How to avoid flush if the data can fit into memtable

Hi, I'm running Cassandra with a very small dataset so that the data can exist on memtable only. Below are my configurations: In jvm.options: -Xms4G -Xmx4G In cassandra.yaml, memtable_cleanup_threshold: 0.50 memtable_allocation_type: heap_buffers As per the documentation in cassandra.yaml,

Re: Impact on latency with larger memtable

Thank you all for the response. I figured out the root cause. I thought all my data was in memtable only but the data was actually being dumped to the disk. That's why I was noticing the drop in throughput. On Wed, May 24, 2017 at 9:42 AM, daemeon reiydelle wrote: > You

Re: Replication issue with Multi DC setup in cassandra

Cqlsh looks at the cluster, not node “All men dream, but not equally. Those who dream by night in the dusty recesses of their minds wake up in the day to find it was vanity, but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible.” — T.E.

Re: Replication issue with Multi DC setup in cassandra

Run *nodetool cleanup* on the *4.4.4.5* DC node(s). Changing network topology does not *remove* data - it's a manual task. But it should prevent it from replicating over to the undesired DC. Also make sure your LoadBalancingStrategy is set to DCAwareRoundRobinPolicy, with *4.4.4.4* DC set as the

Re: Replication issue with Multi DC setup in cassandra

May I inquire if your configuration is actually data center aware? Do you understand the difference between LQ and replication? *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198London (+44) (0) 20 8144 9872* *“All men dream, but not equally. Those who dream by night in the dusty recesses of

Re: Replication issue with Multi DC setup in cassandra

Did you run `nodetool repair` after changing the keyspace? (not sure if it makes sense though) 2017-05-16 19:52 GMT-03:00 Nitan Kainth : > Strange. Anybody else might share something more important. > > Sent from my iPhone > > On May 16, 2017, at 5:23 PM, suraj pasuparthy

Re: Impact on latency with larger memtable

You speak of increase. Please provide your results. Specific examples, Eg 25% increase results in n% increase. Also please include number of nodes, size of total keyspace, rep factor, etc. Hopefully this is a 6 node cluster with several hundred gig per keyspace, not some single node free tier

Re: Impact on latency with larger memtable

Larger memtable means mor time during flushes and larger heap means longer GC pauses. You can see these in system log Sent from my iPhone > On May 24, 2017, at 11:31 AM, preetika tyagi wrote: > > Hi, > > I'm experimenting with memtable/heap size on my Cassandra

Impact on latency with larger memtable

Hi, I'm experimenting with memtable/heap size on my Cassandra server to understand how it impacts the latency/throughput for read requests. I vary heap size (Xms and -Xmx) in jvm.options so memtable will be 1/4 of this. When I increase the heap size and hence memtable, I notice the drop in

Re: How to find dataSize at client side?

Hi, The list is opened : https://groups.google.com/a/lists.datastax.com/forum/#!forum/java-driver-user, feel free to subscribe. Datastax is the main maintainer of the java driver, which is open source ( https://github.com/datastax/java-driver ) , which is not the same driver as the DSE one :

Re: How to find dataSize at client side?

Hi Nicolas I think only DataStax Enterprise(paid) c* version can ask questions/get support from datastax :( On Tue, May 23, 2017 at 9:44 PM, techpyaasa . wrote: > Thanks for your reply.. > > On Tue, May 23, 2017 at 7:40 PM, Nicolas Guyomar < > nicolas.guyo...@gmail.com>

Re: Slowness in C* cluster after implementing multiple network interface configuration.

It might be a bug. Cassandra, AFAIK, scans those files for changes and updates the topology (So you don't need a restart if you change the files). It might be the case that the absence of the file, is still noticed by Cassandra even if it is not really used. I can do a small test to confirm, if

RE: Slowness in C* cluster after implementing multiple network interface configuration.

Hi All, We have a new observation. Earlier for implementing multiple network interfaces, we were deleting cassandra-topologies.properties in the last step (Steps are mentioned in mail trail). The rationale was that because we are using altogether a new endpoint_snitch , we don't require

Re: EC2 instance recommendations

Exactly. On 23-05-2017 23:55, Gopal, Dhruva wrote: > > By that do you mean it’s like bootstrapping a node if it fails or is > shutdown and with a RF that is 2 or higher, data will get replicated > when it’s brought up? > > > > *From: *Cogumelos Maravilha > *Date:

Re: memtable_allocation_type on Cassandra 2.1.x

Hi Varun, Look at the recommendation for offheap_objects and memtable flush writers and readers in the following guide https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html. In the guide and cassandra.yaml the default is suggested as a good starting point. If you want to use the