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) InputStream.read(), 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 <[email protected]> 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 <[email protected]> >>> wrote: >>>> 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. >> >>
