How's your server load?
boutilpj at ednet.ns.ca
Thu Dec 20 08:26:49 EST 2012
On 12/20/2012 07:36 AM, Paolo Cravero wrote:
> anyone is willing to comment on this Cyrus server load, or share theirs?
> Virtual machine on vSphere 5 with 2x 2 GHz vCPU;
> cyrus-imapd RPM 2.4.16;
> kernel 2.6.18 x64_64;
> 4 GB RAM.
> There are 150 simultaneous IMAP connections on average mostly coming
> from a webmail (openXchange), with 240 imapd processes. No POP3. Just
> one instance of cyrus. Messages come over LMTP at a rate of 1
> msg/second, average of course.
> Data and metadata partitions are local to the virtual machine (not NFS),
> connected to a SAN via FC.
> The system has 20 data partitions (and 20 metadata), for a total of
> 3.8TB, of which 550GB are used. Mailboxes (accounts) sum up to 2000.
> What is bugging me is the system load that averages at 10 during peak
> hours. CPU usage is equally shared between user/system/idle. As reported
> by vmstat:
> us sy id wa st
> 33 31 32 4 0
> These figures obviously vary each second, but don't go too far during
> peak hours.
> /proc/meminfo reports:
> MemTotal: 4043792 kB
> MemFree: 34416 kB
> Buffers: 305456 kB
> Cached: 2505672 kB
> SwapCached: 0 kB
> Active: 2393176 kB
> Inactive: 1083692 kB
> HighTotal: 0 kB
> HighFree: 0 kB
> LowTotal: 4043792 kB
> LowFree: 34416 kB
> SwapTotal: 4192956 kB
> SwapFree: 4192724 kB
> Dirty: 86608 kB
> Writeback: 0 kB
> AnonPages: 665816 kB
> Mapped: 95900 kB
> Slab: 445736 kB
> PageTables: 55056 kB
> NFS_Unstable: 0 kB
> Bounce: 0 kB
> CommitLimit: 6214852 kB
> Committed_AS: 1018640 kB
> VmallocTotal: 34359738367 kB
> VmallocUsed: 265672 kB
> VmallocChunk: 34359472247 kB
> HugePages_Total: 0
> HugePages_Free: 0
> HugePages_Rsvd: 0
> Hugepagesize: 2048 kB
> The userbase is going to grow. Another group of 3500 users with 2TB/year
> traffic is going to go on a dedicated cyrus server, similar to the one
> detailed above.
> Not having a direct experience on large and active userbase under Cyrus,
> the load seems high compared to other solutions we know of. I would
> appreciate any input about the apparent ability of the current server to
> hold more users, or which debugging/characterization steps should be
> undertaken to further optimize our asset.
> The "Performance Notes" page has been studied and applied when possible.
> Thank you for reading so far and Season's Greetings, if applies.
> Cyrus Home Page: http://www.cyrusimap.org/
> List Archives/Info: http://lists.andrew.cmu.edu/pipermail/info-cyrus/
> To Unsubscribe:
64G of RAM
2 x X5670 Intel (6 core) processors
H700 PERC RAID card. RAID1 config for each mount point. /var/imap on SAS
15K disks while mail spool on 2TB nearline SAS (SATA) drives.
Cyrus IMAP 2.4.17 from source
Linux kernel is 2.6.18-308.16.1.el5
We have 10000 active users with about 500 concurrent connections.
Our load average is around 3 normally but goes as high as 20 once in a
while. But even when at 20 the system is not noticeably slow.
I suggest more RAM so more of the filesystem will be cached. And a fast
disk subsystem helps as well.
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