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From: Paul Ingalls <paulingalls@gmail.com>
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Subject: understanding memory footprint
Message-Id: <BF752BD8-0630-4D90-BD99-E3A009FD9B2B@gmail.com>
Date: Mon, 12 Aug 2013 10:22:36 -0700
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
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I'm trying to get a handle on how newer cassandra handles memory.  Most =
of what I am seeing via google, on the wiki etc. appears old.  For =
example, this wiki article appears out of date relative to post 1.0:

http://wiki.apache.org/cassandra/MemtableThresholds

specifically this is the section I'm looking at:

 For a rough rule of thumb, Cassandra's internal datastructures will =
require about memtable_throughput_in_mb * 3 * number of hot CFs + 1G + =
internal caches.

is this still true?  I thought memtable_throughput_in_mb is deprecated.  =
Is there any equivalent calculation/rule of thumb for cassandra post =
1.0?

At the core, my question really is:

"Does the number of column families still significantly impact the =
memory footprint? If so, what is the incremental cost of a column =
family/table?"

and the available docs aren't helping me answer it=85

Thanks!

Paul=

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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html =
charset=3Dwindows-1252"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I'm =
trying to get a handle on how newer cassandra handles memory. &nbsp;Most =
of what I am seeing via google, on the wiki etc. appears old. &nbsp;For =
example, this wiki article appears out of date relative to post =
1.0:<div><br></div><div><a =
href=3D"http://wiki.apache.org/cassandra/MemtableThresholds">http://wiki.a=
pache.org/cassandra/MemtableThresholds</a></div><div><br></div><div>specif=
ically this is the section I'm looking =
at:</div><div><br></div><div>&nbsp;For a rough rule of thumb, =
Cassandra's internal datastructures will require =
about&nbsp;memtable_throughput_in_mb * 3 * number of hot CFs + 1G + =
internal caches.<br>
<br></div><div>is this still true? &nbsp;I thought =
memtable_throughput_in_mb is deprecated. &nbsp;Is there any equivalent =
calculation/rule of thumb for cassandra post =
1.0?</div><div><br></div><div>At the core, my question really =
is:</div><div><br></div><div>"Does the number of column families still =
significantly impact the memory footprint? If so, what is the =
incremental cost of a column family/table?"</div><div><br></div><div>and =
the available docs aren't helping me answer =
it=85</div><div><br></div><div>Thanks!</div><div><br></div><div>Paul</div>=
</body></html>=

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