Spec-Zone .ru
спецификации, руководства, описания, API
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Spec-Zone .ru
спецификации, руководства, описания, API
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The MySQL Cluster NDB storage engine is implemented using a distributed, shared-nothing
architecture, which causes it to behave differently from InnoDB in a number of ways. For those unaccustomed to working with NDB,
unexpected behaviors can arise due to its distributed nature with regard to transactions, foreign keys, table
limits, and other characteristics. These are shown in the following table:
Feature |
|
MySQL Cluster |
|---|---|---|
MySQL Server Version |
5.6 |
5.6 |
|
|
|
MySQL Cluster Version |
N/A |
|
Storage Limits |
64TB |
3TB (Practical upper limit based on 48 data nodes with 64GB RAM each; can be increased with disk-based data and BLOBs) |
Foreign Keys |
Yes |
Yes (Developer preview release) |
Transactions |
All standard types |
|
MVCC |
Yes |
No |
Data Compression |
Yes |
No (MySQL Cluster checkpoint and backup files can be compressed) |
Large Row Support (> 14K) |
Supported for (Using these types to store very large amounts of data can lower MySQL Cluster performance) |
|
Replication Support |
Asynchronous and semi-synchronous replication using MySQL Replication |
Automatic synchronous replication within a MySQL Cluster. Asynchronous replication between MySQL Clusters, using MySQL Replication |
Scaleout for Read Operations |
Yes (MySQL Replication) |
Yes (Automatic partitioning in MySQL Cluster; MySQL Replication) |
Scaleout for Write Operations |
Requires application-level partitioning (sharding) |
Yes (Automatic partitioning in MySQL Cluster is transparent to applications) |
High Availability (HA) |
Requires additional software |
Yes (Designed for 99.999% uptime) |
Node Failure Recovery and Failover |
Requires additional software |
Automatic (Key element in MySQL Cluster architecture) |
Time for Node Failure Recovery |
30 seconds or longer |
Typically < 1 second |
Real-Time Performance |
No |
Yes |
In-Memory Tables |
No |
Yes (Some data can optionally be stored on disk; both in-memory and disk data storage are durable) |
NoSQL Access to Storage Engine |
Native memcached interface in development (see the MySQL Dev Zone article ) |
Yes Multiple APIs, including Memcached, Node.js/JavaScript, Java, JPA, C++, and HTTP/REST |
Concurrent and Parallel Writes |
Not supported |
Up to 48 writers, optimized for concurrent writes |
Conflict Detection and Resolution (Multiple Replication Masters) |
No |
Yes |
Hash Indexes |
No |
Yes |
Online Addition of Nodes |
Read-only replicas using MySQL Replication |
Yes (all node types) |
Online Upgrades |
No |
Yes |
Online Schema Modifications |
Yes |
Yes |