cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Nitsan Wakart (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-15037) cassandra-stress doesn't provide warmup for duration based executions
Date Fri, 01 Mar 2019 07:30:00 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-15037?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16781382#comment-16781382
] 

Nitsan Wakart commented on CASSANDRA-15037:
-------------------------------------------

I have hit this issue in the past, but TBH have never considered fixing it as I moved away
from using the summary result to post processing the HDR histogram files. The solution in my
case has been to use the fixed rate mode with an HDR log file output and select the period
of interest in post processing by HdrLogProcessing ([https://github.com/nitsanw/HdrLogProcessing).] This
method also allows for unifying multiple load generator outputs and trimming away the ramp
up and ramp down periods where load is uneven or the load generators are warming up or the
server is warming up etc.

Having said all that, I think this is a feature worth implementing for those who rely on the
command line output and summary.

 

> cassandra-stress doesn't provide warmup for duration based executions
> ---------------------------------------------------------------------
>
>                 Key: CASSANDRA-15037
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-15037
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Legacy/Tools
>            Reporter: Sergey Kuksenko
>            Priority: Minor
>              Labels: stress
>             Fix For: 4.0.x
>
>         Attachments: stress_warmup.patch
>
>
> cassandra-stress utility performs warmup only when number of operations is specified.
> In case of duration based execution it doesn't provide warmup. That leads to count startup/warmup
induced latency that maybe considered as undesired statistics.
> For example latencies difference between warmed and cold execution even for 15 minutes
may reach to:  17% for 99th percentile, 35% for 99.9th and 55% for max latency.
>  
> Attached patch contains example how it may be fixed. It was chosen to use 1/5 of duration
time as warmup time, but probably the proper way to do it is to add a new option.
>  



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org


Mime
View raw message