mysql的innodb和cluster的NDB引擎都支持事務，在有共同的特性外，也有不同之處：
以mysql cluster NDB 7.3和MySQL 5.6之InnoDB為例：
ndb7.3基於mysql5.6，包括支持innodb1.1，因此可以在cluster裡使用innodb表，但這些表不是集群的。
MySQL Cluster NDB存儲引擎用分佈式, shared-nothing的架構實現，這使其和innodb有不少不同之處。比如事務、外鍵、表限制等，具體見下表：
Theseare shown in the following table:
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Feature |
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MySQLCluster |
|---|---|---|
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MySQLServer Version |
5.6 |
5.6 |
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MySQLCluster Version |
N/A |
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StorageLimits |
64TB |
3TB (Practicalupper limit based on 48 data nodes with 64GB RAM each; can beincreased with disk-based data and BLOBs) |
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ForeignKeys |
Yes |
Priorto MySQL Cluster NDB 7.3: No. (Ignored, as with
|
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Transactions |
Allstandard types |
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MVCC |
Yes |
No |
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DataCompression |
Yes |
No (MySQLCluster checkpoint and backup files can be compressed) |
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LargeRow Support (> 14K) |
Supportedfor |
Supportedfor
|
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ReplicationSupport |
Asynchronousand semisynchronous replication using MySQL Replication |
Automaticsynchronous replication within a MySQL Cluster. Asynchronousreplication between MySQL Clusters, using MySQL Replication |
|
Scaleoutfor Read Operations |
Yes(MySQL Replication) |
Yes(Automatic partitioning in MySQL Cluster; MySQL Replication) |
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Scaleoutfor Write Operations |
Requiresapplication-level partitioning (sharding) |
Yes(Automatic partitioning in MySQL Cluster is transparent toapplications) |
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HighAvailability (HA) |
Requiresadditional software |
Yes(Designed for 99.999% uptime) |
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NodeFailure Recovery and Failover |
Requiresadditional software |
Automatic (Keyelement in MySQL Cluster architecture) |
|
Timefor Node Failure Recovery |
30seconds or longer |
Typically< 1 second |
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Real-TimePerformance |
No |
Yes |
|
In-MemoryTables |
No |
Yes (Somedata can optionally be stored on disk; both in-memory and diskdata storage are durable) |
|
NoSQLAccess to Storage Engine |
Nativememcached interface in development (see the MySQL Dev ZonearticleMySQLCluster 7.2 (DMR2): NoSQL, Key/Value, Memcached) |
Yes MultipleAPIs, including Memcached, Node.js/JavaScript, Java, JPA, C++,and HTTP/REST |
|
Concurrentand Parallel Writes |
Notsupported |
Upto 48 writers, optimized for concurrent writes |
|
ConflictDetection and Resolution (Multiple Replication Masters) |
No |
Yes |
|
HashIndexes |
No |
Yes |
|
OnlineAddition of Nodes |
Read-onlyreplicas using MySQL Replication |
Yes(all node types) |
|
OnlineUpgrades |
No |
Yes |
|
OnlineSchema Modifications |
Yes,as part of MySQL 5.6. |
Yes. |
數據驅動型應用負載於innodb和NDB存儲引擎之主要不同：
|
Workload |
|
MySQLCluster ( |
|---|---|---|
|
High-VolumeOLTP Applications |
Yes |
Yes |
|
DSSApplications (data marts, analytics) |
Yes |
Limited(Join operations across OLTP datasets not exceeding 3TB in size) |
|
CustomApplications |
Yes |
Yes |
|
PackagedApplications |
Yes |
Limited(should be mostly primary key access). MySQLCluster NDB 7.3 supports foreign keys. |
|
In-NetworkTelecoms Applications (HLR, HSS, SDP) |
No |
Yes |
|
SessionManagement and Caching |
Yes |
Yes |
|
E-CommerceApplications |
Yes |
Yes |
|
UserProfile Management, AAA Protocol |
Yes |
Yes |
這兩種存儲引擎適合的應用場景
|
Preferredapplication requirements for |
Preferredapplication requirements for |
|---|---|
|
Foreignkeys Note MySQLCluster NDB 7.3 supports foreign keys. Fulltable scans Verylarge databases, rows, or transactions Transactionsother than |
Writescaling 99.999%uptime Onlineaddition of nodes and online schema operations MultipleSQL and NoSQL APIs (seeMySQLCluster APIs: Overview and Concepts) Real-timeperformance Limiteduse of
|
2
如何選擇memory存儲引擎或mysql cluster：
When to Use MEMORY or MySQL Cluster.
Developers looking to deploy applications that use the MEMORY storage engine for important, highly available, or frequently updated data should consider whether MySQL Cluster is a better choice. A typical use case for the MEMORY engine involves these
characteristics:
? Operations involving transient, non-critical data such as session management or caching. When the MySQL server halts or restarts, the data in MEMORY tables is lost.
? In-memory storage for fast access and low latency. Data volume can fit entirely in memory without causing the operating system to swap out virtual memory pages.
? A read-only or read-mostly data access pattern (limited updates).
MySQL Cluster offers the same features as the MEMORY engine with higher performance levels, and provides additional features not available with MEMORY:
? Row-level locking and multiple-thread operation for low contention between clients.
? Scalability even with statement mixes that include writes.
? Optional disk-backed operation for data durability.
? Shared-nothing architecture and multiple-host operation with no single point of failure, enabling 99.999% availability.
? Automatic data distribution across nodes; application developers need not craft custom sharding or partitioning solutions.
? Support for variable-length data types (including BLOB and TEXT) not supported by MEMORY.
MEMORY存儲引擎和MySQL Cluster的更多細節對比參見白皮書《Scaling Web Services with MySQL Cluster: An Alternative to the MySQL Memory Storage Engine》
Table 15.4 MEMORYStorage Engine Features
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myisam, memory, ndb, archive, innodb存儲引擎功能匯總：
Table 15.1 StorageEngines Feature Summary
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要選mysql cluster要根據ndb存儲引擎的特征和應用場景做詳細測試