Probably worth adding that the table mentioned below has a bunch of tablets on other tablet servers as well, which is why I'm using BatchScanner. I'm just not sure how the numQueryThreads relates to the number of a concurrent scans on a given tablet server.
Thanks On Tue, Sep 25, 2012 at 2:22 PM, ameet kini <[email protected]> wrote: > > I have a table with 4 tablets on a given tablet server. Depending on the > numQueryThreads parameter below, I see a varying number of maximum > concurrent scans on that table. This maximum number varies from 1 to 3 > (i.e., some values for numQueryThreads result in maximum concurrent scan of > 1, some values result in 2 concurrent scans, etc.). Can someone shed light > on what is the relationship between numQueryThreads and number of > concurrent scans? > > public BatchScanner createBatchScanner(String tableName, > Authorizations authorizations, > int numQueryThreads) > > A follow-on question would be what is general rule of thumb for setting > numQueryThreads? Should it be set to the # of hosted tablets expected to > be consumed by that BatchScanner? Should it be the # of tablet servers > expected to be hit by that BatchScanner? Something else? > > Thanks, > Ameet > > >
