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https://issues.apache.org/jira/browse/CASSANDRA-6179?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jonathan Ellis updated CASSANDRA-6179:
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Assignee: Mikhail Stepura
> "Load" calculated in "nodetool info" is strange/inaccurate in JBOD setups
> -------------------------------------------------------------------------
>
> Key: CASSANDRA-6179
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6179
> Project: Cassandra
> Issue Type: Bug
> Environment: JBOD layouts
> Reporter: J. Ryan Earl
> Assignee: Mikhail Stepura
>
> We recently noticed that the storage capacity on Cassandra nodes using JBOD
> layout was returning what looks close to the average data volume size,
> instead of the sum of all JBOD data volumes. It's not exactly an average and
> I haven't had time to dig into the code to see what it's really doing, it's
> like some sort of sample of the JBOD volumes sizes.
> So looking at the JBOD volumes we see:
> {noformat}
> [jre@cassandra2 ~]$ df -h
> Filesystem Size Used Avail Use% Mounted on
> [...]
> /dev/sdc1 1.1T 9.4G 1.1T 1% /data/1
> /dev/sdd1 1.1T 9.2G 1.1T 1% /data/2
> /dev/sde1 1.1T 11G 1.1T 1% /data/3
> /dev/sdf1 1.1T 11G 1.1T 1% /data/4
> /dev/sdg1 1.1T 9.2G 1.1T 1% /data/5
> /dev/sdh1 1.1T 11G 1.1T 1% /data/6
> /dev/sdi1 1.1T 9.8G 1.1T 1% /data/7
> {noformat}
> Looking at 'nodetool info' we see:
> {noformat}
> [jre@cassandra2 ~]$ nodetool info
> Token : (invoke with -T/--tokens to see all 256 tokens)
> ID : 631f0be3-ce52-4eb9-b48b-069fbfdf0a97
> Gossip active : true
> Thrift active : true
> Native Transport active: true
> Load : 10.57 GB
> {noformat}
> So there are 7 disks in a JBOD configuration in this example, the sum should
> be closer to 70G for each node. Maybe we're misinterpreting what this value
> should be, but things like OpsCenter appear to use this "load" value as the
> size of data on the local node, which I expect to be the sum of JBOD volumes.
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