bulk loadingdataintocassandra 140307160517 phpapp02

5/21/2018 Bulk Loadingdataintocassandra 140307160517 Phpapp02

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Bulk-Loading Data into Cassandra

Patricia Gorla

@patriciagorla

Cassandra Consultant

www.thelastpickle.com

Planet Cassandra 2014
http://www.thelastpickle.com/


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About Us

" Work with clients to deliver and improve

Apache Cassandra services

" Apache Cassandra committer, Datastax

MVP, Hector maintainer, Apache Usergrid

committer

" Based in New Zealand & USA


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Why is bulk loading useful?

" Performance tests


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" Performance tests

" Migrating historical data


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" Performance tests

" Migrating historical data

" Changing topologies


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" How Data is Stored

" Case Studies

- Generating Dummy Data

- Backfilling Historical Data

-Changing Topologies

" Conclusion


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Cassandra Write Path write[


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Cassandra Write Path

" Writes written to both the commit log and

memtable.

write[

memtabcommitlog


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" Writes written to both the commit log and

memtable.

" Memtable is sorted.

write[

memtabcommitlog


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" Memtable flushed out to sstables.

sstable[0]sstable

write[

memtabcommitlog


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" Compaction helps keep the read latency

low.

sstable[0]sstable

sstable

write[

memtabcommitlog


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Sorted String Tables

mykeyspace-mycf-jb-1-CompressionInfo.db

mykeyspace-mycf-jb-1-Data.dbmykeyspace-mycf-jb-1-Filter.db

mykeyspace-mycf-jb-1-Index.db

mykeyspace-mycf-jb-1-Statistics.db

mykeyspace-mycf-jb-1-Summary.db

mykeyspace-mycf-jb-1-TOC.txt


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Contains all data needed to regenerate compone


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Index of row keys


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Index summary from Index.db file


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Bloom filter over sstable


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Table of contents of all components


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" Case Studies




" Conclusion


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Set up keyspace and column family

create keyspace test

with placement_strategy = 'org.apache.cassandra.locator.Simp

and strategy_options = {replication_factor:1};

create column family test

with comparator = 'AsciiType'and default_validation_class = 'AsciiType'

and key_validation_class = 'AsciiType';


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SStableGen.java

AbstractSSTableSimpleWriter writer = new SSTableSimpleUnsort

directory,

partitioner,

keyspace,

columnFamily,

AsciiType.instance,null,

size_per_sstable_mb

);

// subcomparator for super columns


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SStableGen.java


directory,

partitioner,

keyspace,

columnFamily,


size_per_sstable_mb

);



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SStableGen.java


directory,

partitioner,

keyspace,

columnFamily,


size_per_sstable_mb

);



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ByteBuffer randomBytes = ByteBufferUtil.bytes(randomAscii(1024));

KeyGenerator keyGen = new KeyGenerator();

long dataSize = 0;

writer = new SSTableSimpleUnsortedWriter();

while (dataSize < max_data_bytes) {

writer.newRow(key);

for (int j=0; j


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Examining sstable output

patricia@dev:~/../data$ ls -lh mykeyspace/mycf

total 64

-rw-r--r-- 1 patricia staff 43B Feb 2 15:31 mykeyspace-mycf-jb-1-Com

-rw-r--r-- 1 patricia staff 79K Feb 2 15:31 mykeyspace-mycf-jb-1-Dat

-rw-r--r-- 1 patricia staff 16B Feb 2 15:31 mykeyspace-mycf-jb-1-Fil

-rw-r--r-- 1 patricia staff 36B Feb 2 15:31 mykeyspace-mycf-jb-1-Ind-rw-r--r-- 1 patricia staff 4.3K Feb 2 15:31 mykeyspace-mycf-jb-1-Sta

-rw-r--r-- 1 patricia staff 80B Feb 2 15:31 mykeyspace-mycf-jb-1-Sum

-rw-r--r-- 1 patricia staff 79B Feb 2 15:31 mykeyspace-mycf-jb-1-TOC


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$ bin/sstableloader Keyspace1/ColFam1

patricia@dev:~//cassandra-2.0.4$ bin/sstableloader mykeyspace/mycf-d l

Streaming relevant part of mykeyspace/mycf/mykeyspace-mycf-ic-1-Data.db

progress: [/127.0.0.1 1/1 (100)] [total: 100 - 0MB/s (avg: 0MB/s)]


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patricia@dev:~//cassandra-2.0.4$ bin/sstableloader mykeyspace/mycf-d l




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patricia@dev:~//cassandra-2.0.4$ bin/sstableloader mykeyspace/mycf -d l




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patricia@dev:~//cassandra-2.0.4$ bin/sstableloader mykeyspace/mycf -d l




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" Run command on separate server


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" Throttle command


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" Throttle command

" Parallelise processes


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" Case Studies




" Conclusion

// li t f d b


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// list of orders by user

customerOrders = new SSTableSimpleUnsortedWriter();

// orders by order id

orders = new SSTableSimpleUnsortedWriter();

// assume orders are in date order

for (Order order : oldOrders) {customerOrders.newRow(ByteBufferUtil.bytes(order.customerId));

customerOrders.addColumn(ByteBufferUtil.bytes(order.orderId), ByBufferUtil

timestamp);

orders.newRow(ByteBufferUtil.bytes(order.userId));

orders.addColumn(ByteBufferUtil.bytes(customer_id), ByteBufferUtil.bytes(

timestamp);

orders.addColumn(ByteBufferUtil.bytes(date), ByteBufferUtil.bytes(order.dorders.addColumn(ByteBufferUtil.bytes(total), ByteBufferUtil.bytes(order.

}

customerOrders.close()

orders.close()



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timestamp);



timestamp);


}


orders.close()



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timestamp);



timestamp);


}


orders.close()


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" Case Studies




" Conclusion


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patricia@dev:~//cassandra-2.0.4$ bin/sstableloader mykeyspace/mycf -d \

cass1,cass2,cass3


cass3,cass4,cass5,cass6]

progress: [/cas1 3/3 (100)] [/cas2 0/4 (0)] [/cas3 0/0 (0)] [/cas4 0/0 (

(0)] [/cas6 1/2 (50)] [total: 50 - 0MB/s (avg: 5MB/s)]


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cass1,cass2,cass3



progress: [/cas1 3/3(100)] [/cas2 0/4(0)] [/cas3 0/0 (0)] [/cas4 0/0 (

(0)] [/cas6 1/2(50)] [total: 50 - 0MB/s (avg: 5MB/s)]


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cass1,cass2,cass3



progress: [/cas1 3/3 (100)] [/cas2 0/4 (0)] [/cas3 0/0 (0)] [/cas4 0/0 (

(0)] [/cas6 1/2 (50)] [total: 50- 0MB/s (avg: 5MB/s)]


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patricia@dev:~/.../cassandra-2.0.4$ bin/nodetool compactionstats

pending tasks: 30

Active compaction remaining time : n/a


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" Case Studies




" Conclusion

cqlsh> CREATE KEYSPACE "test"


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CQL: Keep schema consistent

cqlsh> CREATE KEYSPACE test

WITH replication = {'class': 'SimpleStrategy', 'replication_fact

cqlsh> CREATE COLUMNFAMILY "test" (id text PRIMARY KEY ) ;


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CQL3 Considerations

" Uses CompositeType comparator


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Q&A

Patricia Gorla

@patriciagorla

Cassandra Consultant

www.thelastpickle.com

Planet Cassandra 2014
http://www.thelastpickle.com/

bulk loadingdataintocassandra 140307160517 phpapp02

Documents

bulkloading data

bulk loading useful

jb summary

complanet cassandra

dummy data

path writes

path memtable

path compaction