Re: Is my cluster normal?

iops for commitlog, so write throughput likely goes up, too.   From: Jonathan Haddad <j...@jonhaddad.com> Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> Date: Thursday, July 7, 2016 at 6:54 PM To: "user@cassandra.apache.org" <user@cassandra.a

Re: Is my cluster normal?

>> >>>>>> >>>>>> >>>>>> A 600G EBS volume only guarantees 1800 iops – if you’re exhausting >>>>>> those on writes, you’re going to suffer on reads. >>>>>> >>>>>> >>>>>>

Re: Is my cluster normal?

>>>>>> EBS iops scale with volume size. >>>>>> >>>>>> >>>>>> >>>>>> A 600G EBS volume only guarantees 1800 iops – if you’re exhausting >>>>>> those on writes, you’re going to suffer on reads

Re: Is my cluster normal?

d probably a good chunk of that allocated to >>>>> heap. Consequently, you have almost no page cache, so your reads are going >>>>> to hit the disk. Your reads being very low is not uncommon if you have no >>>>> page cache – the default settings

Re: Is my cluster normal?

ge cache – the default settings for Cassandra (64k compression chunks) >>>> are really inefficient for small reads served off of disk. If you drop the >>>> compression chunk size (4k, for example), you’ll probably see your read >>>> throughput increase significantly, which will

Re: Is my cluster normal?

ge cache – the default settings for Cassandra (64k compression chunks) >>>> are really inefficient for small reads served off of disk. If you drop the >>>> compression chunk size (4k, for example), you’ll probably see your read >>>> throughput increase significantly, which will

Re: Is my cluster normal?

), you’ll probably see your read >>> throughput increase significantly, which will give you more iops for >>> commitlog, so write throughput likely goes up, too. >>> >>> >>> >>> >>> >>> >>> >>> *From: *Jonatha

Re: Is my cluster normal?

>> commitlog, so write throughput likely goes up, too. >> >> >> >> >> >> >> >> *From: *Jonathan Haddad <j...@jonhaddad.com> >> *Reply-To: *"user@cassandra.apache.org" <user@cassandra.apache.org> >> *Date: *Thursday, Ju

Re: Is my cluster normal?

> *Date: *Thursday, July 7, 2016 at 6:54 PM > *To: *"user@cassandra.apache.org" <user@cassandra.apache.org> > *Subject: *Re: Is my cluster normal? > > > > What's your CPU looking like? If it's low, check your IO with iostat or > dstat. I know some people have u

Re: Is my cluster normal?

Hi Jonathan, The IOs are like below. I am not sure why one node always has a much bigger KB_read/s than other nodes. It seems not good. == avg-cpu: %user %nice %system %iowait %steal %idle 54.78 24.489.350.960.08 10.35 Device:tps

Re: Is my cluster normal?

Those numbers, as I suspected, line up pretty well with your AWS configuration and network latencies within AWS. It is clear that this is a WRITE ONLY test. You might want to do a mixed (e.g. 50% read, 50% write) test for sanity. Note that the test will populate the data BEFORE it begins doing the

Re: Is my cluster normal?

6 at 6:54 PM To: "user@cassandra.apache.org" <user@cassandra.apache.org> Subject: Re: Is my cluster normal? What's your CPU looking like? If it's low, check your IO with iostat or dstat. I know some people have used Ebs and say it's fine but ive been burned too many times. On Th

Re: Is my cluster normal?

What's your CPU looking like? If it's low, check your IO with iostat or dstat. I know some people have used Ebs and say it's fine but ive been burned too many times. On Thu, Jul 7, 2016 at 6:12 PM Yuan Fang wrote: > Hi Riccardo, > > Very low IO-wait. About 0.3%. > No

Re: Is my cluster normal?

Hi Riccardo, Very low IO-wait. About 0.3%. No stolen CPU. It is a casssandra only instance. I did not see any dropped messages. ubuntu@cassandra1:/mnt/data$ nodetool tpstats Pool NameActive Pending Completed Blocked All time blocked MutationStage

Re: Is my cluster normal?

Hi Yuan, You machine instance is 4 vcpus that is 4 threads (not cores!!!), aside from any Cassandra specific discussion a system load of 10 on a 4 threads machine is way too much in my opinion. If that is the running average system load I would look deeper into system details. Is that IO wait? Is

Re: Is my cluster normal?

Thanks Ben! For the post, it seems they got a little better but similar result than i did. Good to know it. I am not sure if a little fine tuning of heap memory will help or not. On Thu, Jul 7, 2016 at 2:58 PM, Ben Slater wrote: > Hi Yuan, > > You might find this

Re: Is my cluster normal?

Hi Ryan, The version of cassandra is 3.0.6 and java version "1.8.0_91" Yuan On Thu, Jul 7, 2016 at 3:11 PM, Ryan Svihla wrote: > what version of cassandra and java? > > Regards, > > Ryan Svihla > > On Jul 7, 2016, at 4:51 PM, Yuan Fang wrote: > >

Re: Is my cluster normal?

what version of cassandra and java? Regards, Ryan Svihla > On Jul 7, 2016, at 4:51 PM, Yuan Fang wrote: > > Yes, here is my stress test result: > Results: > op rate : 12200 [WRITE:12200] > partition rate: 12200 [WRITE:12200] > row rate

Re: Is my cluster normal?

Hi Yuan, You might find this blog post a useful comparison: https://www.instaclustr.com/blog/2016/01/07/multi-data-center-apache-spark-and-apache-cassandra-benchmark/ Although the focus is on Spark and Cassandra and multi-DC there are also some single DC benchmarks of m4.xl clusters plus some

Re: Is my cluster normal?

Yes, here is my stress test result: Results: op rate : 12200 [WRITE:12200] partition rate: 12200 [WRITE:12200] row rate : 12200 [WRITE:12200] latency mean : 16.4 [WRITE:16.4] latency median: 7.1 [WRITE:7.1] latency 95th

Re: Is my cluster normal?

Lots of variables you're leaving out. Depends on write size, if you're using logged batch or not, what consistency level, what RF, if the writes come in bursts, etc, etc. However, that's all sort of moot for determining "normal" really you need a baseline as all those variables end up

Re: Is my cluster normal?

yes, it is about 8k writes per node. On Thu, Jul 7, 2016 at 2:18 PM, daemeon reiydelle wrote: > Are you saying 7k writes per node? or 30k writes per node? > > > *...* > > > > *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198 > <%28%2B1%29%20415.501.0198>London (+44) (0) 20

Re: Is my cluster normal?

Are you saying 7k writes per node? or 30k writes per node? *...* *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198London (+44) (0) 20 8144 9872* On Thu, Jul 7, 2016 at 2:05 PM, Yuan Fang wrote: > writes 30k/second is the main thing. > > > On Thu, Jul 7, 2016 at 1:51

Re: Is my cluster normal?

writes 30k/second is the main thing. On Thu, Jul 7, 2016 at 1:51 PM, daemeon reiydelle wrote: > Assuming you meant 100k, that likely for something with 16mb of storage > (probably way small) where the data is more that 64k hence will not fit > into the row cache. > > >

Re: Is my cluster normal?

Assuming you meant 100k, that likely for something with 16mb of storage (probably way small) where the data is more that 64k hence will not fit into the row cache. *...* *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198London (+44) (0) 20 8144 9872* On Thu, Jul 7, 2016 at 1:25 PM, Yuan Fang

Is my cluster normal?

I have a cluster of 4 m4.xlarge nodes(4 cpus and 16 gb memory and 600GB ssd EBS). I can reach a cluster wide write requests of 30k/second and read request about 100/second. The cluster OS load constantly above 10. Are those normal? Thanks! Best, Yuan