Options

ReflexiveMoveout configuration parameter

Hello, 

 

I would like to know what is the usage of this ReflexiveMoveout parameter? We have 12 nodes  version 7.2.3-10 vertica   and one of the nodes's WOS keeps getting full (16GB) and starts doing WOS_SPILL which looks like it impacts whole cluster's performance. Even though i decreased both MoveOutInterval (200) and MoveOutMaxAgeTime(900) , we're still seeing one node doing too many WOS_SPILL . For permenant solution we may need to check segmentation of projections but for short term solution , I'm trying to optimize mouveou and mergeout intervals . I was looking for detailed ReflexiveMoveout  explanation but could not find on documentation.Could you please give examples of use case of this parameter please ?

 

Thanks

 

 

Comments

  • Options
    SruthiASruthiA Vertica Employee Administrator

    Are you doing trickle loading? Do you use DIRECT keyword when loading data? 

  • Options

    Hello ,

     

    We're using both trickle and direct loading , we found our problem is TM moveout is delayed because  some open sessions(SELECT 1) coming from our report servers  holding Global Catalog X lock . I would still like to learn use cases of enabling ReflexiveMoveout parameter, I could not find any explanation for how does that parameter work.

  • Options

    ReflexiveMoveout works with MoveOutSizePct, and what it does is when you commit vertica sees if the wos meets the MoveOutSizePct, if it so, it force a moveout.

    If the ReflexiveMoveout is off data is moved from the WOS when the TM runs on committed data.

    Hope this helps.
    Eugenia

  • Options

    I also recomend you check following knowledge base document on tuple mover. It does not talk about reflexiveMoveout but has useful information to solve your problem.

    https://community.dev.hpe.com/t5/Vertica-Knowledge-Base/Tuple-Mover-Best-Practices/ta-p/235261

Leave a Comment

BoldItalicStrikethroughOrdered listUnordered list
Emoji
Image
Align leftAlign centerAlign rightToggle HTML viewToggle full pageToggle lights
Drop image/file