I would expect single digit ms latency on reads and writes. However, we have not done any performance testing on Apache Cassandra 4.x.
Sean R. Durity INTERNAL USE From: Shaurya Gupta <shaurya.n...@gmail.com> Sent: Friday, August 11, 2023 1:16 AM To: user@cassandra.apache.org Subject: [EXTERNAL] Re: Cassandra p95 latencies 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, 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 <timeplus.1...@gmail.com<mailto:timeplus.1...@gmail.com>> wrote: 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 Gupta, <shaurya.n...@gmail.com<mailto:shaurya.n...@gmail.com>> wrote: 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 observe those to be 40 ms P95 Reads and same for Writes. This looks very high as compared to what we expected. We are using Cassandra 4.0. Any documentation / numbers will be helpful. Thanks -- Shaurya Gupta -- Shaurya Gupta ________________________________ The information in this Internet Email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this Email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this Email are subject to the terms and conditions expressed in any applicable governing The Home Depot terms of business or client engagement letter. The Home Depot disclaims all responsibility and liability for the accuracy and content of this attachment and for any damages or losses arising from any inaccuracies, errors, viruses, e.g., worms, trojan horses, etc., or other items of a destructive nature, which may be contained in this attachment and shall not be liable for direct, indirect, consequential or special damages in connection with this e-mail message or its attachment.
