Open topic with navigation
NuoDB no longer supports managed databases and template support as of NuoDB Release 3.0.
Safe commit is the default for managed databases and stock templates from NuoDB version 3.0. For existing managed databases, you must shut down and restart using the new setting if you wish to deploy the Safe commit mode.
Customers who use the Managed approach require an easy way to convert a Managed database to Unmanaged. The Mgr CLI program
nuodbmgr in previous releases disallows you to perform
capture file on a managed database. However, this restriction has been removed in version 3.0 so that users can easily capture a Managed database, delete its description, and then restart as an Unmanaged database.
1. Capture Database
nuodbmgr --broker localhost --password bird \ --command "capture database prod dbFile /tmp/prod.txt"
2. Shutdown Database
nuodbmgr --broker localhost --password bird \ --command "shutdown database prod"
3. Delete Database
nuodbmgr --broker localhost--password bird \ --command "delete database prod"
4. Restart Database
nuodbmgr --broker localhost --password bird \ --command "restart database prod dbFile /tmp/prod.txt"
To make managing the scalability, reliability, and redundancy goals for your databases easier, NuoDB introduced the concept of a database template. A template specifies a Service Level Agreement (SLA)A contract between two or more parties that defines services to be delivered. NuoDB templates are an example of an SLA. for any databases to which it is applied. NuoDB's management tier enforces the SLA at all times and automatically restarts TEs or SMs on hosts as necessary to ensure that the template's specification is maintained. For example, suppose a host on which TEs or SMs are running becomes unavailable. NuoDB starts replacement TEs or SMs on other hosts in the domain to enforce the SLA. NuoDB includes the following templates:
A template is applied to a database when the database is created. A database created with a template is referred to as a managed database. The template specifies at a logical level how resources in the domain should be used to create and manage an appropriate configuration of TEs and SMs across the domain's hosts and regions as required to maintain the SLA required for a given database. For example, NuoDB ensures that databases created with the Minimally Redundant template are on at least two hosts in the domain with each host running a transaction engine and a storage manager. If more hosts are available, NuoDB distributes the four processes (2 TEs and 2 SMs) on up to four hosts.
If scalability, availability, or redundancy requirements change after you create a database, you can apply a different template at any time. NuoDB automatically adjusts the configuration of TEs and SMs in the domain according to the new template.
If you are running a single host database, then you must change it to at least a minimally redundant database but it is preferable to change it to a multi-host database. To make these changes, you might need to add one or two hosts to your domain (see Creating the Domain and Adding Hosts). An example of updating a single host database to a minimally redundant database is described in Upgrading Your First Database to Be Minimally Redundant. When running a minimally redundant database, which has two SMs, when you use one SM to obtain a copy of current state, then you must shut down that SM to obtain the copy. Your database does not have redundancy during this time. This is why the recommendation is to change to a multi-host database and provision at least three hosts.