>From what I understand sm_bfree is the amount of bytes that are free in the >cache while sm_balloc is the amount of used bytes in the cache (at least with >varnish version 2.1.5). What I'm trying to understand is why two servers with >the exact same hardware and varnish configuration that are using the same >backends can have such a drastic difference with regards to these stats. Both >server have 48GB of RAM. On both servers I have configured a cache size of 48 >GB like so:
-s file,/tmp/varnish-cache,48G If I add up sm_bfree and sm_balloc on both servers they equal 48GB: varnish1: [root@varnish1 ~]# varnishstat -1 | egrep 'sm_bfree|sm_balloc' sm_balloc 13053640704 . bytes allocated sm_bfree 38485966848 . bytes free [root@varnish1 ~]# echo 'scale=3;(13053640704 + 38485966848) / 1024 / 1024 / 1024' | bc 48.000 varnish2: [root@varnish2 ~]# varnishstat -1 | egrep 'sm_bfree|sm_balloc' sm_balloc 48657035264 . bytes allocated sm_bfree 2882572288 . bytes free [root@varnish2 ~]# echo 'scale=3;(48657035264 + 2882572288) / 1024 / 1024 / 1024' | bc 48.000 Can anyone explain to me why varnish2 uses so much more cache than varnish1? varnish1 has been running for 24 days and it maintains the ratio of bytes allocated to bytes free by frequently lru nuking. (This average to ~ 60 lru nukes per second in MRTG) This server has been quite stable; however I have noticed a lot of disk I/O. The problem with varnish2 is that it does no lru nuking until the cache is nearly full, at which point the worker thread count maxes out (6000 in my case) and no new clients can connect. Because of this I am only able to run this server for ~ 48 hours before I have to restart varnish. Thanks, Matt Schurenko Systems Administrator airG(r) Share Your World Suite 710, 1133 Melville Street Vancouver, BC V6E 4E5 P: +1.604.408.2228 F: +1.866.874.8136 E: [email protected] W: www.airg.com<http://www.airg.com> airG is one of BC's Top 55 Employers and Canada's Top Employers for Young People P Please consider the environment before printing this e-mail. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material communicated under NDA. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.
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