Even after the drop table, the data actually was not erased.

hi everyone On the development server, I dropped all the tables and even keyspace dropped to change the table schema. Then I created the keyspace and the table. However, the actual size of the data directory did not decrease at all. Disk Load monitored by JMX has been decreased. After that,

Re: default_time_to_live setting in time series data

Thanks for the quick response. TWCS is used. > On 12 Jan 2018, at 11:38 AM, Jeff Jirsa wrote: > > Probably not in any measurable way. > > -- > Jeff Jirsa > > >> On Jan 11, 2018, at 6:16 PM, Eunsu Kim wrote: >> >> Hi everyone >> >> We are collecting monitoring data in excess of 100K TPS

Re: default_time_to_live setting in time series data

Probably not in any measurable way. -- Jeff Jirsa > On Jan 11, 2018, at 6:16 PM, Eunsu Kim wrote: > > Hi everyone > > We are collecting monitoring data in excess of 100K TPS in Cassandra. > > All data is time series data and must have a TTL. > > Currently we have set default_time_to_liv

Re: default_time_to_live setting in time series data

No. Nothing measurable. In fact it should be beneficial if paired with TWCS On 12 Jan. 2018 1:17 pm, "Eunsu Kim" wrote: Hi everyone We are collecting monitoring data in excess of 100K TPS in Cassandra. All data is time series data and must have a TTL. Currently we have set default_time_to_liv

default_time_to_live setting in time series data

Hi everyone We are collecting monitoring data in excess of 100K TPS in Cassandra. All data is time series data and must have a TTL. Currently we have set default_time_to_live on the table. Does this have a negative impact on Cassandra throughput performance? Thank you in advance. --

Re: Use Oracle Virtual Machine to Set Up Multiple Node 2 DC cluster

Documentation for Virtual box networking can be found here: https://www.virtualbox.org/manual/ch06.html You can probably achieve what you're set up using two separate internal networks and some custom routing on the Windows 10 host. This question may be better suited for the virtualbox user maili

Use Oracle Virtual Machine to Set Up Multiple Node 2 DC cluster

Hi , Can you please help me to know, how to set up Networks into ORACLE Virtual Box machine by which I can able to achieve multiple DC multiple Node configuration. I am using window 10 as the host machine. I tried to setup using NAT but it is not working. Please provide some idea. Thanks. Nanda

Re: Too many tombstones using TTL

You should be able to avoid querying the tombstones if it's time series data. Using TWCS just make sure you don't query data that you know is expired (assuming you have the time component in your clustering key)​.

Re: C* keyspace layout

Can you elaborate? What interrupt are you referring to? That's a perfectly legitimate topology, it's usefulness depends on your application. On 11 January 2018 at 13:04, Peng Xiao <2535...@qq.com> wrote: > Hi there, > > We plan to set keyspace1 in DC1 and DC2,keyspace2 in DC3 and DC4,all still >

Re: Dropped Mutations

Dropped mutations aren't data loss. Data loss implies the data was already there and is now gone, whereas for a dropped mutation the data was never there in the first place. A dropped mutation just results in a inconsistency, or potentially no data if all mutations are dropped, and C* will tell you

Re: Restoring fresh new cluster from existing snapshot

Hello Jeff, Thank you for the reply. One doubt - If i copy the /var/lib/cassandra one to one from source cluster to destination cluster nodes and change the cluster name in configuration and delete system.peers table and restart each cassandra node, do you think the cluster will come up properly.

Re: Restoring fresh new cluster from existing snapshot

Make sure the new cluster has a different cluster name, and avoid copying system.peers if you can avoid it. Doing so risks merging your new cluster and old cluster if they’re able to reach each other. -- Jeff Jirsa > On Jan 11, 2018, at 1:41 AM, Pradeep Chhetri wrote: > > Thank you very muc

C* keyspace layout

Hi there, We plan to set keyspace1 in DC1 and DC2,keyspace2 in DC3 and DC4,all still in the same cluster,to avoid the interrupt.Is there any potential risk for this architecture? Thanks, Peng Xiao

Re: Restoring fresh new cluster from existing snapshot

Thank you very much Jean. Since i don't have any constraints, as you said, i will try copying the complete keyspace system node by node first and will do nodetool refresh and see if it works. On Thu, Jan 11, 2018 at 3:21 PM, Jean Carlo wrote: > Hello, > > Basically, every node has to have the

Re: Restoring fresh new cluster from existing snapshot

Hello, Basically, every node has to have the same token range. So yes you have to play with initial_token having the same numbers of tokens per node like the cluster source. To save time and if you dont have any constraints about the name of the cluster etc. you can just copy and paste the complet

Re: Restoring fresh new cluster from existing snapshot

Hello Jean, I am running cassandra 3.11.1. Since i dont have much cassandra operations experience yet, I have a follow-up question - how can i ensure the same token ranges distribution ? Do i need to set initial_token configuration for each cassandra node ? Thank you for the quick response.

Re: Restoring fresh new cluster from existing snapshot

Hello Pradeep, Actually the key here is to know if your cluster has the same token ranges distribution. So it is not only the same size but also the same tokens match node by node, from cluster source to cluster destination. In that case, you can use nodetool refresh.So after copy all your sstable

Re: [announce] Release of Cassandra Prometheus metrics exporter

Hello Alain, Thanks for the praise, and be aware that your hardwork has been noticed (at least by us) as we link in the readme toward your post http://thela stpickle.com/blog/2017/12/05/datadog-tlp-dashboards.htmlThanks for having spend time to write it, as I you said creating comprehensive dashboa

Re: Rebuild to a new DC fails every time

Thanks for the tips, Alan. The cluster is entirely healthy. But the connection between DCs is a VPN, managed by a third party - it is possible it might be flaky. However, I would expect the rebuild job to be able to recover from connection timeout/reset type of errors without a need for manual int

Restoring fresh new cluster from existing snapshot

Hello everyone, We are running cassandra cluster inside containers over Kubernetes. We have a requirement where we need to restore a fresh new cluster with existing snapshot on weekly basis. Currently, while doing it manually. i need to copy the snapshot folder inside container and then run sstab

Dropped Mutations

Hello Could the following be interpreted as, 'Dropped Mutations', in some cases mean data loss? http://cassandra.apache.org/doc/latest/faq/index.html#why-message-dropped For writes, this means that the mutation was not applied to all replicas it was sent to. The inconsistency will be repaired by r

High memory usage when running repair with 3.11.1

Hi I'm having a problem after upgrading Cassandra 3.0.14 to 3.11.1. When running a repair the node I'm issuing the repair starts to use use all available memory and then the GC grinds it to death. I'm seeing with nodetool compactionstats that there is a lot of (> 100) active concurrent compaction