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bio website craters-of-the-mind.blogspot.…
location Moscow, Russia
age 32
visits member for 5 years, 2 months
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mailto: ag@logiceditor.com


Nov
7
revised Uneven CPU core utilization
grr
Nov
7
answered Uneven CPU core utilization
Nov
7
comment Uneven CPU core utilization
@DavidSchwartz: How to check that?
Nov
6
comment Uneven CPU core utilization
@FINESEC: I'll check static pages and will update ticket. As for business logic — I believe that there should be tools to figure out what is going on without delving into the code. It is rather complex anyway. (That being said, it is single-threaded and no explicit synchronization stuff is used.)
Nov
6
comment Uneven CPU core utilization
It is 1am here, sorry. Maybe tomorrow. Meanwhile I've updated the question with htop screenshot.
Nov
6
revised Uneven CPU core utilization
minor wording tuning
Nov
6
accepted Filesystem speed shaper for Linux
Nov
6
comment Uneven CPU core utilization
Testing is done by running ab -n 100000 -q -c 20 http://my.example.com, from six different external machines.
Nov
6
revised Uneven CPU core utilization
clarified
Nov
6
comment Uneven CPU core utilization
Worker processes are Lua-based, and do some non-trivial business logic (including communication over network with other machines), so 800 rps is more or less OK (but there is some room for optimization). That being said, please note that this question is specifically about uneven CPU core utilization.
Nov
6
comment Uneven CPU core utilization
Well, all cores except the first one are consistently under-loaded, and first core is consistently over-loaded. Looks fishy to me.
Nov
6
revised Uneven CPU core utilization
clarified subject
Nov
6
asked Uneven CPU core utilization
Nov
3
awarded  Nice Question
Oct
30
comment Troubleshooting poor disk IO performance
deadline on Xen, noop on VM seems to be the best option. We still have to analyze data properly, but while other combination trigger 500-1100 502 errors (with stable traffic load), while deadline-noop triggers 0-600 502s (with the same load). However it still stalls. Is there anything else we can tune?
Oct
30
comment Troubleshooting poor disk IO performance
No battery-backed or flash-backed cache, sadly. This is a plain and humble Hetzner box.
Oct
30
comment Troubleshooting poor disk IO performance
It seems that I'm using deadline scheduler. Will try noop and (for completeness) cfq.
Oct
30
comment Troubleshooting poor disk IO performance
See dstat and iostat dumps here: groups.google.com/forum/#!msg/redis-db/vSAvnYVtX9w/NRYlBwOrCTsJ
Oct
30
comment Troubleshooting poor disk IO performance
It says noop [deadline] cfq on VM.
Oct
30
comment Craft a file that ignores all writes without being marked as read-only
Interesting idea, thank you. Looks like a way to go, unless there is a ready-made solution of some kind.