Re: Too many Cassandra threads waiting!!!

2018-08-02 Thread Joshua Galbraith
Renoy, Thanks. That kernel is new enough to have the patch for the infamous Linux kernel futex bug detailed here: https://groups.google.com/d/topic/mechanical-sympathy/QbmpZxp6C64 To answer your questions above: What you're seeing is likely just normal behavior for Cassandra and is an artifact o

Re: Too many Cassandra threads waiting!!!

2018-08-02 Thread nokia ceph
Hi Joshua, # uname -a Linux cn6.chn6us1c1.cdn 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux # cat /etc/redhat-release CentOS Linux release 7.4.1708 (Core) On Fri, Aug 3, 2018 at 8:27 AM, Joshua Galbraith < jgalbra...@newrelic.com.invalid> wrote: > Renoy

Re: Too many Cassandra threads waiting!!!

2018-08-02 Thread Joshua Galbraith
Renoy, Out of curiosity, which kernel version are your nodes running? You may find this old message on the mailing list helpful: http://mail-archives.apache.org/mod_mbox/cassandra-user/201602.mbox/%3CCAA=6j0-0vabfan3djfatoxyjwwehpdie67v2wm_u5kaqoro...@mail.gmail.com%3E On Wed, Aug 1, 2018 at 5:3

Re: Performance impact of using NetworkTopology with 3 node cassandra cluster in One DC

2018-08-02 Thread Kyrylo Lebediev
There are two factors in terms of Cassandra that determine what's called network topology: datacenter and rack. rack - it's not necessarily a physical rack, it's rather a single point of failure. For example, in case of AWS one availability zone is usually chosen to be a Cassandra rack. datace

Performance impact of using NetworkTopology with 3 node cassandra cluster in One DC

2018-08-02 Thread Murtaza Talwari
We are using 3 node Cassandra cluster in one data center. For our keyspaces as suggested in best practices we are using NetworkTopology for replication strategy using the GossipingPropertyFileSnitch. For Read/Write consistency we are using as QUORUM. In majority of cases when users use NetworkTo