Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-24 Thread Edward Capriolo
Haha Ok. It is not a total waste, but practically your time is better spent in other places. The problem is just about everything is a moving target, schema, request rate, hardware. Generally tuning nudges a couple variables in one direction or the other and you see some decent returns. But each

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-24 Thread Peter Schuller
It is not a total waste, but practically your time is better spent in other places. The problem is just about everything is a moving target, schema, request rate, hardware. Generally tuning nudges a couple variables in one direction or the other and you see some decent returns. But each nudge

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-15 Thread Edward Capriolo
Generally tuning the garbage collector is a waste of time. Just follow someone else's recommendation and use that. The problem with tuning is that workloads change then you have to tune again and again. New garbage collectors come out and you have to tune again and again. Someone at your company

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-15 Thread Peter Schuller
Generally tuning the garbage collector is a waste of time. Sorry, that's BS. It can be absolutely critical, when done right, and only useless when done wrong. There's a spectrum in between. Just follow someone else's recommendation and use that. No, don't. Most recommendations out there are

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-12 Thread Peter Schuller
Relatedly, I'd love to learn how to reliably reproduce full GC pauses on C* 1.1+. Our full gc:s are typically not very frequent. Few days or even weeks in between, depending on cluster. But it happens on several clusters; I'm guessing most (but I haven't done a systematic analysis). The only

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-12 Thread Peter Schuller
I was able to run IBM Java 7 with Cassandra (could not do it with 1.6 because of snappy). It has a new Garbage collection policy (called balanced) that is good for very large heap size (over 8 GB), documented here that is so promising with Cassandra. I have not tried it but I like to see how

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-12 Thread Peter Schuller
Our full gc:s are typically not very frequent. Few days or even weeks in between, depending on cluster. *PER NODE* that is. On a cluster of hundreds of nodes, that's pretty often (and all it takes is a single node). -- / Peter Schuller (@scode, http://worldmodscode.wordpress.com)

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-11 Thread Jonathan Ellis
Relatedly, I'd love to learn how to reliably reproduce full GC pauses on C* 1.1+. On Mon, Sep 10, 2012 at 12:37 PM, Oleg Dulin oleg.du...@gmail.com wrote: I am currently profiling a Cassandra 1.1.1 set up using G1 and JVM 7. It is my feeble attempt to reduce Full GC pauses. Has anyone had

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-11 Thread Shahryar Sedghi
I was able to run IBM Java 7 with Cassandra (could not do it with 1.6 because of snappy). It has a new Garbage collection policy (called balanced) that is good for very large heap size (over 8 GB), documented

JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-10 Thread Oleg Dulin
I am currently profiling a Cassandra 1.1.1 set up using G1 and JVM 7. It is my feeble attempt to reduce Full GC pauses. Has anyone had any experience with this ? Anyone tried it ? -- Regards, Oleg Dulin NYC Java Big Data Engineer http://www.olegdulin.com/

Re: JVM 7, Cass 1.1.1 and G1 garbage collector

2012-09-10 Thread Peter Schuller
I am currently profiling a Cassandra 1.1.1 set up using G1 and JVM 7. It is my feeble attempt to reduce Full GC pauses. Has anyone had any experience with this ? Anyone tried it ? Have tried; for some workloads it's looking promising. This is without key cache and row cache and with a pretty