topic Re: Activity in MySQL Cluster in Alfresco Archive

Activity in MySQL Cluster

ferrao — Fri, 12 Aug 2011 16:49:48 GMT

Has anybody tried to run activity on a MySQL Cluster?I have tried dumping the schema, needed to change the engine type to ndbcluster and some VARCHARs to TEXT to be able to import it, but i am still getting problems with it.

Re: Activity in MySQL Cluster

ronald_van_kuij — Sat, 13 Aug 2011 07:36:25 GMT

What kind of problems? Rabbits popping out of hats?

Re: Activity in MySQL Cluster

yingying_song — Wed, 21 Dec 2011 07:20:45 GMT

How to resolve this problem ?

Re: Activity in MySQL Cluster

ronald_van_kuij — Wed, 21 Dec 2011 21:23:14 GMT

First would be to add some information that makes sense, helps us get a clearer picture etc… Just 'I have a problem' does not help.

Re: Activity in MySQL Cluster

yingying_song — Thu, 22 Dec 2011 02:35:53 GMT

It seems that mysql cluster doesn't support foreign key.How can we combine Activiti with Mysql cluster?

Re: Activity in MySQL Cluster

maxfieb — Thu, 08 May 2014 10:21:57 GMT

I'd like to see a clear answer to this question not talk of rabbits, even though the original poster seems to have given up long long ago.

mysql-cluster (multi master) is not the same as mysql in a (master-slave) cluster, the stock mysql offers scale out but a read-only copy of the master, via the binary replication log, and can not tolerate loss of the master, or promote the slave to a master (without a lot of manual pain). The slave cannot tolerate even a short outage to master (with a high database write rate), the slave will stop receiving changes and become a static snapshot in time, and requires manual re-syncing of the correct position of the change log on the master. So it is not robust at all, except for having a backup, maybe.

mysql-cluster is a different product, it offers redundancy, not just scale-out, if a master dies another server can take on the role, and clients can be failed over (via a content switch, or software appliance, to another server. But as the writer above said, it used the clustered database storage engine ndbcluster (whereas on mysql you have InnoDB / MyISAM the storage engines are compatible and only slightly different) which has some significant syntactical differences.

It would be a relatively simple answer, if the mysql supported was the standard mysql (master-slave) or clustered mysql-cluster (master-master).. if this were true there would need to be a specific schema written for it, as it is different to regular mysql. If there is only a single mysql schema, then I'm assuming mysql-cluster not tested, but it might work with a little (maybe a lot?) of tweaking.