Partitioning&Sharding
分区是将大数据集拆分成小数据集的方法，拆分会带来两个问题，1 是寻找到分区信息Routing 2 是增减节点时候Rebalance分区
https://en.wikipedia.org/wiki/Shard_(database_architecture)
https://en.wikipedia.org/wiki/Partition_(database)
partition:hazelcast,kafka shard:MongoDB,ES,Solr region:Hbase,TiKV tablet:Bigtable vnode:Cassandra,Riak vBucket(virtual buckets):Couchbase slot:Redis ShardRegion:akka
System
Memcached
Redis:https://redis.io/topics/partitioning https://redis.io/topics/cluster-tutorial
Cassandra https://docs.datastax.com/en/cassandra-oss/3.0/cassandra/architecture/archDataDistributeAbout.html https://cassandra.apache.org/doc/latest/cassandra/architecture/dynamo.html#dataset-partitioning-consistent-hashing
DynamoDB
Google Spanner
Shardingsphere
rethinkdb：https://rethinkdb.com/docs/architecture
HBase：https://hbase.apache.org/book.html#manual_region_splitting_decisions https://hbase.apache.org/book.html#regions.arch
BigTable：
MongoDB：https://docs.mongodb.com/manual/sharding/
voldemort: https://www.project-voldemort.com/voldemort/rebalance.html https://www.project-voldemort.com/voldemort/design.html
Couchbase: https://docs.couchdb.org/en/stable/partitioned-dbs/index.html
MySQL:https://dev.mysql.com/doc/refman/8.0/en/partitioning.html
Riak:
voltdb：https://docs.voltdb.com/UsingVoltDB/IntroHowVoltDBWorks.php
HDFS:https://blog.cloudera.com/partition-management-in-hadoop/
Ketama https://www.metabrew.com/article/libketama-consistent-hashing-algo-memcached-clients
Request Routing
service discovery
https://helix.apache.org/
https://docs.mongodb.com/manual/core/sharded-cluster-config-servers/
https://github.com/couchbase/moxi