Last week VMware released vFabric Data Director 2.7. Among
the many new features for various database, I wish to give a little more insight into my favorite
ones which are regarding Postgres.
One of the big feature add from a broad perspective is support of Postgres 9.2 based
managed database servers along with replication. Lets look at how it is done in brief.
First vFabric Postgres 9.2 base DBVM needs to be uploaded
into Data Director system resource pool and then converted into template. Note
this template is different from vFabric Postgres 9.2 Virtual appliance and is
available on the same location where Data Director 2.7 download exists. Also this DBVM template is based on the latest PostgreSQL 9.2.4 core.
Next once the template is loaded into the system resource pool it will show
up in Base DBVMs section in System->Manage and Monor-> Templates->
BaseDBVMs
Then you would then right
click on the base DBVM and select “Convert to Base DB Template”. Here you also have a new feature to add more
disks (think Tablespaces in PostgreSQL) to the template. In Data Director 2.7,
disks are added at the template level.
This process take some time and then it should show up in
Base DB Templates. On the Base DB Template section right click on the newly
created template and select “Validate”. This one creates a test database to see
if it is successful or not before it can be rolled out to the Organizations and
Database groups . Once the validation is a success, right click and select “Assign
it to the resource bundle” and select the resource bundle that will have access
to the template or create a new resource bundle to use the template.
Note in the Resource bundle creation steps lies yet another new way to separate out
IO on separate datastores since these may need different IO characteristics
The above image shows how the various types of datastores for your OS, Backup, Data and Logs (Data can be multiple location if you need multiple tablespaces)
Now all the Orgs/Database groups using the resource bundle
will see the new vPostgres 9.2 template.
In a sample demo I created a database called MyDB using few wizard questions.
Now on the DB List we do a right click on the database to
create more replicas
Couple of more quick wizard questions and a slave is ready. Similarly you can create more slaves of the same master. Now actually behind the scenes it does all the plumbing right from creating a new clone virtual machine from the master and setting it up using standard PostgreSQL replication on the newly created VM but from a user point of view it it is all point , click and done.
The database dashboard also has a new portlet to show bit more information about the replication.
To make a slave as a new master and it will give an option to move all the other
slaves to the new master select as follows:
After completion of the failover, the status shown will be similar to:
Where the original slave replica is now redirected to the
new Master. The original master is kept as it is for Port-Mortem or other
activities. This also gives a way to use it as new use cases like separating a
slave for test purpose/DR purpose or separating “mirrors” etc. Best of all it
uses all Standard PostgreSQL replication.
Of course one of the thing that it does not do is re-purpose the original Master as a slave of the new Master. For more details there is a perfect opportunity to find
Heikki Linnakangas from VMware at PGCon in Ottawa this week and ask him the question after his session .. WHY??? :-)