>>Watching trends on these pools for increases in the pending tasks >>column is an excellent indicator of the need to add additional capacity.

Additional capacity meaning add more writers and reader threads to handle the requests  ?


On Tue, Oct 1, 2013 at 12:22 PM, Robert Coli <rcoli@eventbrite.com> wrote:
On Wed, Aug 28, 2013 at 5:47 AM, Girish Kumar <girishkumarbk@gmail.com> wrote:
When high number of Pending tasks are showing up what it means to cassandra? What are the reasons for high number pending tasks?  Does that mean Cassandra is overloaded ? 

It means that tasks have been queued to run inside of a Thread Pool, but are not currently running. A given task moves from Pending to Active state, and then Completed. "Blocked" is "I attempted to move something from Pending to Active, but was unable to."

"
Cassandra maintains distinct thread pools for different stages of execution. Each of these thread pools provide statistics on the number of tasks that are active, pending and completed. Watching trends on these pools for increases in the pending tasks column is an excellent indicator of the need to add additional capacity.
"

=Rob