Running cassandra

Hi anyone, I am trying to get started to play with Cassandra follow this doc: http://cassandra.apache.org/doc/latest/getting_started/installing.html#prerequisites But I always get the error: qlong@~/ws/cas/apache-cassandra-3.10 $ ./bin/cassandra -f Java HotSpot(TM) 64-Bit Server VM warning:

Re: How can I scale my read rate?

Forgot to mention that this vmstat picture is for the client-cluster reading from Cassandra. On Sat, Mar 18, 2017 at 6:47 PM, S G wrote: > ok, I gave the executeAsync() a try. > Good part is that it was really easy to write the code for that. > Bad part is that it did

Re: How can I scale my read rate?

ok, I gave the executeAsync() a try. Good part is that it was really easy to write the code for that. Bad part is that it did not had a huge effect on my throughput - I gained about 5% increase in throughput. I suspect it is so because my queries are all get-by-primary-key queries and were anyways

Re: How can I scale my read rate?

Thanks. It seems that you guys have found executeAsync to yield good results. I want to share my understanding how this could benefit performance and some validation from the group will be awesome. I will call executeAsync() each time I want to get by primary-key. That ways, my client thread is

AW: How can I scale my read rate?

+1 for executeAsync – had a long time to argue that it’s not bad as with good old rdbms. Gesendet von meinem Windows 10 Phone Von: Arvydas Jonusonis Gesendet: Samstag, 18. März 2017 19:08 An: user@cassandra.apache.org Betreff: Re: How can I scale my read rate? ..then you're not taking

Re: Grouping time series data into blocks of times

If its a sliding 30 min window you will need to implement it and have an in-memory timestamp list but out of order messages will always be a headache. If you are ok with a fixed 30 min window (each 30 min eg 5:00, 5:30, 6:00,..) then just add a time bucket into the partition key and you are done.

Grouping time series data into blocks of times

I have a use case where a stream of time series data is coming in. Each item in the stream has a timestamp of when it was sent, and covers the activity that happened within a 5 minute timespan. I need to group the items together into 30 minute blocks of time. E.g, say I receive the following

Re: repair performance

You changed compaction_throughput_mb_per_sec, but did you also increase concurrent_compactors? In reference to the reaper and some other info I received on the user forum to my question on "nodetool repair", here are some useful links/slides -

Corrupt SSTable after dropping column

Hi, It seems like dropping a column can cause a "java.io.IOException: Corrupt empty row found in unfiltered partition" exception when existing SSTables are later compacted. This seems to happen with all Cassandra 3.x versions and is very easy to replicate. I've created a jira with all the