Will Berkeley created KUDU-2316:
-----------------------------------

             Summary: Expose more information about a tablet's rowsets
                 Key: KUDU-2316
                 URL: https://issues.apache.org/jira/browse/KUDU-2316
             Project: Kudu
          Issue Type: Improvement
    Affects Versions: 1.6.0
            Reporter: Will Berkeley
         Attachments: rowsetblackbarofdeath.png

Right now it's kind of hard to get an idea what a tablet's DRSs look like. We 
expose some information in a few ways:
 * the /tablet-rowsetlayout-svg page in the web ui
 * kudu local_replica dump meta
 * kudu fs list

but, for example, if I wanted to find out how many DRS a tablet has, I'd have 
to pipe the output from one of the tools through a grep and wc -l or something. 
If I wanted to find out the average size of a rowset I could take that number 
and divide it into the tablet's size on disk to get an upper bound. If I wanted 
a measurement of how uncompacted a tablet's rowsets are I can look at the 
picture on the web ui.

We should have some better metrics:
 # Count of DRS for a tablet
 # An average DRS size (better, a histogram)
 # Some number measuring how much rowsets overlap in primary key space

These should be exposed as metrics and on the webui. When possible, they should 
also be exposed by tools- 1 ought to be available, whereas 2 and 3 might not be 
worth computing as part of a tool.



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

Reply via email to