Re: Cassandra p95 latencies

2023-08-10 Thread Shaurya Gupta
The queries are rightly designed as I already explained. 40 ms is way too high as compared to what I seen with other DBs and many a times with Cassandra 3.x versions. CPU consumed as I mentioned is not high, it is around 20%. On Thu, Aug 10, 2023 at 5:14 PM MyWorld wrote: > Hi, > P95 should not

Re: Cassandra p95 latencies

2023-08-10 Thread Abe Ratnofsky
40ms is definitely higher than expected. Have you run your queries with TRACING enabled to see where the latency is coming from?https://docs.datastax.com/en/cql-oss/3.3/cql/cql_reference/cqlshTracing.html40ms is also a fairly specific duration: https://eklitzke.org/the-caveats-of-tcp-nodelay> On

Re: Upgrade from 3.11.5 to 4.1.x

2023-08-10 Thread MyWorld
You can check in your lower environment. On Fri, 11 Aug, 2023, 06:25 Surbhi Gupta, wrote: > Thanks, > > I am looking to to upgrade to 4.1.x . > Please advise. > > Thanks > Surbhi > > On Thu, Aug 10, 2023 at 5:39 PM MyWorld wrote: > >> Though it's recommended to upgrade to latest version of

Re: Upgrade from 3.11.5 to 4.1.x

2023-08-10 Thread Surbhi Gupta
Thanks, I am looking to to upgrade to 4.1.x . Please advise. Thanks Surbhi On Thu, Aug 10, 2023 at 5:39 PM MyWorld wrote: > Though it's recommended to upgrade to latest version of 3.11.x and then to > ver 4 but even upgrading directly won't be a problem. Just check the > release notes. > >

Re: Upgrade from 3.11.5 to 4.1.x

2023-08-10 Thread MyWorld
Though it's recommended to upgrade to latest version of 3.11.x and then to ver 4 but even upgrading directly won't be a problem. Just check the release notes. However for production, I would recommend to go for 4.0.x latest stable version. Regards Ashish On Sat, 8 Jul, 2023, 05:44 Surbhi

Re: Materialized View inconsistency issue

2023-08-10 Thread MyWorld
Hi surbhi , There are 2 drawbacks associated with MV. 1. Inconsistent view 2. The lock it takes on the base table. This gets worse when you have huge number of clustering keys in a specific partition. It's better you re-design a seperate table and let your API do a parallel write on both.

Re: Cassandra p95 latencies

2023-08-10 Thread MyWorld
Hi, P95 should not be a problem if rightly designed. Levelled compaction strategy further reduces this, however it consume some resources. For read, caching is also helpful. Can you check your cpu iowait as it could be the reason for delay Regards, Ashish On Fri, 11 Aug, 2023, 04:58 Shaurya

Cassandra p95 latencies

2023-08-10 Thread Shaurya Gupta
Hi community What is the expected P95 latency for Cassandra Read and Write queries executed with Local_Quorum over a table with 3 replicas ? The queries are done using the partition + clustering key and row size in bytes is not too much, maybe 1-2 KB maximum. Assuming CPU is not a crunch ? We

Re: Materialized View inconsistency issue

2023-08-10 Thread Surbhi Gupta
Thanks everyone. On Wed, 9 Aug 2023 at 01:00, Regis Le Bretonnic wrote: > > Hi Surbhi > > We do use cassandra materialized views even if not recommended. > There are known issues you have to make with. Despite of them, we still use > VM. > What we observe is : > * there are inconsistency