Re: Can't select count(*)

[Stefania Alborghetti]

Regarding select count(*), the timeout is probably client side. Try
changing the default connect timeout in cqlsh via --request-timeout. By
default it is 10 seconds. Refer to "cqlsh --help" for more details but
basically "cqlsh --request-timeout=30" should work.

Regarding COPY TO/FROM, these commands were recently enhanced and should be
available in 2.2.5 (not yet released). More details in this blog post:
http://www.datastax.com/dev/blog/new-features-in-cqlsh-copy. The problem
with COPY FROM prior to this enhancement is that it only contacts one
replica, so it is subject to coordinator timeouts regardless of the size of
the cluster, and it does not retry on timeouts. It just aborts.

Release 2.2.5 should be available soon but if you cannot wait till then you
can try downloading the source code for 2.2 HEAD and running cqlsh from
there. It should be compatible.

EC2 t2.small is probably too weak but I don't know enough about AWS
instances to comment further about this.

On Mon, Feb 1, 2016 at 3:56 PM, Ivan Zelensky  wrote:

> Hi all! I have a table with simple primary key (one field on primary key
> only), and ~1 million records. Table stored on single-node C* 2.2.4.
> Problem: when I'm trying to execute "SELECT count(*) FROM my_table;",
> operation is timed out.
> As I understand, 1 mln rows is not so big dataset to use MapRed to count
> it, so I thing it is smth wrong with configuration.
> Also I can't do "COPY TO/FROM" when dataset > 30 000 rows.
> Also maybe it is too weak hadrware (AWS EC2 t2.small), but even on
> t2.large I had timeout on COPY, just on 300 000 rows.
>
> My configuration is default config from deb package. Maybe somebody know
> what I should to tweak there?
>
> Thank you.
>



-- 


[image: datastax_logo.png] 

Stefania Alborghetti

Apache Cassandra Software Engineer

|+852 6114 9265| stefania.alborghe...@datastax.com

Can't select count(*)

[Ivan Zelensky]

Hi all! I have a table with simple primary key (one field on primary key
only), and ~1 million records. Table stored on single-node C* 2.2.4.
Problem: when I'm trying to execute "SELECT count(*) FROM my_table;",
operation is timed out.
As I understand, 1 mln rows is not so big dataset to use MapRed to count
it, so I thing it is smth wrong with configuration.
Also I can't do "COPY TO/FROM" when dataset > 30 000 rows.
Also maybe it is too weak hadrware (AWS EC2 t2.small), but even on t2.large
I had timeout on COPY, just on 300 000 rows.

My configuration is default config from deb package. Maybe somebody know
what I should to tweak there?

Thank you.