Travis, Here are a couple more graphs showing the requests/sec and network traffic for both varnish and nginx:
http://i1217.photobucket.com/albums/dd391/bstillwell_pb/Graphs/varnish-vs-nginx2.png As for testing method, that involved having both servers equally weighted on an F5 load balancer taking production traffic. The F5 was configured to re-use connections when possible with one-connect, and to use persistent hashing to always send the same requests to the same caching server. As for the configurations for both I'll send those to you in a private email. Bryan On Fri, Aug 16, 2013 at 12:10 PM, Crowder, Travis <[email protected]> wrote: > Can you publish your testing methods and configurations for both Varnish > and Nginx? Can you include the Network graphs and/or the Connections > graphs for Varnish and Nginx? > > -Travis > > On 8/16/13 12:29 PM, "Bryan Stillwell" <[email protected]> wrote: > >>I'm looking at converting all of our nginx caching servers over to >>varnish, but I'm seeing some oddities with the 'file' storage backend >>that I'm hoping someone could shed some light on. >> >>Hardware specs for both machines: >> >>Dell PowerEdge R610 >> Dual Xeon E5620 @ 2.40GHz >> 64GiB memory >> 4x 240GB SSDs in a RAID5 attached to a PERC H700 RAID controller >> >>The following image compares CPU, memory, and IOPS for both a machine >>running varnish (left), and one running nginx (right): >> >>http://i1217.photobucket.com/albums/dd391/bstillwell_pb/Graphs/varnish-vs- >>nginx.png >> >>At the most recent sample, each machine was handling ~350 requests/sec. >> >>As you can see the varnish machine has a lot more CPU time dedicated to >>I/O wait, which matches up with ~5x higher IOPS numbers. However, the >>biggest difference is that varnish is using ~25x more read IOPS than >>nginx. >> >>As for the jumps in the IOPS graph, I believe they can be explained by: >> >>Wednesday @ 10:00a: Started taking traffic >>Wednesday @ 11:00a: Memory cache filled, started using SSDs >>Wednesday @ 4:00p: TTL of 6 hours was hit, objects start expiring >>Wednesday @ 7:15p: SSD cache filled >> >>I pre-allocated the storage with fallocate (fallocate -l 450g >>/cache/varnish_storage.bin) to make sure that wasn't helping contribute >>to the issue. >> >>Any ideas on what could be tuned to reduce the number of read IOPS to be >>more inline with nginx? >> >>Thanks, >>Bryan >> >>_______________________________________________ >>varnish-misc mailing list >>[email protected] >>https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc >> > -- Bryan Stillwell SENIOR SYSTEM ADMINISTRATOR E: [email protected] O: 303.228.5109 M: 970.310.6085 _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
