Re: 128 Bucket Failures?
On Nov 13, 2008, at 1:34 PM, Ivan Voras wrote: Chris Pratt wrote: I have asked this before a couple of years ago but received no replies. I assumed that's because it's a somewhat obscure question. I'm still interested and thought I might try again in case someone new is watching this list who might know. A vmstat -z on my highest traffic server always shows the failures as below on 128 Bucket. It also goes to having 0 free rather soon after the system is restarted and never returns to having more than 1 free in that column and yet always has the highest number of requests by far. Does this mean anything significant? Is it something I should tune or even can be tuned? UMA buckets seem to be some kind of cache for SMP-optimized allocations - I hope someone who knows it better will explain them. Here is the output of the vmstat -z with everything chopped out besides the 128 Bucket line. The machine it's on is an 8 core 8 GB Tyan and shouldn't really be starved for anything in my way of thinking. vmstat -z ITEM SIZE LIMIT USED FREE REQUESTS FAILURES 128 Bucket: 1048,0, 2043,0, 13591, 6511069 What is the server used for? A busy webserver (about 5G Views a month, average view is 3-4 hits). Not really large pages, we keep graphics minimal. It's apache, perl cgi, mysqld. Tends to collect a lot of garbage traffic attacks on top of real traffic, both TCP and UDP. Here's a snapshot from a very loaded apache+php+pgsql web server, uptime 60 days (since the last power outage): 16 Bucket: 76,0, 42, 58, 125, 0 32 Bucket:140,0, 76, 64, 183, 0 64 Bucket:268,0, 74, 38, 438, 11 128 Bucket: 524,0, 2060, 642, 788828, 6985 A generic advice would be to increase vm.kmem_size (you're using AMD64, right?) and see what happens. I'll try that. I had heard this before in relation to KVA but have been concerned about trying it. If I can just change that knob and have an effect, seems worth a try. If more than one person is doing it, it must be safe? Yes, AMD64. Thank you very much. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: 128 Bucket Failures?
Chris Pratt wrote: > I have asked this before a couple of years ago but received no > replies. I assumed that's because it's a somewhat obscure question. > I'm still interested and thought I might try again in case someone > new is watching this list who might know. > > A vmstat -z on my highest traffic server always shows the failures > as below on 128 Bucket. It also goes to having 0 free rather soon > after the system is restarted and never returns to having more than > 1 free in that column and yet always has the highest number of > requests by far. Does this mean anything significant? Is it > something I should tune or even can be tuned? UMA buckets seem to be some kind of cache for SMP-optimized allocations - I hope someone who knows it better will explain them. > Here is the output of the vmstat -z with everything chopped out > besides the 128 Bucket line. The machine it's on is an 8 core 8 GB > Tyan and shouldn't really be starved for anything in my way of thinking. > > vmstat -z > ITEM SIZE LIMIT USED FREE REQUESTS > FAILURES > > 128 Bucket: 1048,0, 2043,0,13591, > 6511069 What is the server used for? Here's a snapshot from a very loaded apache+php+pgsql web server, uptime 60 days (since the last power outage): 16 Bucket: 76,0, 42, 58, 125, 0 32 Bucket:140,0, 76, 64, 183, 0 64 Bucket:268,0, 74, 38, 438, 11 128 Bucket: 524,0, 2060, 642, 788828, 6985 A generic advice would be to increase vm.kmem_size (you're using AMD64, right?) and see what happens. signature.asc Description: OpenPGP digital signature
128 Bucket Failures?
I have asked this before a couple of years ago but received no replies. I assumed that's because it's a somewhat obscure question. I'm still interested and thought I might try again in case someone new is watching this list who might know. A vmstat -z on my highest traffic server always shows the failures as below on 128 Bucket. It also goes to having 0 free rather soon after the system is restarted and never returns to having more than 1 free in that column and yet always has the highest number of requests by far. Does this mean anything significant? Is it something I should tune or even can be tuned? Here is the output of the vmstat -z with everything chopped out besides the 128 Bucket line. The machine it's on is an 8 core 8 GB Tyan and shouldn't really be starved for anything in my way of thinking. vmstat -z ITEM SIZE LIMIT USED FREE REQUESTS FAILURES 128 Bucket: 1048,0, 2043,0, 13591, 6511069 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"