Re: Recommended value for max-cache-size for cache-only shared hosts..
At Mon, 04 Jun 2012 12:53:31 -0700, Doug Barton do...@dougbarton.us wrote: If your cache is too small the CPU will peg when the cleaning-interval goes. Maybe that's changed but the behavior still exists in the 9.7 branch. Setting your cache size really depends on your query load. On a resolver doing 15,000/qps having a cache of 256M will cause a problem during the cleaning-interval whereas if it's 2G you won't notice the interval at all. Also on a busy resolver expect BIND to use about twice as much as where you set your limits. Hmm, looking into the code again, I realized my memory was slightly incorrect: cleaning interval has been effectively no-op since BIND 9.5 should have been cleaning interval has been effectively meaningless and therefore disabled by default since BIND 9.5, and if you explicitly enable it by setting cleaning-interval to a non 0 value, it will still do meaningless but expensive operations. So, in conclusion, my main point should still stand: Tweaking it (cleaning-interval) won't improve performance. And, it could actually do harm. Thanks, I learned something today! But that sort of prompts the question in my mind, why does the option still exist? Good question, I wonder the same thing:-) I don't remember the original plan, but I guess it was actually planned to be deprecated but it has just been forgotten or left as a lower priority thing since then. --- JINMEI, Tatuya Internet Systems Consortium, Inc. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On 6/5/2012 11:30 AM, JINMEI Tatuya / 神明達哉 wrote: Good question, I wonder the same thing:-) I don't remember the original plan, but I guess it was actually planned to be deprecated but it has just been forgotten or left as a lower priority thing since then. So, get busy! It's not like you have nothing else to do ... :) Doug -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
-Original Message- From: Doug Barton do...@dougbarton.us Organization: http://SupersetSolutions.com/ Date: Tuesday, June 5, 2012 11:49 AM To: JINMEI Tatuya / 神明達哉 jin...@isc.org Cc: comp-protocols-dns-b...@isc.org Subject: Re: Recommended value for max-cache-size for cache-only shared hosts.. On 6/5/2012 11:30 AM, JINMEI Tatuya / 神明達哉 wrote: Good question, I wonder the same thing:-) I don't remember the original plan, but I guess it was actually planned to be deprecated but it has just been forgotten or left as a lower priority thing since then. So, get busy! It's not like you have nothing else to do ... :) sorry to waste bandwidth, but just wanted to point out this statement is more true than expected in jest...with the double negative (nothing vs anything). i hate english... ;-) ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
At Fri, 1 Jun 2012 21:14:06 +, Dan Mason danma...@qwest.net wrote: cleaning interval has been effectively no-op since BIND 9.5. Tweaking it won't improve performance, although it shouldn't cause a bad effect either. If your cache is too small the CPU will peg when the cleaning-interval goes. Maybe that's changed but the behavior still exists in the 9.7 branch. Setting your cache size really depends on your query load. On a resolver doing 15,000/qps having a cache of 256M will cause a problem during the cleaning-interval whereas if it's 2G you won't notice the interval at all. Also on a busy resolver expect BIND to use about twice as much as where you set your limits. Hmm, looking into the code again, I realized my memory was slightly incorrect: cleaning interval has been effectively no-op since BIND 9.5 should have been cleaning interval has been effectively meaningless and therefore disabled by default since BIND 9.5, and if you explicitly enable it by setting cleaning-interval to a non 0 value, it will still do meaningless but expensive operations. So, in conclusion, my main point should still stand: Tweaking it (cleaning-interval) won't improve performance. And, it could actually do harm. --- JINMEI, Tatuya Internet Systems Consortium, Inc. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On 06/04/2012 11:36, JINMEI Tatuya / 神明達哉 wrote: At Fri, 1 Jun 2012 21:14:06 +, Dan Mason danma...@qwest.net wrote: cleaning interval has been effectively no-op since BIND 9.5. Tweaking it won't improve performance, although it shouldn't cause a bad effect either. If your cache is too small the CPU will peg when the cleaning-interval goes. Maybe that's changed but the behavior still exists in the 9.7 branch. Setting your cache size really depends on your query load. On a resolver doing 15,000/qps having a cache of 256M will cause a problem during the cleaning-interval whereas if it's 2G you won't notice the interval at all. Also on a busy resolver expect BIND to use about twice as much as where you set your limits. Hmm, looking into the code again, I realized my memory was slightly incorrect: cleaning interval has been effectively no-op since BIND 9.5 should have been cleaning interval has been effectively meaningless and therefore disabled by default since BIND 9.5, and if you explicitly enable it by setting cleaning-interval to a non 0 value, it will still do meaningless but expensive operations. So, in conclusion, my main point should still stand: Tweaking it (cleaning-interval) won't improve performance. And, it could actually do harm. Thanks, I learned something today! But that sort of prompts the question in my mind, why does the option still exist? Doug -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
It's really something you'll have to set, and monitor. I'd start with 1 GB, and see how close it gets to that in (say) a week. If it takes a few hours, you might need to go up to 2 or 4, and see how that works. It may never hit the memory limit. Also note that there is 10% to 20% overhead, so if you set a 1 GB limit, it's really more like a 1.1GB to 1.2GB limit. This is because the cache is not the only thing that uses memory, of course, and the limit is only for the cache. Remember that the cache is only used as a cache, and is not required for operation. Technically, BIND 9 could run with a very, very small cache. The default of 32 MB is actually a fairly new thing. It used to be unlimited, but that means BIND will hit some operating system imposed limit, and that is more painful than self-management. --Michael On Jun 1, 2012, at 12:26 AM, blr maani wrote: Doug, hmmm.. 75%-85% seems too large because the host runs email application in addition to cache-and-forward-only BIND (for better local caching). So, I was wondering if there are any best/proven practice/recommendations for such shared application hosts ? The default value is 32MB. We have 8GB RAM. I don't know if its better to start with 1GB (1/8th of RAM)? thanks blr On Thu, May 31, 2012 at 8:17 PM, Michael Graff mgr...@isc.org wrote: Hmm, I don't quite think this is a good idea. BIND 9 (since 9.5) manages memory quite well, but it will happily consume all you have and go into swap. I'd set it high enough (on a dedicated machine) to use plenty of RAM, but low enough to not cause other OS components to swap out or BIND itself to swap. 75% or 85% range seems like a good starting point. --Michael On May 31, 2012, at 8:18 PM, Doug Barton wrote: On 5/31/2012 1:51 PM, blrmaani wrote: Question: what is the recommended configuration for 'max-cache-size' for optimum usage ? You should not restrict the size of the cache at all if you want the best performance. BIND will use as much memory as it needs in order to satisfy the requests of your users. -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On 05/31/2012 22:26, blr maani wrote: Doug, hmmm.. 75%-85% seems too large because the host runs email application in addition to cache-and-forward-only BIND (for better local caching). So get more RAM, or split your services onto multiple systems. Yes, I realize that may not be possible for financial reasons, but you asked about *optimum* performance. The cache is there for a reason. One thing that can help is to set the cleaning interval more aggressively, but that can also cause performance problems for your clients if you are CPU bound, so use that option with care, and monitor the results after a change. So, I was wondering if there are any best/proven practice/recommendations for such shared application hosts ? Yes, don't do that. :) Doug -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On Jun 1 2012, Michael Graff wrote: [...] The default of 32 MB is actually a fairly new thing. Surely the default went back to 0 (effectively unlimited) long ago? 2253. [func] max-cache-size defaults to 32M. max-acache-size defaults to 16M. got into BIND 9.5.0, but 2457. [tuning]max-cache-size is reverted to 0, the previous default. It should be safe because expired cache entries are also purged. [RT #18684] was there before 9.5.1, and AFAICS it has been like that ever since. -- Chris Thompson Email: c...@cam.ac.uk ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On 31.05.12 22:26, blr maani wrote: hmmm.. 75%-85% seems too large because the host runs email application in addition to cache-and-forward-only BIND (for better local caching). So, I was wondering if there are any best/proven practice/recommendations for such shared application hosts ? The default value is 32MB. We have 8GB RAM. I don't know if its better to start with 1GB (1/8th of RAM)? I was thinking of this when the default was changed to 32M. I changed it intentionally to 0 to see how much will memory usage grow. I can tell you that on one of our servers where named uses most memory, it currently uses 1359868 VSZ and 732852 RSS after 38 days with ~432 queries per second. I have even increased max-ttl and max-negative-ttl to see if it affects memory usage. -- Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. Chernobyl was an Windows 95 beta test site. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
At Fri, 01 Jun 2012 03:27:22 -0700, Doug Barton do...@dougbarton.us wrote: One thing that can help is to set the cleaning interval more aggressively, but that can also cause performance problems for your clients if you are CPU bound, so use that option with care, and monitor the results after a change. cleaning interval has been effectively no-op since BIND 9.5. Tweaking it won't improve performance, although it shouldn't cause a bad effect either. --- JINMEI, Tatuya Internet Systems Consortium, Inc. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On Fri, Jun 01, 2012 at 01:11:48PM -0700, JINMEI Tatuya / ?$B?@L@C#:H wrote: At Fri, 01 Jun 2012 03:27:22 -0700, cleaning interval has been effectively no-op since BIND 9.5. Tweaking it won't improve performance, although it shouldn't cause a bad effect either. If your cache is too small the CPU will peg when the cleaning-interval goes. Maybe that's changed but the behavior still exists in the 9.7 branch. Setting your cache size really depends on your query load. On a resolver doing 15,000/qps having a cache of 256M will cause a problem during the cleaning-interval whereas if it's 2G you won't notice the interval at all. Also on a busy resolver expect BIND to use about twice as much as where you set your limits. Dan -- Daniel Mason Senior Engineer CenturyLink, Inc. Internal Use Only - Disclose and distribute only to CenturyLink employees and authorized persons working for CenturyLink. Disclosure outside of CenturyLink is prohibited without authorization. ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Recommended value for max-cache-size for cache-only shared hosts..
We are planning to use cache-only BIND configuration on our hosts. These hosts are shared hosts i.e BIND runs along with other applications on these hosts. RAM size on these hosts = 8GB and hard- disk size=500GB. Question: what is the recommended configuration for 'max-cache-size' for optimum usage ? I was thinking to use the default value of 32M.. any suggestions.. thanks blr ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
On 5/31/2012 1:51 PM, blrmaani wrote: Question: what is the recommended configuration for 'max-cache-size' for optimum usage ? You should not restrict the size of the cache at all if you want the best performance. BIND will use as much memory as it needs in order to satisfy the requests of your users. -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
Hmm, I don't quite think this is a good idea. BIND 9 (since 9.5) manages memory quite well, but it will happily consume all you have and go into swap. I'd set it high enough (on a dedicated machine) to use plenty of RAM, but low enough to not cause other OS components to swap out or BIND itself to swap. 75% or 85% range seems like a good starting point. --Michael On May 31, 2012, at 8:18 PM, Doug Barton wrote: On 5/31/2012 1:51 PM, blrmaani wrote: Question: what is the recommended configuration for 'max-cache-size' for optimum usage ? You should not restrict the size of the cache at all if you want the best performance. BIND will use as much memory as it needs in order to satisfy the requests of your users. -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Recommended value for max-cache-size for cache-only shared hosts..
Doug, hmmm.. 75%-85% seems too large because the host runs email application in addition to cache-and-forward-only BIND (for better local caching). So, I was wondering if there are any best/proven practice/recommendations for such shared application hosts ? The default value is 32MB. We have 8GB RAM. I don't know if its better to start with 1GB (1/8th of RAM)? thanks blr On Thu, May 31, 2012 at 8:17 PM, Michael Graff mgr...@isc.org wrote: Hmm, I don't quite think this is a good idea. BIND 9 (since 9.5) manages memory quite well, but it will happily consume all you have and go into swap. I'd set it high enough (on a dedicated machine) to use plenty of RAM, but low enough to not cause other OS components to swap out or BIND itself to swap. 75% or 85% range seems like a good starting point. --Michael On May 31, 2012, at 8:18 PM, Doug Barton wrote: On 5/31/2012 1:51 PM, blrmaani wrote: Question: what is the recommended configuration for 'max-cache-size' for optimum usage ? You should not restrict the size of the cache at all if you want the best performance. BIND will use as much memory as it needs in order to satisfy the requests of your users. -- If you're never wrong, you're not trying hard enough ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
