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From Timo Nentwig <>
Subject Re: Very simple benchmark - are this typical numbers?
Date Tue, 08 Dec 2009 16:16:04 GMT
On Dec 7, 2009, at 7:23 PM, Jonathan Ellis wrote:

> same thing, you are going to need multiple threads to max it out

I created up to 100 threads and read randomly. Some speed up but not actually mentionable.
The threads didn't load the CPU mentionably either. I noticed that the thread dump was full
of Thift (TBinaryProtocol something), 10MiB constant read from HD.

> but yes, reads are typically slower than writes in cassandra because
> of how the log-based merge structures work
> On Mon, Dec 7, 2009 at 11:09 AM, Timo Nentwig <> wrote:
>> On Dec 7, 2009, at 5:59 PM, Jonathan Ellis wrote:
>>> yes and no -- that's about 4200/s, which is typical for only a single
>> When writing, yes. But I would expect reading to be much faster (?). Re-executing
the read test doesn't speed up things either (I/O caches).
>>> thread but 1/3 to 1/5 of what you'd expect it to max out (on our
>>> quad-core test boxes) when you add client threads
>>> On Mon, Dec 7, 2009 at 10:38 AM, Timo Nentwig <>
>>>> Hi!
>>>> I just downloaded, installed, start cassandra and ran very simple "benchmark":
write n times something with key==value==testInsertAndGetAndRemove_n (one thread).
>>>> For n==10 million on a 7200rpm HDD (4G RAM - there should have be "reasonably"
free mem however I didn't check) this took 40min (insert()ing one after another). Reading
them one by one in sequence delivers about 100/s, reading in 1.000er batches (i.e. multigetColumn())
takes 5-10s (depending on n, the higher the slower).
>>>> Are this typical numbers for cassandra (0.5)? I actually took the configuration
as it was.

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