Yeah reboot is working fine. Now I get the uncached time again with it. But rebooting takes so many time and I have to reconnect again and again via shell.
I also tried sync. But when I type it nothing happens. Also searched for a way to use it, but it seems that noone has a good solution there. Docker and vagrant I never tried, but sounds like a good solution. And btw I know that this test here might not be the very best. But since Neo4j does not kill the cache I have to do it this way. Otherwhise I cannot compare it to my other database. The one is clearing cache by shutdown. That's how it should be I think. Thanks Michael Am Donnerstag, 20. November 2014 11:54:24 UTC+1 schrieb Michael Hunger: > > As this is *operating system caches* we're talking about, you can try > "sync" on unix. > > Or reboot. > > It might also work to run Neo4j in a container (docker, vagrant) and > restart / resume that container. > > On Thu, Nov 20, 2014 at 9:29 AM, 'Curtis Mosters' via Neo4j < > [email protected] <javascript:>> wrote: > >> Yeah but the issue is that I have 10 comparisons. Each having let's say >> the 10 same words to search for. >> >> So after the first search Neo4j already knows where they are and is >> faster now. That's the issue I have. Real word is something else, where you >> would change those words. But I don't want to think always about new words >> to search for. >> >> So clearing cache would be way better. IS there really no way to do it? >> >> Also tried* killall -9 java*, but not working. >> Also followed On linux, see: http://linux-mm.org/Drop_Caches >> <http://www.google.com/url?q=http%3A%2F%2Flinux-mm.org%2FDrop_Caches&sa=D&sntz=1&usg=AFQjCNGlvcLH54xciQ5X723RMpzCoWQfBg> >> >> but nothing happens? >> >> Am Mittwoch, 19. November 2014 22:55:23 UTC+1 schrieb Michael Hunger: >>> >>> But for realistic use-cases you will have exactly that setup, that you >>> have hot data in your OS' file-system and also database caches, >>> >>> that is the state you want to reach for real benchmarks as this >>> represents the real world usage, not the cold caches after a computer and >>> database start. >>> >>> The cold cache numbers can be completely ignored imho as they only >>> measure the speed of the disk and the loading mechanism of the FS and >>> database to get data loaded. >>> >>> Same goes for JVM JIT and other optimizations that happen behind the >>> scenes (by OS, JVM, DB) >>> >>> Michael >>> >>> On Wed, Nov 19, 2014 at 9:37 PM, Jacob Hansson <[email protected]> >>> wrote: >>> >>>> Hey mate, >>>> >>>> yeah, this does clarify it. It is very likely that what is happening is >>>> that the OS is caching the index files in RAM, so the second time you run >>>> the database (even after a restart), it does not have to hit disk. You >>>> could verify that this is the case by evicting the OS page cache between >>>> your benchmarks. What OS are you using? >>>> >>>> On linux, see: http://linux-mm.org/Drop_Caches >>>> On mac, you should be able to run 'purge' to clear the caches, see: >>>> http://www.cnet.com/news/purge-the-os-x-disk-cache-to- >>>> analyze-memory-usage/ >>>> >>>> For windows there does not seem to be a vendor-provided mechanism to do >>>> this, see here for alternatives: http://stackoverflow.com/questions/ >>>> 7405868/how-to-invalidate-the-file-system-cache >>>> >>>> /jake >>>> >>>> On Wed, Nov 19, 2014 at 12:25 PM, 'Curtis Mosters' via Neo4j < >>>> [email protected]> wrote: >>>> >>>>> Hi Jacob, well yeah here is an example: >>>>> >>>>> START n=node:titles("title:solar") RETURN count(*) >>>>> >>>>> If I do this right after the import. It needs *180 sec*. But doing >>>>> this a second time needs *3 sec* and after that again just needs 1,5 >>>>> sec, but after that there is no more improvement. Also after doing some >>>>> stuff in the settings, I never get to the 180 sec again.=/ >>>>> >>>>> But if you think now it is just that word. No it's not. Also tested 9 >>>>> others and here it was lasting round about 60 sec, too. But searching >>>>> again >>>>> on them was 1-2 sec. >>>>> >>>>> Also after restarting the Neo4j server it is still that fast (1-3 >>>>> sec). And yeah I need the uncached result time for my comparison. It is >>>>> not >>>>> correct if I continue now with cached things. >>>>> >>>>> Maybe now it's way clearer? If not just let me know. Thank you. >>>>> >>>>> Am Mittwoch, 19. November 2014 18:35:38 UTC+1 schrieb Jacob Hansson: >>>>>> >>>>>> Curtis, >>>>>> >>>>>> can you clarify what you mean by caching, and how you are determining >>>>>> that things are getting cached? >>>>>> >>>>>> If you are talking about caching of the actual data, note that there >>>>>> are several layers of caching - the OS will cache files in its page >>>>>> cache, >>>>>> for instance. If you want to work around that in your testing you need >>>>>> to >>>>>> ask the operating system to flush its caches. >>>>>> >>>>>> /j >>>>>> >>>>>> On Wed, Nov 19, 2014 at 7:36 AM, 'Curtis Mosters' via Neo4j < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Well for my Benchmark I need a clear Cache because otherwhise Neo4j >>>>>>> is always caching and faking my results in a bad way. >>>>>>> >>>>>>> So I tried: >>>>>>> cache_type=none >>>>>>> cache.memory_ratio=0.0 >>>>>>> >>>>>>> >>>>>>> >>>>>>> in the neo4j.properties. Had no real impact still caching. >>>>>>> >>>>>>> Also found something from Michael with jconsole: >>>>>>> http://stackoverflow.com/questions/26189351/neo4j-server- >>>>>>> clear-the-cache-in-ram >>>>>>> But really no idea what he means. =( I meant the JMX call I found >>>>>>> http://stackoverflow.com/questions/12621963/clear-ehcache- >>>>>>> of-remote-server >>>>>>> But also not sure if it is the right thing to clear. >>>>>>> >>>>>>> Here I found infos about the caching: http://neo4j.com/docs/stable/c >>>>>>> onfiguration-caches.html >>>>>>> But nothing worked or was in my mind useful to test. >>>>>>> >>>>>>> Then I gone through all settings here: http://neo4j.com/docs/stable/ >>>>>>> kernel-configuration.html >>>>>>> But yeah except the two lines above nothing looking satisfying. Even >>>>>>> tried query_cache_size=0 but here I got a funny error message then, so >>>>>>> yeah >>>>>>> dunno what that setting means. >>>>>>> >>>>>>> Then I was thinking that setting the neo_mapping stuff to 0 might >>>>>>> help. But then I found http://grokbase.com/t/gg/neo4j >>>>>>> /1312y592r4/caching-the-whole-graph which says that setting to 0 is >>>>>>> like limiting to infinity. >>>>>>> >>>>>>> Ohman so nothing worked to disable the cache. Why is it so hard to >>>>>>> give a setting disable cache or clearing the cache after server is shut >>>>>>> down. >>>>>>> >>>>>>> Really need this =/ >>>>>>> >>>>>>> Thank you >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Neo4j" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to [email protected]. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Neo4j" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Neo4j" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Neo4j" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Neo4j" group. 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