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From Josh Elser <>
Subject Re: why not check TTL interval
Date Sat, 06 Jun 2015 05:37:30 GMT
The decrease in performance you see is probably because the iterator 
must read a significant amount of old data. If you don't write new data 
to a table, Accumulo will not run any compactions and no data will 
age-off in the files on HDFS.

I think it would be fairly common to use crontab to regularly schedule 
compactions over your table so that data is automatically deleted (e.g. 
nightly). Accumulo doesn't contain any means to automate this internally.

Lu Qin wrote:
> I have a big table about 38B entries, and I set a ageoff iterator with a ttl about 3
days,I set the iteratorPriority is 10 and apply it in all-scopes.
> I stop write data into it about one week,and now I scan it ,but it wait so long. I check
the monitor page,it show me that the scan speed is 80w entries/s.
> I think the ageoff is a diferent iterator than others,if all data is out the ttl,when
I scan the table,it will scan all data in the table and decide to remove it,right? Why not
do this interval ?
> Thanks

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