Module riak_pipe_qcover_fsm

The qcover fsm manages enqueueing the same work on a set of vnodes that covers the space of data with a replication factor of N.

Behaviours: riak_core_coverage_fsm.

Description

The qcover fsm manages enqueueing the same work on a set of vnodes that covers the space of data with a replication factor of N. This can be used, for example, to ask 1/Xth of the cluster to list keys for data stored in Riak KV with N=X.

When using qcover to send Input, workers for the fitting will receive input of the form {cover, FilterVNodes, Input}.

IMPORTANT: Fittings that will receive their inputs via this qcover fsm should be started with their nval=1. Pipe nval failover should not be used with qcover inputs, because the vnode filter is meant only for the vnode that initially receives the request.

Note also that the chashfun fitting parameter has no effect when using qcover. Coverage is computed purely via the qcover's NVal.

Function Index

finish/2
init/2
process_results/2

Function Details

finish/2

finish(X1, State) -> any()

init/2

init(From, X2) -> any()

process_results/2

process_results(X1, State) -> any()


Generated by EDoc, Nov 29 2012, 06:39:40.