ReflexiveMoveout configuration parameter

caliskurahmet

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

 

 

SruthiA

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

caliskurahmet

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.

emoreno

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

[Deleted User]

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