cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Laxmikant Upadhyay <>
Subject Re: write latency on single partition table
Date Sat, 07 Apr 2018 04:39:41 GMT
It seems your partition size is more..what is the size of value field ? Try
to keep your partition size within 100 mb.

On Sat, Apr 7, 2018, 9:45 AM onmstester onmstester <>

> I've defained a table like this
> create table test (
> hours int,
> key1 int,
> value1 varchar,
> primary key (hours,key1)
> )
> For one hour every input would be written in single partition, because i
> need to group by some 500K records in the partition for a report with
> expected response time in less than 1 seconds so using key1 in partition
> key would made 500K partitions which would be slow on reads.
> Although using  this mechanism gains < 1 seconds response time on reads
> but the write delay increased surprisingly, for this table write latency
> reported by cfstats is more than 100ms but for other tables which accessing
> thousands of partitions while writing in 1 hour , the write delay is
> 0.02ms. But i was expecting that writes to test table be faster than other
> tables because always only one node and one partition would be accessed, so
> no memtable switch happens and all writes would be local to a single node?!
> Should i add another key to my partition key to distribute data on all of
> nodes?
> Sent using Zoho Mail <>

View raw message