Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

I am not sure I fully understand the question, because nodetool repair is one of the three ways for Cassandra to ensure consistency. If by "affect" you mean "make your data consistent and ensure all replicas are up-to-date", then yes, that's what I think it does. And yes, I would expect nodetool

High cpu usage when the cluster is idle

I saw an average 10% cpu usage on each node when the cassandra cluster has no load at all. I checked which thread was using the cpu, and I got the following 2 metric threads each occupying 5% cpu. jstack output: "metrics-meter-tick-thread-2" daemon prio=10 tic=...

Re:High cpu usage when the cluster is idle

The cassandra version is 2.0.12. We have 1500 tables in the cluster of 6 nodes, with a total 2.5 billion rows. 在2015年10月24 20时52分, "Xu Zhongxing"写道: I saw an average 10% cpu usage on each node when the cassandra cluster has no load at all. I checked which thread was

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Max hint window is only part of the equation. If it is down longer than Max hint window, a repair will still fix up the node for you. The max time a node can be down before it must be re built is determined by the lowest gc grace setting on your various tables. By default gc grace is 10 days,

Re: Is replication possible with already existing data?

Ideas please, on what I may be doing wrong? On Sat, Oct 24, 2015 at 5:48 PM, Ajay Garg wrote: > Hi All. > > I have been doing extensive testing, and replication works fine, even if > any permuatation of CAS11, CAS12, CAS21, CAS22 are downed and brought up. > Syncing

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Never mind Vasileios, you have been a great help !! Thanks a ton again !!! Thanks and Regards, Ajay On Sat, Oct 24, 2015 at 10:17 PM, Vasileios Vlachos < vasileiosvlac...@gmail.com> wrote: > I am not sure I fully understand the question, because nodetool repair is > one of the three ways for

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Thanks a ton Vasileios !! Just one last question :: Does running "nodetool repair" affect the functionality of cluster for current-live data? It's ok if the insertions/deletions of current-live data become a little slow during the process, but data-consistency must be maintained. If that is the

Re: High cpu usage when the cluster is idle

I would imagine you are running on fairly slow machines (given the CPU usage), but 2.0.12 and 2.1 use a fairly old version of the yammer/codehale metrics library. It is waking up every 5 seconds, and updating Meters… there are a bunch of these Meters per table (embedded in Timers), so your

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

On Sat, Oct 24, 2015 at 9:47 AM, Vasileios Vlachos < vasileiosvlac...@gmail.com> wrote: > I am not sure I fully understand the question, because nodetool repair is > one of the three ways for Cassandra to ensure consistency. If by "affect" > you mean "make your data consistent and ensure all

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

> > > All other means of repair are optimizations which require a certain amount > of luck to happen to result in consistency. > Is that true regardless of the CL one uses? So, for example if writing QUORUM and reading QUORUM, wouldn't an increased read_repair_chance probability be sufficient? If

Some questions about setting public/private IP-Addresses in Cassandra Cluster

Hi All. We have a scenario, where the Application-Server (APP), Node-1 (CAS11), and Node-2 (CAS12) are hosted in DC1. Node-3 (CAS21) and Node-4 (CAS22) are in DC2. The intention is that we provide 4-way redundancy to APP, by specifying CAS11, CAS12, CAS21 and CAS22 as the addresses via

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Hello Ajay, Here is a good link: http://docs.datastax.com/en/cassandra/2.1/cassandra/operations/opsRepairNodesManualRepair.html Generally, I find the DataStax docs to be OK. You could consult them for all usual operations etc. Ofc there are occasions where a given concept is not as clear, but

Downtime-Limit for a node in Network-Topology-Replication-Cluster?

If a node in the cluster goes down and comes up, the data gets synced up on this downed node. Is there a limit on the interval for which the node can remain down? Or the data will be synced up even if the node remains down for weeks/months/years? -- Regards, Ajay

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Thanks Vasileios for the reply !!! That makes sense !!! I will be grateful if you could point me to the node-repair command for Cassandra-2.1.10. I don't want to get stuck in a wrong-versioned documentation (already bitten once hard when setting up replication). Thanks again... Thanks and

Re: Downtime-Limit for a node in Network-Topology-Replication-Cluster?

Hello Ajay, Have a look in the *max_hint_window_in_ms* : http://docs.datastax.com/en/cassandra/2.0/cassandra/configuration/configCassandra_yaml_r.html My understanding is that if a node remains down for more than *max_hint_window_in_ms*, then you will need to repair that node. Thanks, Vasilis

Re: Is replication possible with already existing data?

Hi All. I have been doing extensive testing, and replication works fine, even if any permuatation of CAS11, CAS12, CAS21, CAS22 are downed and brought up. Syncing always takes place (obviously, as long as continuous-downtime-value does not exceed *max_hint_window_in_ms*). However, things behave