>> So we use about ten common Intel based servers for BEs (sized to >> support loss of 2/3 servers) and store data on NAS. Users are active >> and filer is about tens of thousand nfsop/s at the busy hour. >> >> About 10% to 20% of the users connect at least one time a day, globally >> 4 million connections per day. > These are quite massive figures -- I'm thoroughly impressed. I am > assuming that your back-ends experience 50,000-100,000 concurrent IMAP > connections during certain parts of the day. This means that each BE > takes 5,000-10,000 parallel connections. Can an ordinary Intel server > handle such loads? What's the CPU and RAM of each? We don't have to handle such load. Most of end-users connect on pop3d (we provide a pop3 optimizer to reduce I/O, see http://www.mail-archive.com/cyrus-devel@xxxxxxxxxxxxxxxxxxxx/msg01194.html) , others connect on the webmail (our webmail uses disconnected imapd sessions and is optimized thanks to Cyrus statuscache db). > Also, how many NAS servers/appliances are being used? I would have > thought that something like NFS would be too slow for such heavy IO > loads, but evidently I'm wrong. One huge is enough and cheaper than a SAN. Also we have very experienced system admins to tune the filer ! Ce message et les pièces jointes sont confidentiels et réservés à l'usage exclusif de ses destinataires. Il peut également être protégé par le secret professionnel. Si vous recevez ce message par erreur, merci d'en avertir immédiatement l'expéditeur et de le détruire. L'intégrité du message ne pouvant être assurée sur Internet, la responsabilité du groupe Atos Origin ne pourra être recherchée quant au contenu de ce message. Bien que les meilleurs efforts soient faits pour maintenir cette transmission exempte de tout virus, l'expéditeur ne donne aucune garantie à cet égard et sa responsabilité ne saurait être recherchée pour tout dommage résultant d'un virus transmis. This e-mail and the documents attached are confidential and intended solely for the addressee; it may also be privileged. If you receive this e-mail in error, please notify the sender immediately and destroy it. As its integrity cannot be secured on the Internet, the Atos Origin group liability cannot be triggered for the message content. Although the sender endeavours to maintain a computer virus-free network, the sender does not warrant that this transmission is virus-free and will not be liable for any damages resulting from any virus transmitted. ---- Cyrus Home Page: http://www.cyrusimap.org/ List Archives/Info: http://lists.andrew.cmu.edu/pipermail/info-cyrus/
