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https://issues.apache.org/jira/browse/CASSANDRA-11053?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jeremiah Jordan reopened CASSANDRA-11053:
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On the following node:
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Linux atest-55c62b1 3.13.0-74-generic #118-Ubuntu SMP Thu Dec 17 22:52:10 UTC
2015 x86_64 x86_64 x86_64 GNU/Linux
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Running cassandra-3.0 HEAD this copy change is broken for a simple test.
{code}
$ cat kv.cql
create keyspace if not exists cvs_copy_ks with replication = {'class':
'SimpleStrategy', 'replication_factor':1};
create table if not exists cvs_copy_ks.kv (key int primary key, value text);
truncate cvs_copy_ks.kv;
copy cvs_copy_ks.kv (key, value) from 'kv.csv' with header='true';
select * from cvs_copy_ks.kv;
{code}
{code}
$ cat kv.csv
key,value
1,'a'
2,'b'
3,'c'
{code}
If I run that it just hangs.
{code}
./cqlsh -f kv.cql
Using 1 child processes
Starting copy of cvs_copy_ks.kv with columns ['key', 'value'].
{code}
I added some debug and it hangs in spinning here
https://github.com/apache/cassandra/blob/cassandra-3.0/pylib/cqlshlib/copyutil.py#L1166
Because channels is an empty list.
> COPY FROM on large datasets: fix progress report and debug performance
> ----------------------------------------------------------------------
>
> Key: CASSANDRA-11053
> URL: https://issues.apache.org/jira/browse/CASSANDRA-11053
> Project: Cassandra
> Issue Type: Bug
> Components: Tools
> Reporter: Stefania
> Assignee: Stefania
> Labels: doc-impacting
> Fix For: 2.1.14, 2.2.6, 3.0.5, 3.5
>
> Attachments: copy_from_large_benchmark.txt,
> copy_from_large_benchmark_2.txt, parent_profile.txt, parent_profile_2.txt,
> worker_profiles.txt, worker_profiles_2.txt
>
>
> h5. Description
> Running COPY from on a large dataset (20G divided in 20M records) revealed
> two issues:
> * The progress report is incorrect, it is very slow until almost the end of
> the test at which point it catches up extremely quickly.
> * The performance in rows per second is similar to running smaller tests with
> a smaller cluster locally (approx 35,000 rows per second). As a comparison,
> cassandra-stress manages 50,000 rows per second under the same set-up,
> therefore resulting 1.5 times faster.
> See attached file _copy_from_large_benchmark.txt_ for the benchmark details.
> h5. Doc-impacting changes to COPY FROM options
> * A new option was added: PREPAREDSTATEMENTS - it indicates if prepared
> statements should be used; it defaults to true.
> * The default value of CHUNKSIZE changed from 1000 to 5000.
> * The default value of MINBATCHSIZE changed from 2 to 10.
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