>>>>> "ismael" == ismael tanguy at univ-brest fr <ismael.tanguy at univ-brest.fr> writes:ismael> I'm currently benchmarking new hardware aimed to serve around ismael> 70k users For now, our IMAP server have 13k users. This doesn't help us help you. Is this a new rasperry Pi 4? Is it a Dual CPU AMD Rzyzen with 128gb of memory and fast NVMe disks? What is your system setup? ismael> To run imaptest, I've spwan some bench clients. Are these tests run from remote hosts? What kind of network are you using? ismael> Each bench client can run imaptest with 1000 clients. ismael> More than 1000 clients will load CPU of this bench client ismael> imaptest command (command are chosen from usage stat on our other IMAP servers): ismael> imaptest host=xxxxx port=xxx userfile=userfile mbox=/root/dovecot-crlf ismael> pass=sxxxx seed=123 clients=1000 select=194 uidfetch=94 noop=70 ismael> status=82 append=49 fetch=276 list=12 store=19 expunge=22 ismael> msubs=4 search=4 logout=1 delete=81 no_pipelining ismael> With one bench client, everything runs smoothly. ismael> # ps aux | grep dovecot | awk '{print $11,$12,$13,$14,$15,$16,$17,$18}' | sort | uniq -c ismael> ? ?? 1 anvil: [221 connections] (anvil) ismael> ?? 1 auth: [13 wait, 0 passdb, 0 userdb] (auth) ismael> ?? 1 dovecot/config ismael> ?? 1 dovecot/imap ismael> ? 84 dovecot/imap-login ismael> ?? 1 dovecot/log ismael> ? 20 dovecot/pop3-login ismael> ?? 1 grep dovecot ismael> ?? 1 stats: [1307 connections] (stats) ismael> When a second instance bench instance start imaptest, clients ismael> of first and second instance begin to stall : ismael> ?1400 stalled for 20 secs in command: 1 LOGIN "fakeuser644 at mailbench...." "password" So how is your dovecot authentication setup? Are you using a mysql backend? LDAP? Where is the server you're querying against? Are you running mysql on the same server you're running dovecot on? Are you running multiple dovecot servers with dovecot director in front of them to help spread the load and to offer resilience if/when a backend server fails? ismael> And : ismael> # ps aux | grep dovecot | awk '{print $11,$12,$13,$14,$15,$16,$17,$18}' | sort | uniq -c ismael> ?? 1 anvil: [221 connections] (anvil) ismael> ?? 1 auth: [1227 wait, 0 passdb, 0 userdb] (auth) ismael> ?? 1 dovecot/config ismael> ?? 1 dovecot/imap ismael> ? 37 dovecot/imap-login ismael> ?? 1 dovecot/log ismael> ? 20 dovecot/pop3-login ismael> ?? 1 grep dovecot ismael> ?? 1 stats: [680 connections] (stats) ismael> Every auth go in wait, number of connection decreases. ismael> Using mysql or a password file give same results. Where is mysql located? ismael> I have used different values for service_count with also no success. Post your configuration details. ismael> I think my use of imaptest could be false. It could be. Are you thinking that 2000 users will all be logging into the system at the same time? ismael> My understanding of service auth is limited for now because ismael> I'm quite new to Dovecot (I have previously worked with ismael> Cyrus). Can't really give you any hints until you tell us more about your setup. John
Jorge Bastos
2022-Feb-07 22:41 UTC
On mailbox full, retry for 4 days or similar instead of reject
Howdy, I don't know if this is dovecot specific and i guess it may not be at 100% so I ask for help. I want postfix not to discard the message imediatly when a mailbox is full, i mean when postfix tries to deliver it to dovecot lmtp. Is it possible to change the behavior to something like what postfix does when he tries to deliver a message to an external server and the server is unaccessible for 4 days (the default i guess), and if in that period discard it. Does this exists? At least i know gmail does something similar to this. I've tried to google a bit but didn't found info that could lead me to this configuration. Thanks in advanced, Jorge -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://dovecot.org/pipermail/dovecot/attachments/20220207/a194cb51/attachment.htm>
Hello, thank you for your advices and sorry to not have detailed infra> ismael> I'm currently benchmarking new hardware aimed to serve around > ismael> 70k users For now, our IMAP server have 13k users. > > This doesn't help us help you. Is this a new rasperry Pi 4? Is it a > Dual CPU AMD Rzyzen with 128gb of memory and fast NVMe disks? What is > your system setup?Sorry, I have two servers to bench : - first one (a model like our current IMAP servers) is 18To HDD, 256Go RAM, 8c/16th - second (new one aimed to serve many more customers) is 24 x 14 TO (HDD SAS), 192GB DDR4 2,6Ghz, 12c/24t - 2.4GHz/3.5GHz OS is FreeBSD 12.2> > ismael> To run imaptest, I've spwan some bench clients. > > Are these tests run from remote hosts? What kind of network are you > using?Yes, imaptest is running from kvm remote virtual machines in the same DC. They are some networks hops between them, but few.> > ismael> Each bench client can run imaptest with 1000 clients. > ismael> More than 1000 clients will load CPU of this bench client > > ismael> imaptest command (command are chosen from usage stat on our other IMAP servers): > > ismael> imaptest host=xxxxx port=xxx userfile=userfile mbox=/root/dovecot-crlf > ismael> pass=sxxxx seed=123 clients=1000 select=194 uidfetch=94 noop=70 > ismael> status=82 append=49 fetch=276 list=12 store=19 expunge=22 > ismael> msubs=4 search=4 logout=1 delete=81 no_pipelining > > ismael> With one bench client, everything runs smoothly. > > ismael> # ps aux | grep dovecot | awk '{print $11,$12,$13,$14,$15,$16,$17,$18}' | sort | uniq -c > ismael> ? ?? 1 anvil: [221 connections] (anvil) > ismael> ?? 1 auth: [13 wait, 0 passdb, 0 userdb] (auth) > ismael> ?? 1 dovecot/config > ismael> ?? 1 dovecot/imap > ismael> ? 84 dovecot/imap-login > ismael> ?? 1 dovecot/log > ismael> ? 20 dovecot/pop3-login > ismael> ?? 1 grep dovecot > ismael> ?? 1 stats: [1307 connections] (stats) > > ismael> When a second instance bench instance start imaptest, clients > ismael> of first and second instance begin to stall : > > ismael> ?1400 stalled for 20 secs in command: 1 LOGIN"fakeuser644 at mailbench...." "password" > > So how is your dovecot authentication setup? Are you using a mysql > backend? LDAP? Where is the server you're querying against? Are you > running mysql on the same server you're running dovecot on?In production, we use a remote galera cluster. On benchmarking, for now, I use static for passdb and a file for userdb.> > Are you running multiple dovecot servers with dovecot director in > front of them to help spread the load and to offer resilience if/when > a backend server fails?No. I'm directly benchmarking backend.> > ismael> And : > > ismael> # ps aux | grep dovecot | awk '{print $11,$12,$13,$14,$15,$16,$17,$18}' | sort | uniq -c > ismael> ?? 1 anvil: [221 connections] (anvil) > ismael> ?? 1 auth: [1227 wait, 0 passdb, 0 userdb] (auth) > ismael> ?? 1 dovecot/config > ismael> ?? 1 dovecot/imap > ismael> ? 37 dovecot/imap-login > ismael> ?? 1 dovecot/log > ismael> ? 20 dovecot/pop3-login > ismael> ?? 1 grep dovecot > ismael> ?? 1 stats: [680 connections] (stats) > > ismael> Every auth go in wait, number of connection decreases. > > ismael> Using mysql or a password file give same results. > > Where is mysql located?Remote one, but I'll go, for now, with a passwd-file to exclude potentials DB problems at the beginning of benchmarking.> > ismael> I have used different values for service_count with also no success. > > Post your configuration details.#doveconf -n auth_cache_negative_ttl = 0 auth_cache_size = 100 M auth_cache_ttl = 2 mins auth_failure_delay = 5 secs auth_master_user_separator = * auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@%+ auth_username_translation = %@ auth_verbose = yes auth_worker_max_count = 500 base_dir = /var/run/dovecot/ default_client_limit = 100000 disable_plaintext_auth = no imap_idle_notify_interval = 30 secs listen = xxxxxxxxxxxx login_greeting = xxxxxxxxxxxxxxxxxx login_trusted_networks = xxxxxxxxxxxxxxxxxxx mail_gid = xxxx mail_uid = xxxx mailbox_list_index = no namespace { ? inbox = yes ? location ? prefix = INBOX. ? separator = . ? type = private } namespace { ? hidden = yes ? inbox = no ? list = no ? location ? prefix ? separator = . ? type = private } passdb { ? args = password=#hidden_use-P_to_show# ? driver = static } plugin { ? acl = vfile ? quota = maildir:User quota } protocols = imap pop3 service anvil { ? client_limit = 97000 ? unix_listener anvil-auth-penalty { ??? mode = 00 ? } } service auth-worker { ? client_limit = 1 ? idle_kill = 0 ? process_limit = 6000000 ? process_min_avail = 0 ? service_count = 1 ? vsz_limit = 18446744073709551615 B } service auth { ? client_limit = 0 ? idle_kill = 0 ? process_limit = 1 ? process_min_avail = 1 ? service_count = 0 ? vsz_limit = 1000 M } service imap-login { ? client_limit = 26000 ? process_min_avail = 16 ? service_count = 0 ? vsz_limit = 1 G } service imap { ? drop_priv_before_exec = yes ? process_limit = 10000 } service pop3-login { ? service_count = 0 } service pop3 { ? drop_priv_before_exec = yes ? process_limit = 10000 } ssl = no userdb { driver = passwd-file ? args = username_format=%Ln /usr/local/etc/dovecot/passwd-file default_fields = uid=xxxx gid=xxxx } verbose_proctitle = yes version_ignore = yes protocol imap { ? imap_max_line_length = 64 k ? mail_max_userip_connections = 100000 ? mail_plugins = quota imap_quota acl } protocol pop3 { ? mail_max_userip_connections = 100 ? mail_plugins = quota ? pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s ? pop3_uidl_format = %f } ismael> I think my use of imaptest could be false. It could be. Are you thinking that 2000 users will all be logging into the system at the same time? No, except when a backend is restarted, so I put delay on imaptest command : imaptest host=xxx port=143 userfile=userfile mbox=/root/dovecot-crlf pass=password seed=123 ??? clients=1000 delay=5 secs=3600 select=194 uidfetch=94 noop=70 status=82 append=49 ??? fetch=276 list=12 store=19 expunge=22 msubs=4 search=4 logout=10 delete=81 no_pipelining> > ismael> My understanding of service auth is limited for now because > ismael> I'm quite new to Dovecot (I have previously worked with > ismael> Cyrus). > > Can't really give you any hints until you tell us more about your > setup.I understand, sorry again, hoping this new details are enough. Thanks, Isma?l -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://dovecot.org/pipermail/dovecot/attachments/20220208/60bf34fb/attachment.htm>