Multiple varnish instances per server?
Hi, Is anyone running multiple varnish instances per server (one per disk or similar?) We are currently running a single varnish instance per server using the file backend. Machines are Dual Opteron 2218, 4GB RAM, and 2 250GB SATA drives. We have the cache file on a software RAID 0 array. Our cache size is set to 300GB, but once we get to 100GB or so, IO starts to get very spiky, causing loads to spike into the 100 range. Our expires are rather long (1-2 weeks). My initial thoughts were that this was caused by cache file fragmentation, but we are seeing similar issues when using the malloc backend. We were thinking that running 2 instances per server with smaller cache files (one per physical disk), may improve our IO problems. Is there any performance benefit/detriment to running multiple varnish instances per server? Is there a performance hit for having a large cache? Request rates aren't that high (50-150/sec), but the cached files are all images, some of which can be rather big (3MB). Also, is anyone else seeing similar issues under similar workloads? -- Barry Abrahamson | Systems Wrangler | Automattic Blog: http://barry.wordpress.com ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc
Re: Multiple varnish instances per server?
In message [EMAIL PROTECTED], Barry Abrahams on writes: Hi, Is anyone running multiple varnish instances per server (one per disk or similar?) Just remember to set the -n argument to something different. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc
Re: Multiple varnish instances per server?
Why are you using Varnish to serve primarily images? Modern webservers serve static files very efficiently off the filesystem. Best regards, --Michael On Sun, Jun 1, 2008 at 8:58 AM, Barry Abrahamson [EMAIL PROTECTED] wrote: Hi, Is anyone running multiple varnish instances per server (one per disk or similar?) We are currently running a single varnish instance per server using the file backend. Machines are Dual Opteron 2218, 4GB RAM, and 2 250GB SATA drives. We have the cache file on a software RAID 0 array. Our cache size is set to 300GB, but once we get to 100GB or so, IO starts to get very spiky, causing loads to spike into the 100 range. Our expires are rather long (1-2 weeks). My initial thoughts were that this was caused by cache file fragmentation, but we are seeing similar issues when using the malloc backend. We were thinking that running 2 instances per server with smaller cache files (one per physical disk), may improve our IO problems. Is there any performance benefit/detriment to running multiple varnish instances per server? Is there a performance hit for having a large cache? Request rates aren't that high (50-150/sec), but the cached files are all images, some of which can be rather big (3MB). Also, is anyone else seeing similar issues under similar workloads? -- Barry Abrahamson | Systems Wrangler | Automattic Blog: http://barry.wordpress.com ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc
Re: Multiple varnish instances per server?
\On Jun 1, 2008, at 1:38 PM, Michael S. Fischer wrote: Why are you using Varnish to serve primarily images? Modern webservers serve static files very efficiently off the filesystem. Because we have about 6TB of content and are using Varnish as the hot cache and S3 as the cold store. -- Barry Abrahamson | Systems Wrangler | Automattic Blog: http://barry.wordpress.com ___ varnish-misc mailing list varnish-misc@projects.linpro.no http://projects.linpro.no/mailman/listinfo/varnish-misc
