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https://issues.apache.org/jira/browse/CASSANDRA-13835?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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C. Scott Andreas updated CASSANDRA-13835:
-----------------------------------------
    Component/s: Core

> Thrift get_slice responds slower on Cassandra 3
> -----------------------------------------------
>
>                 Key: CASSANDRA-13835
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13835
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>         Environment: Windows
>            Reporter: Pawel Szlendak
>            Priority: Major
>         Attachments: 0001-Fix-performance-when-running-on-Windows.patch, 
> attack.py, cassandra120_get_slice_reply_time.png, 
> cassandra310_get_slice_reply_time.png
>
>
> I have recently upgraded from Cassandra 1.2.18 to Cassandra 3.10 and was 
> surprised to notice performance degradation of my server application.
> I dug down through my application stack only to find out that the cause of 
> the performance issue was slower response time of Cassandra 3.10 get_slice as 
> compared to Cassandra 1.2.18 (almost x3 times slower on average).
> I am attaching a python script (attack.py) here that can be used to reproduce 
> this issue on a Windows platform. The script uses the pycassa python library 
> that can easily be installed using pip.
> REPRODUCTION STEPS:
> 1. Install Cassandra 1.2.18 from 
> https://archive.apache.org/dist/cassandra/1.2.18/apache-cassandra-1.2.18-bin.tar.gz
> 2. Run Cassandra 1.2.18 from cmd console using cassandra.bat
> 3. Create a test keyspace and an empty CF using attack.py script
>    
> {noformat}
> python attack.py create
> {noformat}
> 4. Run some get_slice queries to an empty CF and note down the average 
> response time (in seconds)
>    
> {noformat}
> python attack.py
> {noformat}
>    get_slice count: 788
>    get_slice total response time: 0.31299996376
>    *get_slice average response time: 0.000397208075838*
> 5. Stop Cassandra 1.2.18 and install Cassandra 3.10 from 
> https://archive.apache.org/dist/cassandra/3.10/apache-cassandra-3.10-bin.tar.gz
> 6. Tweak cassandra.yaml to run thrift service (start_rpc=true) and run 
> Cassandra from an elevated cmd console using cassandra.bat
> 7. Create a test keyspace and an empty CF using attack.py script
>    
> {noformat}
> python attack.py create
> {noformat}
> 8. Run some get_slice queries to an empty CF using attack.py and note down 
> the average response time (in seconds)
> {noformat}
> python attack.py
> {noformat}
>    get_slice count: 788
>    get_slice total response time: 1.16499996185
>    *get_slice average response time: 0.00147842634753*
> 9. Compare the average response times
> EXPECTED:
>    get_slice response time of Cassandra 3.10 is not worse than on Cassandra 
> 1.2.18
> ACTUAL:
>    get_slice response time of Cassandra 3.10 is x3 worse than that of 
> Cassandra 1.2.18
> REMARKS:
> - this seems to happen only on Windows platform (tested on Windows 10 and 
> Windows Server 2008 R2)
> - running the very same procedure on Linux (Ubuntu) renders roughly the same 
> response times
> - I sniffed the traffic to/from Cassandra 1.2.18 and Cassandra 3.10 and it 
> can be seen that Cassandra 3.10 responds slower (Wireshark dumps attached)
> - when attacking the server with concurrent get_slice queries I can see lower 
> CPU usage for Cassandra 3.10 that for Cassandra 1.2.18
> - get_slice in attack.py queries the column family for non-exisitng key (the 
> column familiy is empty)
> I am willing to work on this on my own if you guys give me some tips on where 
> to look for. I am also aware that this might be more Windows/Java related, 
> nevertheless, any help from your side would be much appreciated.



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