On Mon, Jul 4, 2016 at 2:46 AM, 袁康(梓悠) <yuankang.yk@alibaba-inc.com> wrote:
How can I delete data in kudu table wiht spark  (not delete the table at all)?

We do not currently have a way to delete a Kudu table through the spark connector, but you should be able to instantiate a Kudu client and delete the table that way.  We have discussed making one of the spark write modes do a truncate operation, but nothing has been implemented.

 - Dan
 
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发件人:Todd Lipcon <todd@cloudera.com>
发送时间:2016年7月2日(星期六) 02:44
主 题:Re: Performance Question

On Thu, Jun 30, 2016 at 5:39 PM, Benjamin Kim <bbuild11@gmail.com> wrote:
Hi Todd,

I changed the key to be what you suggested, and I can’t tell the difference since it was already fast. But, I did get more numbers.

Yea, you won't see a substantial difference until you're inserting billions of rows, etc, and the keys and/or bloom filters no longer fit in cache.
 

> 104M rows in Kudu table
- read: 8s
- count: 16s
- aggregate: 9s

The time to read took much longer from 0.2s to 8s, counts were the same 16s, and aggregate queries look longer from 6s to 9s.

I’m still impressed.

We aim to please ;-) If you have any interest in writing up these experiments as a blog post, would be cool to post them for others to learn from.

-Todd
 
On Jun 15, 2016, at 12:47 AM, Todd Lipcon <todd@cloudera.com> wrote:

Hi Benjamin,

What workload are you using for benchmarks? Using spark or something more custom? rdd or data frame or SQL, etc? Maybe you can share the schema and some queries

Todd

Todd

On Jun 15, 2016 8:10 AM, "Benjamin Kim" <bbuild11@gmail.com> wrote:
Hi Todd,

Now that Kudu 0.9.0 is out. I have done some tests. Already, I am impressed. Compared to HBase, read and write performance are better. Write performance has the greatest improvement (> 4x), while read is > 1.5x. Albeit, these are only preliminary tests. Do you know of a way to really do some conclusive tests? I want to see if I can match your results on my 50 node cluster.

Thanks,
Ben

On May 30, 2016, at 10:33 AM, Todd Lipcon <todd@cloudera.com> wrote:

On Sat, May 28, 2016 at 7:12 AM, Benjamin Kim <bbuild11@gmail.com> wrote:
Todd,

It sounds like Kudu can possibly top or match those numbers put out by Aerospike. Do you have any performance statistics published or any instructions as to measure them myself as good way to test? In addition, this will be a test using Spark, so should I wait for Kudu version 0.9.0 where support will be built in?

We don't have a lot of benchmarks published yet, especially on the write side. I've found that thorough cross-system benchmarks are very difficult to do fairly and accurately, and often times users end up misguided if they pay too much attention to them :) So, given a finite number of developers working on Kudu, I think we've tended to spend more time on the project itself and less time focusing on "competition". I'm sure there are use cases where Kudu will beat out Aerospike, and probably use cases where Aerospike will beat Kudu as well.

From my perspective, it would be great if you can share some details of your workload, especially if there are some areas you're finding Kudu lacking. Maybe we can spot some easy code changes we could make to improve performance, or suggest a tuning variable you could change.

-Todd


On May 27, 2016, at 9:19 PM, Todd Lipcon <todd@cloudera.com> wrote:

On Fri, May 27, 2016 at 8:20 PM, Benjamin Kim <bbuild11@gmail.com> wrote:
Hi Mike,

First of all, thanks for the link. It looks like an interesting read. I checked that Aerospike is currently at version 3.8.2.3, and in the article, they are evaluating version 3.5.4. The main thing that impressed me was their claim that they can beat Cassandra and HBase by 8x for writing and 25x for reading. Their big claim to fame is that Aerospike can write 1M records per second with only 50 nodes. I wanted to see if this is real.

1M records per second on 50 nodes is pretty doable by Kudu as well, depending on the size of your records and the insertion order. I've been playing with a ~70 node cluster recently and seen 1M+ writes/second sustained, and bursting above 4M. These are 1KB rows with 11 columns, and with pretty old HDD-only nodes. I think newer flash-based nodes could do better.
 

To answer your questions, we have a DMP with user profiles with many attributes. We create segmentation information off of these attributes to classify them. Then, we can target advertising appropriately for our sales department. Much of the data processing is for applying models on all or if not most of every profile’s attributes to find similarities (nearest neighbor/clustering) over a large number of rows when batch processing or a small subset of rows for quick online scoring. So, our use case is a typical advanced analytics scenario. We have tried HBase, but it doesn’t work well for these types of analytics.

I read, that Aerospike in the release notes, they did do many improvements for batch and scan operations.

I wonder what your thoughts are for using Kudu for this.

Sounds like a good Kudu use case to me. I've heard great things about Aerospike for the low latency random access portion, but I've also heard that it's _very_ expensive, and not particularly suited to the columnar scan workload. Lastly, I think the Apache license of Kudu is much more appealing than the AGPL3 used by Aerospike. But, that's not really a direct answer to the performance question :)
 

Thanks,
Ben


On May 27, 2016, at 6:21 PM, Mike Percy <mpercy@cloudera.com> wrote:

Have you considered whether you have a scan heavy or a random access heavy workload? Have you considered whether you always access / update a whole row vs only a partial row? Kudu is a column store so has some awesome performance characteristics when you are doing a lot of scanning of just a couple of columns.

I don't know the answer to your question but if your concern is performance then I would be interested in seeing comparisons from a perf perspective on certain workloads.

Finally, a year ago Aerospike did quite poorly in a Jepsen test: https://aphyr.com/posts/324-jepsen-aerospike

I wonder if they have addressed any of those issues.

Mike

On Friday, May 27, 2016, Benjamin Kim <bbuild11@gmail.com> wrote:
I am just curious. How will Kudu compare with Aerospike (http://www.aerospike.com)? I went to a Spark Roadshow and found out about this piece of software. It appears to fit our use case perfectly since we are an ad-tech company trying to leverage our user profiles data. Plus, it already has a Spark connector and has a SQL-like client. The tables can be accessed using Spark SQL DataFrames and, also, made into SQL tables for direct use with Spark SQL ODBC/JDBC Thriftserver. I see from the work done here http://gerrit.cloudera.org:8080/#/c/2992/ that the Spark integration is well underway and, from the looks of it lately, almost complete. I would prefer to use Kudu since we are already a Cloudera shop, and Kudu is easy to deploy and configure using Cloudera Manager. I also hope that some of Aerospike’s speed optimization techniques can make it into Kudu in the future, if they have not been already thought of or included.

Just some thoughts…

Cheers,
Ben


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Mike Percy
Software Engineer, Cloudera






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Todd Lipcon
Software Engineer, Cloudera




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Todd Lipcon
Software Engineer, Cloudera





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Todd Lipcon
Software Engineer, Cloudera