Make vnode check for existing handoff before starting another #250
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Change riak_core_vnode to keep track of the handoff sender pid and not initiate a new handoff if an existing handoff is already running. In practice, this is not necessary as the handoff manager ensures that only one handoff is running per source/target pair. This change is an optimization to avoid additional work that is potentially expensive on some backends.
ghost
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jaredmorrow
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Nov 6, 2012
Make vnode check for existing handoff before starting another
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Change riak_core_vnode to keep track of the handoff sender pid and not initiate a new handoff if an existing handoff is already running. In practice, this is not necessary as the handoff manager ensures that only one handoff is running per source/target pair. This change is an optimization to avoid additional work that is potentially expensive on some backends.
Note: This is tangentially related to basho/riak_kv#423 as one of the blocking scenarios was "double handoff". The second handoff attempt would call
bitcask:is_emptyand therefore trigger the reported blocking behavior. That issue is resolved by the Bitcask changes associated with the issue, but changing handoff behavior to not unnecessarily attempt to handoff is a reasonable optimization to do regardless.