Re: JMX CF Beans
thanks. both of you. Nicolas Le 25 janv. 2013 à 19:05, Tyler Hobbs ty...@datastax.com a écrit : On Fri, Jan 25, 2013 at 8:07 AM, Nicolas Lalevée nicolas.lale...@hibnet.org wrote: Just a quick question about the attributes exposed via JMX. I have some doc [1] but it doesn't help about CF beans. The BloomFilterFalseRatio, is that the ratio of found vs missed, or the ratio of false positive vs the number of tests, or something else ? False positives. You should be aware of this bug, though: https://issues.apache.org/jira/browse/CASSANDRA-4043 The ReadCount and WriteCount, how do they count regarding the replication factor ? As far as I understand, the read and write on the StorageProxy is the actual number of requests coming from clients. So judging that the sum on all cf of the read and write is near equal to the replication factor multiply by the number of read and write on the StorageProxy, I am guessing that the read and write per cf are the replicas one. Am I right ? StorageProxy read/write counts should equal the number of client requests. ColumnFamily read/write counts correspond to actual, local data reads, so the sum of this number across all nodes will be approximately RF * the StorageProxy counts. -- Tyler Hobbs DataStax
RE: JMX CF Beans
src/java/org/apache/цassandra/db/DataTracker.java:
public double getBloomFilterFalseRatio()
{
…
return (double) falseCount / (trueCount + falseCount);
…
}
ReadCount/WriteCount on CF is for this CF on this node only, so it’s
local/internal only reads/writes for the node’s range.
Best regards / Pagarbiai
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From: Nicolas Lalevée [mailto:nicolas.lale...@hibnet.org]
Sent: Friday, January 25, 2013 16:08
To: user@cassandra.apache.org
Subject: JMX CF Beans
Just a quick question about the attributes exposed via JMX. I have some doc [1]
but it doesn't help about CF beans.
The BloomFilterFalseRatio, is that the ratio of found vs missed, or the ratio
of false positive vs the number of tests, or something else ?
The ReadCount and WriteCount, how do they count regarding the replication
factor ? As far as I understand, the read and write on the StorageProxy is the
actual number of requests coming from clients. So judging that the sum on all
cf of the read and write is near equal to the replication factor multiply by
the number of read and write on the StorageProxy, I am guessing that the read
and write per cf are the replicas one. Am I right ?
Nicolas
[1] http://wiki.apache.org/cassandra/JmxInterface
inline: signature-logo914.pnginline: signature-best-employer-logo3b0d.png
Re: JMX CF Beans
On Fri, Jan 25, 2013 at 8:07 AM, Nicolas Lalevée nicolas.lale...@hibnet.org wrote: Just a quick question about the attributes exposed via JMX. I have some doc [1] but it doesn't help about CF beans. The BloomFilterFalseRatio, is that the ratio of found vs missed, or the ratio of false positive vs the number of tests, or something else ? False positives. You should be aware of this bug, though: https://issues.apache.org/jira/browse/CASSANDRA-4043 The ReadCount and WriteCount, how do they count regarding the replication factor ? As far as I understand, the read and write on the StorageProxy is the actual number of requests coming from clients. So judging that the sum on all cf of the read and write is near equal to the replication factor multiply by the number of read and write on the StorageProxy, I am guessing that the read and write per cf are the replicas one. Am I right ? StorageProxy read/write counts should equal the number of client requests. ColumnFamily read/write counts correspond to actual, local data reads, so the sum of this number across all nodes will be approximately RF * the StorageProxy counts. -- Tyler Hobbs DataStax http://datastax.com/
