Distributed Systems Maciej opatka Facebook Inbox Search Authors - PowerPoint PPT Presentation

Distributed Systems Maciej Łopatka

 Facebook Inbox Search  Authors Avinash Lakshman (one of the authors of Amazon's Dynamo) and Prashant Malik  Facebook code dump  Community  Transfer to Apache Software Foundation  An Apache top level project

 BigTable data model  An Amazon Dynamo-like infrastructure

 Distributed multidimensional map indexed by a key  Four or five dimensions Key Value Data Timestamp

 Keyspace → Column Family  Column Family → Column Family Row  Column Family Row → Columns  Column → Data value

 Keyspace → Super Column Family  Super Column Family → Super Column Family Row  Super Column Family Row → Columns Row  Column Row → Columns  Column → Data value

 Replication  Log file  Bootstrapping  Partitioning  Consistent Hashing  Periodic Data Compaction  Gossip  Anti-Entropy data sync (uses Merkel tree)  Write and Read Quorum  W + R > N

 RandomPartitioner  OrderPreservingPartitioner

 Terabytes of data  Replaced MySQL  Detecting failures in 15 seconds  ZooKeeper used to locate nodes  Replaced by HBase

 50+TB of data on a 150 node cluster, east and west coast data centers  Term search UserId -> Word -> MessageId Columns  Interaction search UserId -> Recipient UserId -> MessageId Columns Latency Stat Search Inte teractio tions Term Search Min 7.69ms 7.78ms Median 15.69ms 18.27ms Max 26.13ms 44.41ms Tab. Read performance

Workload A — 50 percent reads and 50 percent updates, update heavy: (a) read operations, (b) update operations. Six server-class machines (dual 64-bit quad core 2.5 GHz Intel Xeon CPUs, 8 GB of RAM, 6 disk RAID-10 array and gigabit ethernet)

Workload B — 50 percent reads and 50 percent updates, Read heavy: (a) read operations, (b) update operations. Six server-class machines (dual 64-bit quad core 2.5 GHz Intel Xeon CPUs, 8 GB of RAM, 6 disk RAID-10 array and gigabit ethernet)

 Designed to run on cheap commodity hardware  Handle high write throughput while not sacricing read eciency  Decentralized  Elasticity  Fault-tolerant  Tunable consistency

 http://en.wikipedia.org/wiki/Apache_Cassandra  Cassandra - A Decentralized Structured Storage System, Avinash Lakshman, Prashant Malik, Facebook  http://maxgrinev.com/2010/07/09/a-quick- introduction-to-the-cassandra-data-model/  http://www.facebook.com/note.php?note_id=454991 608919  http://horicky.blogspot.com/2010/10/bigtable- model-with-cassandra-and-hbase.html  http://www.datastax.com/docs/1.0/ddl/index  Benchmarking Cloud Serving Systems with YCSB, Brian F. Cooper, Adam Silberstein, Erwin Tam, Raghu Ramakrishnan, Russell Sears