Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-09-08 Thread Ariel Weisberg
t;> in the prevelance of HT and you see a lot of 24+ flush writer >>>> systems in the wild) >>>> >>>> No disrespect intended but that default hasn't worked out well at >>>> all in my exposure to it, and 0.6 has never been worse than the >>

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-09-08 Thread Benedict Elliott Smith
at all in >>> my exposure to it, and 0.6 has never been worse than the default yet. >>> Obviously write patterns, heap configuration, memtable size limits and what >>> not affect the exact optimal setting and I've rarely had it end up 0.6 >>> after a tuning exercise. I nev

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-09-01 Thread Thomas Julian
6 after a tuning exercise. I never intended that as a blanket recommendation, just a starting one. _ From: Benedict Elliott Smith <bened...@apache.org> Sent: Friday, August 26, 2016 9:40 AM Subject: Re: Guidelines for configuring Thresholds for Cassandra met

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-29 Thread Ryan Svihla
Elliott Smith Sent: Friday, August 26, 2016 9:40 AM Subject: Re: Guidelines for configuring Thresholds for Cassandra metrics To: The default when I wrote it was 0.4 but it was found this did not saturate flush writers in JBOD configurations. Iirc it now defaults to 1/(1+#disks) which is not a

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-27 Thread Benedict Elliott Smith
e. I never intended that as a blanket recommendation, > just a starting one. > > _ > From: Benedict Elliott Smith > > Sent: Friday, August 26, 2016 9:40 AM > Subject: Re: Guidelines for configuring Thresholds for Cassandra metrics > To: > > > > The default when I wrote

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-27 Thread Ryan Svihla
etting and I've rarely had it end up 0.6 after a tuning exercise. I never intended that as a blanket recommendation, just a starting one. _ From: Benedict Elliott Smith Sent: Friday, August 26, 2016 9:40 AM Subject: Re: Guidelines for configuring Thre

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-26 Thread Benedict Elliott Smith
The default when I wrote it was 0.4 but it was found this did not saturate flush writers in JBOD configurations. Iirc it now defaults to 1/(1+#disks) which is not a terrible default, but obviously comes out much lower if you have many disks. This smaller value behaves better for peak performance,

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-26 Thread Ryan Svihla
Forgot the most important thing. LogsERROR you should investigateWARN you should have a list of known ones. Use case dependent. Ideally you change configuration accordingly.*PoolCleaner (slab or native) - good indication node is tuned badly if you see a ton of this. Set memtable_cleanup_thresho

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-08-26 Thread Ryan Svihla
Thomas, Not all metrics are KPIs and are only useful when researching a specific issue or after a use case specific threshold has been set. The main "canaries" I monitor are:* Pending compactions (dependent on the compaction strategy chosen but 1000 is a sign of severe issues in all cases)* drop

Guidelines for configuring Thresholds for Cassandra metrics

2016-08-26 Thread Thomas Julian
Hello, I am working on setting up a monitoring tool to monitor Cassandra Instances. Are there any wikis which specifies optimum value for each Cassandra KPIs? For instance, I am not sure, What value of "Memtable Columns Count" can be considered as "Normal". What value of the same has to be