使用 MEMORY 引擎存储的表是否可以从集群崩溃中恢复？答案

【问题标题】：Are the tables stored with MEMORY engine recoverable from cluster crash?使用 MEMORY 引擎存储的表是否可以从集群崩溃中恢复？
【发布时间】：2014-05-14 06:23:16
【问题描述】：

我已经设置了 MySQL NDB Cluster 7.3.5 并且集群工作正常。

有 4 个节点的集群：

NodeA : SQLNode1, DataNode1

NodeB : SQLNode2, DataNode2

NodeC : Mgmt Node1

NodeD : Mgmt Node2

为了测试服务器重启场景，我重启了 VMWare ESXi 并重启了所有虚拟机。

但数据节点随后无法启动。

分别为服务器添加日志：

/home/mysql/mysqlcluster_data/1/ndb_1_out.log（数据节点1）

error: [ code: 708 line: 38848236 node: 1 count: 1 status: 32687 key: 445914048 name: 'hhmefep/def/fgvmev0000000000-elog-1398414831' ] 
2014-05-13 13:16:40 [ndbd] INFO -- Failed to recreate object 505 during restart, error 708. 
2014-05-13 13:16:40 [ndbd] INFO -- DBDICT (Line: 4688) 0x00000000 
2014-05-13 13:16:40 [ndbd] INFO -- Error handler restarting system 
2014-05-13 13:16:40 [ndbd] INFO -- Error handler shutdown completed - exiting 
2014-05-13 13:16:40 [ndbd] ALERT -- Angel detected too many startup failures(3), not restarting again 
2014-05-13 13:16:40 [ndbd] ALERT -- Node 1: Forced node shutdown completed. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'.

似乎节点无法恢复此表： hhmefep.fgvmev0000000000-elog-1398414831

/home/mysql/mysqlcluster_data/2/ndb_2_out.log（数据节点2）

2014-05-13 13:05:48 [ndbd] INFO -- Start phase 1 completed 
2014-05-13 13:05:48 [ndbd] INFO -- Start phase 2 completed 
2014-05-13 13:05:48 [ndbd] INFO -- Start phase 3 completed 
2014-05-13 13:05:51 [ndbd] INFO -- Node 1 disconnected 
2014-05-13 13:05:51 [ndbd] INFO -- QMGR (Line: 3308) 0x00000000 
2014-05-13 13:05:51 [ndbd] INFO -- Error handler restarting system 
2014-05-13 13:05:51 [ndbd] INFO -- Error handler shutdown completed - exiting 
2014-05-13 13:05:51 [ndbd] ALERT -- Angel detected too many startup failures(3), not restarting again 
2014-05-13 13:05:51 [ndbd] ALERT -- Node 2: Forced node shutdown completed. Occured during startphase 4. Caused by error 2308: 'Another node failed during system restart, please investigate error(s) on other node(s)(Restart error). Temporary error, restart node'.

似乎数据节点 2 正在尝试与数据节点 1 同步，但已被管理节点强制关闭。

（管理节点）

ndb_mgm> Node 1: Forced node shutdown completed, restarting. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'. 
Node 1: Forced node shutdown completed, restarting. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'. 
Node 1: Forced node shutdown completed. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'. 
Node 2: Forced node shutdown completed, restarting. Occured during startphase 4. Caused by error 2308: 'Another node failed during system restart, please investigate error(s) on other node(s)(Restart error). Temporary error, restart node'. 
Node 2: Forced node shutdown completed, restarting. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'. 

ndb_mgm> Node 2: Forced node shutdown completed. Occured during startphase 4. Caused by error 2355: 'Failure to restore schema(Resource configuration error). Permanent error, external action needed'.

请帮助我，因为这非常令人沮丧。

【问题讨论】：

标签： mysql mysql-cluster

【解决方案1】：

根据MySQL memory engine page:

MEMORY 存储引擎（以前称为 HEAP）创建具有存储在内存中的内容的专用表。 因为数据容易受到崩溃、硬件问题或电源的影响中断，仅将这些表用作临时工作区或只读缓存用于从其他表中提取的数据。

【讨论】：