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From: "Hiller, Dean" <Dean.Hiller@nrel.gov>
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
Date: Fri, 8 Mar 2013 12:26:54 -0700
Subject: has anyone used dynamic snitch at all
Thread-Topic: has anyone used dynamic snitch at all
Thread-Index: Ac4cMuCLJ1Yyt/s/SyWGRmnfyPe/OQ==
Message-ID: <CD5F898E.22BC7%Dean.Hiller@nrel.gov>
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Our test setup

4 nodes, RF=3D3, reads at CL=3DQUOROM and we tried CL=3DTWO
Tell the network card to slow down every packet on node 2
After fixing astyanax to not go to node 2 anymore, we are still seeing cass=
andra have issues as it seems to be involving node 2 somehow.  If we take n=
ode 2 down, it all speeds back up.

We are trying to get this working such that a slow node in cassandra does n=
ot impact our customers.

We are in 1.2.2 and added the following properties=85.(our properties show =
PropertyFileSnitch though I see the keyspace has org.apache.cassandra.locat=
or.SimpleStrategy set probably because it was created through a tool instea=
d of CLI=85shucks)=85.anyways, I still expected dynamic snitch to work=85.

# controls how often to perform the more expensive part of host score
# calculation
dynamic_snitch: true
dynamic_snitch_update_interval_in_ms: 100
# controls how often to reset all host scores, allowing a bad host to
# possibly recover
dynamic_snitch_reset_interval_in_ms: 600000
# if set greater than zero and read_repair_chance is < 1.0, this will allow
# 'pinning' of replicas to hosts in order to increase cache capacity.
# The badness threshold will control how much worse the pinned host has to =
be
# before the dynamic snitch will prefer other replicas over it.  This is
# expressed as a double which represents a percentage.  Thus, a value of
# 0.2 means Cassandra would continue to prefer the static snitch values
# until the pinned host was 20% worse than the fastest.
dynamic_snitch_badness_threshold: 0.1

Any help appreciated,
Thanks,
Dean