Good question, not sure about that.

Indexing uses lucene behind the scenes, and adds some overhead.

Michael

Am 17.01.2014 um 02:42 schrieb Bill Scheidel <[email protected]>:

> So does that mean multiple fsync operations are done? I'm trying to figure 
> out what would cause the extra 110ms of delay between no indexing and 
> indexing one property.
> 
> On Thursday, January 16, 2014 5:39:32 PM UTC-8, Michael Hunger wrote:
> Because it is transactional.
> 
> So during your tx whenever things are changed / created that correspond to 
> the configured auto-indexing properties they are written to the index.
> 
> Michael
> 
> Am 17.01.2014 um 02:35 schrieb Bill Scheidel <[email protected]>:
> 
>> Hmm... turning off node_auto_indexing drops it from 150ms to 40ms.  Why 
>> would auto indexing block a request?
>> 
>> On Thursday, January 16, 2014 5:07:48 PM UTC-8, Bill Scheidel wrote:
>> My hdparm results are 118 MB/sec which isn't horrible, but it seems like 
>> disk latency is the only thing that matters.  I guess I'll try going back to 
>> the stock settings and moving it over to an SSD and see what happens.
>> 
>> On Thursday, January 16, 2014 4:34:30 PM UTC-8, Wes Freeman wrote:
>> My macbook's virtualbox (running centos) got good results too (99% <20ms, 
>> 50% <7ms). Was hoping for some weirdness. It is running on an ssd (vintage 
>> 2011 macbook pro 13"), hdparm 250MB/sec, so not a great comparison. Only has 
>> 800MB allocated for the VM RAM, using Neo4j stock settings.
>> 
>> Wes
>> 
>> On Thu, Jan 16, 2014 at 7:08 PM, Bill Scheidel <[email protected]> wrote:
>> Yeah, definitely not great.  Odd though since I never had a problem when 
>> working with Postgres or Mongo and they force things to disk as well.  Never 
>> had local requests take more than a couple of ms and then I switch over to 
>> Neo4j and its almost unusable.  There are no flags to change the behavior 
>> for dev/test machines?
>> 
>> 
>> On Thursday, January 16, 2014 4:00:10 PM UTC-8, Michael Hunger wrote:
>> Not so good latency during the test, or? 
>> 
>> Here is my ioping (cool never heard of that one, nice tool). 
>> 
>> w/o ab 
>> --- /tmp/ (hfs /dev/disk0s2) ioping statistics --- 
>> 11 requests completed in 10.2 s, 32.1 k iops, 125.3 mb/s 
>> min/avg/max/mdev = 21 us / 31 us / 50 us / 7 us 
>> 
>> w ab 
>> 29 requests completed in 29.0 s, 33.1 k iops, 129.3 mb/s 
>> min/avg/max/mdev = 20 us / 30 us / 109 us / 17 us 
>> 
>> Am 17.01.2014 um 00:54 schrieb Bill Scheidel <[email protected]>: 
>> 
>> > And this is ioping without the ab test running: 
>> > 
>> > 31 requests completed in 30.5 s, 3.2 k iops, 12.5 mb/s 
>> > min/avg/max/mdev = 190 us / 312 us / 477 us / 63 us 
>> > 
>> > On Thursday, January 16, 2014 3:51:32 PM UTC-8, Bill Scheidel wrote: 
>> > I ran vmstat while running the ab test: 
>> > 
>> > procs -----------memory---------- ---swap-- -----io---- -system-- 
>> > ----cpu---- 
>> >  r  b   swpd   free   buff  cache   si   so    bi    bo   in  cs  us  sy 
>> > id wa 
>> >  0  1      0 2429284 161572 2133284    0    0    22    75   98  354  9  8 
>> > 80  2 
>> > 
>> > I also ran ioping to check disk latency while the ab test was running:   
>> > 
>> > 190 requests completed in 3.3 min, 37 iops, 151.9 kb/s 
>> > min/avg/max/mdev = 192 us / 26.3 ms / 178.1 ms / 26.5 ms 
>> > 
>> > Results from the ab run: 
>> > 
>> > Percentage of the requests served within a certain time (ms) 
>> >   50%    150 
>> >   66%    158 
>> >   75%    166 
>> >   80%    168 
>> >   90%    209 
>> >   95%    276 
>> >   98%    300 
>> >   99%    324 
>> >  100%    366 (longest request) 
>> > 
>> > 
>> > 
>> > On Thursday, January 16, 2014 3:33:55 PM UTC-8, Michael Hunger wrote: 
>> > Let's continue this discussion here. 
>> > 
>> > To collect the other information so far: 
>> > http://stackoverflow.com/questions/21145723/neo4j-2-0-0-poor-performance-for-dev-test-in-a-virtual-machine
>> >  
>> > The GH issue you raised with Wes' and my answers: 
>> > https://github.com/neo4j/neo4j/issues/1829 
>> > 
>> > My "ab" tests: https://gist.github.com/jexp/8452037 
>> > Wes' numbers: 
>> > https://github.com/neo4j/neo4j/issues/1829#issuecomment-32564561 
>> > 
>> > Your messages.log looks good to me. 
>> > 
>> > So it might be related to disk performance, could you run vmstat or 
>> > similar while running the ab test? 
>> > 
>> > I think it is related to the forced fsync at commit which can be hit by a 
>> > higher disk latency? 
>> > 
>> > Michael 
>> > 
>> > -- 
>> > 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/groups/opt_out. 
>> 
>> 
>> -- 
>> 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/groups/opt_out.
>> 
>> 
>> -- 
>> 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/groups/opt_out.
> 
> 
> -- 
> 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/groups/opt_out.

-- 
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/groups/opt_out.

Reply via email to