Re: Does softupdate help squid ?
On Mon, 17 Mar 2008 12:26:11 -0400
Christopher Sean Hilton [EMAIL PROTECTED] wrote:
Thanks for the enlightenment. My understanding is that Squid can do
both forward and reverse proxy. At least it it would seem so since
that's the way I'm using it. I did not know that varnish cannot be
used as a forward proxy though. As I said before, varnish is on my
list of things to investigate since it seems to have a much more
modern design than squid.
Varnish does look very interesting (specially the configuration side of
things). But, as you point out, it seems a more specific than Squid (or squid
more flexible, whatever :) ).
btw, does Squid 3 finally implement ESI?
B
_
{Beto|Norberto|Numard} Meijome
Everything should be made as simple as possible, but not simpler.
Albert Einstein
I speak for myself, not my employer. Contents may be hot. Slippery when wet.
Reading disclaimers makes you go blind. Writing them is worse. You have been
Warned.
___
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
On Mon, 17 Mar 2008 09:51:58 +0100 Frank Bonnet [EMAIL PROTECTED] wrote: Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? Yes, use soft-updates. And you should mount any dedicated cache partitions as noatime. It's also a good idea to build in aufs support and use that in your cache_dir entry, instead of the standard ufs cache type which blocks on disk i/o. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
On Mar 17, 2008, at 4:51 AM, Frank Bonnet wrote: Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? I can't imagine that it would hurt. Last I looked though squid may not be the best tool for this job. Poul Henning-Kamp has written an http accelerator called varnish. I'll start by saying that implementing varnish is on list of things to do so my experience is purely anecdotal. No that I've said that, the feature that grabbed my attention was the fact that it's written to modern unix. If I understand what I read correctly this means that varnish eschews squids separation of the cache into a fast cache in memory and a slow cache on disk. Instead varnish uses a big memory mapped file allowing the operating system to manage which cache objects are in memory and which ones are on disk. On FreeBSD at least that would seem to me to be a bigger performance win than softupdates. -- Chris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: Does softupdate help squid ?
Squid is a forward proxy whereas varnish is just a reverse proxy So you can not use it for for lan to wan proxy! Regards, Johan -Oorspronkelijk bericht- Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Christopher Sean Hilton Verzonden: maandag 17 maart 2008 12:41 Aan: Frank Bonnet Onderwerp: Re: Does softupdate help squid ? On Mar 17, 2008, at 4:51 AM, Frank Bonnet wrote: Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? I can't imagine that it would hurt. Last I looked though squid may not be the best tool for this job. Poul Henning-Kamp has written an http accelerator called varnish. I'll start by saying that implementing varnish is on list of things to do so my experience is purely anecdotal. No that I've said that, the feature that grabbed my attention was the fact that it's written to modern unix. If I understand what I read correctly this means that varnish eschews squids separation of the cache into a fast cache in memory and a slow cache on disk. Instead varnish uses a big memory mapped file allowing the operating system to manage which cache objects are in memory and which ones are on disk. On FreeBSD at least that would seem to me to be a bigger performance win than softupdates. -- Chris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
On Mar 17, 2008, at 11:51 AM, Johan Hendriks wrote: Squid is a forward proxy whereas varnish is just a reverse proxy So you can not use it for for lan to wan proxy! Thanks for the enlightenment. My understanding is that Squid can do both forward and reverse proxy. At least it it would seem so since that's the way I'm using it. I did not know that varnish cannot be used as a forward proxy though. As I said before, varnish is on my list of things to investigate since it seems to have a much more modern design than squid. -- Chris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? i would say it's absolutely needed. anyway - any reason to not use soft updates on every filesystem? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
On Monday 17 March 2008 19:17:58 Wojciech Puchar wrote: Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? i would say it's absolutely needed. anyway - any reason to not use soft updates on every filesystem? What exactly is a soft update? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Does softupdate help squid ?
On Mon, Mar 17, 2008 at 07:34:04PM +, Pollywog wrote: On Monday 17 March 2008 19:17:58 Wojciech Puchar wrote: Hello I'm setting up a squid cache (3.0.2) machine FreeBSD 7.0 based and I wonder if softupdates could help (make it faster ) or not the cache partition ? i would say it's absolutely needed. anyway - any reason to not use soft updates on every filesystem? What exactly is a soft update? It's a bit like a hard update, but it won't hurt your disks as much if your system crashes... ;-P On a more serious note, it's a technique for ensuring the integrity of disks after a system crash or power failure. Like journalling, they don't guarantee data won't be lost, but instead that the disks will be in a consistent state at recovery. There are many many papers on the subject on the web, if you're interested. Dan -- Daniel Bye _ ASCII ribbon campaign ( ) - against HTML, vCards and X - proprietary attachments in e-mail / \ pgpUrSxD2B4H7.pgp Description: PGP signature
Re: Does softupdate help squid ?
On Mar 17, 2008, at 4:14 PM, Daniel Bye wrote: On Mon, Mar 17, 2008 at 07:34:04PM +, Pollywog wrote: On Monday 17 March 2008 19:17:58 Wojciech Puchar wrote: i would say it's absolutely needed. anyway - any reason to not use soft updates on every filesystem? What exactly is a soft update? It's a bit like a hard update, but it won't hurt your disks as much if your system crashes... ;-P On a more serious note, it's a technique for ensuring the integrity of disks after a system crash or power failure. Like journalling, they don't guarantee data won't be lost, but instead that the disks will be in a consistent state at recovery. Soft updates is a means of re-ordering the writes to a filesystem such that the complete filesystem, both data and meta data, remains reasonably consistent during the writing process. This consistency is necessary insurance in case of a system crash or power failure during the writing process. Soft updates seeks to re-order the writes in such a way that the filesystem can be safely recovered by an automatic fsck process when the system is restarted. At the same time soft updates works to maintain high system performance . Previous to soft updates you could either mount the filesystem synchronously or asynchronously. With Synchronous mounts the filesystem meta data writes were handled before data writes. This caused excessive and expensive seeking from the disk mechanism as it moved from one part of the disk to update the meta-data to the other part of the disk to write the application data. With an asynchronous mount the kernel was free to perform the writes in the order most beneficial for performance but if the system crashed in the middle of a write one could expect a very difficult situation for fsck to fix. My squid is on OpenBSD. My cache partition is spread across two spindles of a drive provided by the ccd driver mounted either asynchronously or with soft updates. Either way is fine because if my squid machine were to crash so hard that the cache partition was toast it wouldn't take but 10 minutes rebuild the filesystem from scratch and use squid -z to reinitialize it. For me there's really no data on there worthy of softupdates. -- Chris ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
