On Friday, July 13, 2012 5:14:53 PM, "John Vines" <[email protected]> wrote: > Sounds like you want to use the TableLoadBalancer which will try to > even balance all tablets on a table-by-table basis.
To use this, set "master.tablet.balancer" to "org.apache.accumulo.server.master.balancer.TableLoadBalancer". This has been made the default balancer as of 1.4.1. Billie > John > > > On Fri, Jul 13, 2012 at 5:09 PM, ameet kini < [email protected] > > wrote: > > > Thanks, I was looking for something of the equivalent: > http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HBaseAdmin.html#move(byte[], > byte[]) > > > The use case is common enough that there may be some other way to do > what I want. I have a table that doesn't have its tablets distributed > evenly. At the system (instance?) level, they are evenly distributed, > but not at this particular table level. > > > The docs seem to suggest that pre-splitting a table would > automatically guarantee that the tablets would be distributed evenly > across the nodes of the cluster. I see that pre-splitting guarantees > that you have that many tablets, but not necessarily that they are > evenly distributed. Maybe if the instance had only one table, then it > would be forced to distribute its tablets. > > > > Thanks, > Ameet > > > PRE-SPLITTING TABLES > > > Accumulo will balance and distribute tables accross servers. Before a > table gets large, it will be maintained as a single tablet on a single > server. This limits the speed at which data can be added or queried to > the speed of a single node. To improve performance when the a table is > new, or small, you can add split points and generate new tablets. > > In the shell: > root @myinstance > createtable newTable root @myinstance > addsplits - > t newTable g n t > > This will create a new table with 4 tablets. The table will be split > on the letters g'', n'', and ``t'' which will work nicely if the row > data start with lower-case alphabetic characters. If your row data > includes binary information or numeric information, or if the > distribution of the row information is not flat, then you would pick > different split points. Now ingest and query can proceed on 4 nodes > which can improve performance. > > > > > > > > > > > > > > On Fri, Jul 13, 2012 at 3:04 PM, Eric Newton < [email protected] > > wrote: > > > Yes, you need to write your own tablet balancer. > > -Eric > > > > On Fri, Jul 13, 2012 at 2:48 PM, ameet kini < [email protected] > > wrote: > > > > Hi, > > > > Is there a way to force a tablet to move to a particular tablet > > server? > > > > Thanks, > > Ameet
