Pick a PUT coordinator based on vnode mailbox queue length#1670
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russelldb wants to merge 19 commits into
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Pick a PUT coordinator based on vnode mailbox queue length#1670russelldb wants to merge 19 commits into
russelldb wants to merge 19 commits into
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Trying to track down the deluge of timeout messages at pb server
Rather than forward from a non-local to a local, and then maybe forward again for soft-limit, if the put lands on a non-preflist node, check the remote mailboxes and pick the first to answer with a non-loaded mailbox. Fixes the bug where a non-preflist forwarding put fsm would never receive an ack, and therefore would run prepare/put and finally send an ignored message to riak_api_pn_server, resulting in log spam
IN the case that ALL preflist entries are "loaded" we select the least loaded. The function returned an Entry, not a node(). This commit fixes that. NOTE: shoulda used dialyzer!
This reverts commit 8b2cd88.
The sort now returns a node, not an entry, fix the test to match
russelldb
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See riak#1661 for initial discussion
This PR depends on basho/riak_core#921
Even a small vnode queue can lead to large fluctuations in higher-percentile latencies for coordinated PUT operations.
This PR uses the vnode proxy's estimate of the vnode queue length to select a PUT coordinator.
BEFORE:
AFTER:
soft-limitthe node coordinates the put.soft-limitor the proxy does not respond in time, check the remote preflist nodes's vnode queues.soft-limitis forwarded to.We tested this for 24hrs on the NHS benchmark cluster, using leveldb, and saw a significant improvement in 99th+ percentile latencies. See