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MySQL的innodb和cluster的NDB引擎都支持事务，在有共同的特性外，也有不同之处：
以mysql cluster NDB 7.3和MySQL 5.6之InnoDB为例：
ndb7.3基于mysql5.6，包括支持innodb1.1，因此可以在cluster里使用innodb表，但这些表不是集群的。
MySQL Cluster NDB存储引擎用分布式, shared-nothing的架构实现，这使其和innodb有不少不同之处。比如事务、外键、表限制等，具体见下表：
Theseare shown in the following table:
Feature |
|
MySQLCluster |
|---|---|---|
MySQLServer Version |
5.6 |
5.6 |
|
|
|
MySQLCluster Version |
N/A |
|
StorageLimits |
64TB |
3TB (Practicalupper limit based on 48 data nodes with 64GB RAM each; can beincreased with disk-based data and BLOBs) |
ForeignKeys |
Yes |
Priorto MySQL Cluster NDB 7.3: No. (Ignored, as with Availablein MySQL Cluster NDB 7.3. |
Transactions |
Allstandard types |
|
MVCC |
Yes |
No |
DataCompression |
Yes |
No (MySQLCluster checkpoint and backup files can be compressed) |
LargeRow Support (> 14K) |
Supportedfor (Usingthese types to store very large amounts of data can lower MySQLCluster performance) |
|
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) |
Scaleoutfor Write Operations |
Requiresapplication-level partitioning (sharding) |
Yes(Automatic partitioning in MySQL Cluster is transparent toapplications) |
HighAvailability (HA) |
Requiresadditional software |
Yes(Designed for 99.999% uptime) |
NodeFailure Recovery and Failover |
Requiresadditional software |
Automatic (Keyelement in MySQL Cluster architecture) |
Timefor Node Failure Recovery |
30seconds or longer |
Typically< 1 second |
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. |
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 |
这两种存储引擎适合的应用场景
Preferredapplication requirements for |
Preferredapplication requirements for |
|---|---|
|
|
2
如何选择memory存储引擎或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存储引擎和MySQL Cluster的更多细节对比参见白皮书《Scaling Web Services with MySQL Cluster: An Alternative to the MySQL Memory Storage Engine》
Table 15.4 MEMORYStorage Engine Features
Storagelimits |
RAM |
Transactions |
No |
Lockinggranularity |
Table |
MVCC |
No |
Geospatialdata type support |
No |
Geospatialindexing support |
No |
B-treeindexes |
Yes |
T-treeindexes |
No |
Hashindexes |
Yes |
Full-textsearch indexes |
No |
Clusteredindexes |
No |
Datacaches |
N/A |
Indexcaches |
N/A |
Compresseddata |
No |
Encrypteddata[a] |
Yes |
Clusterdatabase support |
No |
Replicationsupport[b] |
Yes |
Foreignkey support |
No |
Backup/ point-in-time recovery[c] |
Yes |
Querycache support |
Yes |
Updatestatistics for data dictionary |
Yes |
|
[a]Implemented in the server (via encryption functions), ratherthan in the storage engine. [b]Implemented in the server, rather than in the storage engine. [c]Implemented in the server, rather than in the storage engine. |
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3
myisam, memory, ndb, archive, innodb存储引擎功能汇总：
Table 15.1 StorageEngines Feature Summary
Feature |
MyISAM |
Memory |
InnoDB |
Archive |
NDB |
|---|---|---|---|---|---|
Storagelimits |
256TB |
RAM |
64TB |
None |
384EB |
Transactions |
No |
No |
Yes |
No |
Yes |
Lockinggranularity |
Table |
Table |
Row |
Table |
Row |
MVCC |
No |
No |
Yes |
No |
No |
Geospatialdata type support |
Yes |
No |
Yes |
Yes |
Yes |
Geospatialindexing support |
Yes |
No |
Yes[a] |
No |
No |
B-treeindexes |
Yes |
Yes |
Yes |
No |
No |
T-treeindexes |
No |
No |
No |
No |
Yes |
Hashindexes |
No |
Yes |
No[b] |
No |
Yes |
Full-textsearch indexes |
Yes |
No |
Yes[c] |
No |
No |
Clusteredindexes |
No |
No |
Yes |
No |
No |
Datacaches |
No |
N/A |
Yes |
No |
Yes |
Indexcaches |
Yes |
N/A |
Yes |
No |
Yes |
Compresseddata |
Yes[d] |
No |
Yes[e] |
Yes |
No |
Encrypteddata[f] |
Yes |
Yes |
Yes |
Yes |
Yes |
Clusterdatabase support |
No |
No |
No |
No |
Yes |
Replicationsupport[g] |
Yes |
Yes |
Yes |
Yes |
Yes |
Foreignkey support |
No |
No |
Yes |
No |
No |
Backup/ point-in-time recovery[h] |
Yes |
Yes |
Yes |
Yes |
Yes |
Querycache support |
Yes |
Yes |
Yes |
Yes |
Yes |
Updatestatistics for data dictionary |
Yes |
Yes |
Yes |
Yes |
Yes |
|
[a]InnoDB support for geospatial indexing is available in MySQL5.7.5 and higher. [b]InnoDB utilizes hash indexes internally for its AdaptiveHash Index feature. [c]InnoDB support for FULLTEXT indexes is available in MySQL5.6.4 and higher. [d]Compressed MyISAM tables are supported only when using thecompressed row format. Tables using the compressed row formatwith MyISAM are read only. [e]Compressed InnoDB tables require the InnoDB Barracuda fileformat. [f]Implemented in the server (via encryption functions), ratherthan in the storage engine. [g]Implemented in the server, rather than in the storageengine. [h]Implemented in the server, rather than in the storageengine. |
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