Re: Row cache tuning

2017-03-13 Thread Thomas Julian
Hi Matija, ​Leveraging page cache yields good results and if accounted for can provide you with performance increase on read side ​ I would like to leverage the page cache to improve read performance. How this can be done? Best Regards, Julian. On Mon, 13 Mar 2017

How to calculate CPU Utilisation on each node?

2017-01-10 Thread Thomas Julian
Hello, We are using Cassandra 2.1.13. We are calculating node CPU utilization using the below formula, CPUUsage = CPURate / (AvailableProcessors*100) CPURate = (x2-x1)/(t2-t1), where x2 and x1 are the values of the attribute ProcessCpuTime at the time t2 and t1 respectively.

How to throttle up/down compactions without a restart

2016-10-20 Thread Thomas Julian
Hello, I was going through this presentation and the Slide-55 caught my attention. i.e) "Throttled down compactions during high load period, throttled up during low load period" Can we throttle down compactions without a restart? If this can be done, what are all the

Optimising the data model for reads

2016-09-29 Thread Thomas Julian
Hello, I have created a column family for User File Management. CREATE TABLE "UserFile" ("USERID" bigint,"FILEID" text,"FILETYPE" int,"FOLDER_UID" text,"FILEPATHINFO" text,"JSONCOLUMN" text,PRIMARY KEY ("USERID","FILEID")); Sample Entry (4*003,

How to alter the default value for concurrent_compactors

2016-09-20 Thread Thomas Julian
Hello, We have commented out "concurrent_compactors" in our Cassandra 2.1.13 installation. We would like to review this setting, as some issues indicate that the default configuration may affect read/write performance. https://issues.apache.org/jira/browse/CASSANDRA-8787

Optimal value for concurrent_reads for a single NVMe Disk

2016-09-20 Thread Thomas Julian
Hello, We are using Cassandra 2.1.13 with each node having a NVMe disk with the configuration of Total Capacity - 1.2TB, Alloted Capacity - 880GB. We would like to increase the default value of 32 for the param concurrent_reads. But the document says "(Default: 32)note For workloads

Re: Guidelines for configuring Thresholds for Cassandra metrics

2016-09-01 Thread Thomas Julian
when people notice a problem, what did these numbers look like in the minutes, hours and days prior? That's the way to establish the levels consistently. Regards, Ryan Svihla On Fri, Aug 26, 2016 at 4:48 AM -0500, "Thomas Julian" thomasjul...@zoho.com wrote: Hell