd="lmtpd -a" listen="mail.domain6.com:lmtp" maxchild=-1 maxforkrate=100
#lmtpunix cmd="lmtpd" listen="/var/lib/imap/socket/lmtp"
# this is only necessary if using notifications
#notify cmd="notifyd" listen="/var/lib/imap/socket/notify" proto="udp"
}
EVENTS {
# this is required
checkpoint cmd="ctl_cyrusdb -c" period=30
# this is only necessary if using duplicate delivery suppression,
# Sieve or NNTP
duplicateprune cmd="cyr_expire -E 3" at=0400
# Expire data older then 69 days. Two full months of 31 days
# each includes two full backup cycles, plus 1 week margin
# because we run our full backups on the first sat/sun night
# of each month.
deleteprune cmd="cyr_expire -E 4 -D 69" at=0430
expungeprune cmd="cyr_expire -E 4 -X 69" at=0445
# this is only necessary if caching TLS sessions
tlsprune cmd="tls_prune" at=0400
# Uncomment the next entry, if you want to automatically remove
# old messages of EVERY user.
# This example calls ipurge every 60 minutes and ipurge will delete
# ALL messages older then 120 days.
# enter 'man 8 ipurge' for more details
#cleanup cmd="ipurge -d 120 -f" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain1.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain2.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain3.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain4.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain5.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Spam*@domain6.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain1.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain2.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain3.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain4.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain5.com" period=60
cleanup cmd="ipurge -f -d 30 user/%/Trash*@domain6.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain1.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain2.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain3.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain4.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain5.com" period=60
cleanup cmd="ipurge -f -d 60 user/%/Sent*@domain6.com" period=60
# Create search indexes regularly
squatter cmd="squatter -s -i" at=0530
# running sa-learn
sa-learn cmd="/usr/local/bin/cyrus-salearn.pl" period=60
sa-update cmd="/usr/bin/sa-update -v" at=0000
}
/etc/imapd.domain1.com.conf
configdirectory: /var/lib/imap
partition-default: /var/spool/imap
sievedir: /var/lib/sieve
annotation_definitions: /etc/imapd.annotations.conf
# admins: [email protected]
allowanonymouslogin: no
autocreatequota: 10000
reject8bit: no
quotawarn: 90
timeout: 30
poptimeout: 10
dracinterval: 0
drachost: localhost
sasl_pwcheck_method: saslauthd
lmtp_overquota_perm_failure: no
#lmtp_catchall_mailbox: admin
lmtp_downcase_rcpt: yes
lmtp_fuzzy_mailbox_match: yes
expunge_mode: delayed
deletedprefix: DELETED
delete_mode: delayed
allowplaintext: yes
unixhierarchysep: yes
allowplainwithouttls: no
altnamespace: no
virtdomains: userid
servername: imap.domain1.com
#
# if you want lTLS, you have to generate certificates and keys
#
tls_cert_file: /etc/letsencrypt/live/imap.domain1.com/cert.pem
tls_key_file: /etc/letsencrypt/live/imap.domain1.com/privkey.pem
tls_ca_fie: /etc/letsencrypt/live/imap.domain1.com/chain.pem
tls_ca_path: /etc/ssl/certs
tls_versions: tls1_0 tls1_1 tls1_2
lmtp_admins: lmtpuser
注意：在我发现在单线程和多线程 Cyrus 服务器之间切换会触发分叉问题之前，我认为问题可能与资源限制有关。这就是我将所有进程设置为 maxchild=-1 maxforkrate=100 的原因。我还在 /etc/systemd/system/cyrus.service 中设置了以下内容
/etc/systemd/system/cyrus.service
[deleted...]
LimitRTPRIO=50000
LimitNOFILE=50000
LimitNPROC=50000
这些资源设置都没有任何区别，并且只要 cyrus 是单线程的，问题就会消失 - 所以我不认为这是一个资源限制（至少我现在理解这一点）。
任何帮助将非常感激。
答案1
Edda 于[电子邮件保护]。
问题是服务部分中的所有进程都具有相同的名称，这导致它们需要写入相同的锁定文件 var/lib/imap/socket。使用唯一名称（仅限字母数字 [a-z0-9]）重命名服务部分中的进程可停止阻塞。
/etc/cyrus.com 变成以下内容：
SERVICES {
# add or remove based on preferences
imap1 cmd="imapd -C /etc/imapd.domain1.com.conf " listen="192.168.171.4:imap" maxchild=-1 maxforkrate=100
imap2 cmd="imapd -C /etc/imapd.domain1.com.conf " listen="192.168.110.171:imap" maxchild=-1 maxforkrate=100
etc...
谢谢，艾达