Re: Regular NullPointerExceptions from `nodetool compactionstats` on 3.7 node

Typically have seen that in the past when the node is overloaded. Is that a possibility for you? If it works consistently after restarting C* it's likely the issue. On 20 April 2018 at 19:27, Paul Pollack wrote: > Hi all, > > We have a cluster running on Cassandra 3.7 (we already know this is >

Re: what's the read cl of list read-on-write operations?

> ​Given the rf is 3, r/w cl is quorum. > Initially, the list is empty, the user appends one element into the list: > list += [foo] > Then node A is down, and the user prepends another element: list = [bar] + list Then A comes back, assuming the list on A is still [foo], and the list on nodeB an

Re: Does Cassandra supports ACID txn

If ACID is needed, then C* is the wrong architecture. Your architecture needs to match to your business processes as Ben pointed out: "Ask if it’s really needed" There is a concept of a velocity file (modern tech is memSQL'ish) that delivers the high performance, acid transactions of lambda archit

Re: Does Cassandra supports ACID txn

Would be interested to hear if anyone else has any different approaches but my approaches would be: 1) Ask if it’s really needed - in the example you gave would it really matter that, for a small period of time, the hotel appeared in once kind of search but not another? (Although clearly there are

Re: Does Cassandra supports ACID txn

Correction from previous query Thanks Ben and all experts. I am almost a newbie to NoSQL world and thus I have a very general question how does consumer application of Cassandra/other NoSQL technologies deal with atomicity & other factors when there is need to *de-normalize *data. For example: L

Re: Does Cassandra supports ACID txn

Thanks Ben and all experts. I am almost a newbie to NoSQL world and thus I have a very general question how does consumer application of Cassandra/other NoSQL technologies deal with atomicity & other factors when there is need to normalize data. For example: Let us say I have requirement for quer

Re: Version Upgrade

There's no harm in running it during any upgrade, and I always recommend doing it just to be in the habit. My 2 cents. On Wed, Apr 25, 2018 at 3:39 PM Christophe Schmitz < christo...@instaclustr.com> wrote: > Hi Pranay, > > You only need to upgrade your SSTables when you perform a major Cassandr

Re: Version Upgrade

Hi Pranay, You only need to upgrade your SSTables when you perform a major Cassandra version upgrade, so you don't need to run it for upgrading in the 3.x.x series. One way to check which storage version your SSTables are using is to look at the SSTables name. It is structured as: --.db The versio

Version Upgrade

When is it necessary to upgrade SSTables ?? For a minor upgrade do we need to run upgrade stables?? I knew when we are doing a major upgrade we have to run upgrade sstables so that sstables will be re-written to newer version with additional meta data. But do we need to run upgrade sstables for u

Re: read repair with consistency one

Hi Ben Thanks a lot. From my analysis of the code it looks like you are right. When global read repair kicks in all live endpoints are queried for data, regardless of consistency level. Only EACH_QUORUM is treated differently. Cheers Grzegorz 2018-04-22 1:45 GMT+02:00 Ben Slater : > I haven't

Cassandra downgrade version

Looks like no major table version changes since 3.0, and a couple of minor changes in 3.0.7/3.7 and 3.0.8/3.8: https://github.com/apache/cassandra/blob/48a539142e9e318f9177ad8cec4781 9d1adc3df9/doc/source/architecture/storage_engine.rst So, I suppose whether a revert is safe or not depends on whet

Cassandra reaper metrics

Hi Does the metrics work with prometheus? I did find graphite example ..not sure what would be the prometheus example.

Re: Cassandra Driver Pagination

Hi Ahmed, It does not, it only reads enough rows to satisfy the clients request. Although, that may be a bit of an oversimplification as it has to scan through sstable files, read indices, pass over tombstones and so on, but it will stop reading new rows once it has read the number of rows the dri

Re: Reading Cassandra's Blob from Apache Ignite

I think you’ll have better luck with the ignite list, as this looks like an ignite configuration problem. On Wed, Apr 25, 2018 at 3:09 AM wrote: > Dear Community, > > > > I'm trying to read the contents of Cassandra table from Ignite(acting as > cache). The table is given below:: > > CREATE TABLE

Re: Cassandra Driver Pagination

Hi Andy, Thanks. When the driver requests X rows, C* will load the whole partition (All rows) before reply to driver ? Thanls. 2018-04-24 18:11 GMT+02:00 Andy Tolbert : > Hi Ahmed, > > The java driver docs do a good job explaining how the driver uses paging, > including providing a sequence di