Hi Jon,
The console can take the commands from a script file. Look at the demo
files and how they script the console.
The command looks like: console.bat -p 1090 -f
..\demo\init_derby_raidb1.script
Hope this helps,
Emmanuel
Just one point about the console commands in batch mode... How can
they be issued? Is there anything documented in the manuals? I
couldn't see how to make a windows batch file to execute a backup (for
example...). Is there any console command to be launched scheduled and
admiting parameters?
Best regards,
Jon
Emmanuel Cecchet escribió:
Hi Jon,
The cluster has been configured correctly with this basic settings:
- Two systems (W2003) with 2 postgre 8.3 (one each), 2 HSQLDB 1.8
for the RecoveryLogs (one each) and 2 sequoia controllers (one each)
clustering with JGroups
- Sequoia won't be loaded at boot, since as is a cluster, you don't
now why did the machine boot (failure, maintenance, ...), so it has
no sense. Is this ok?
This is correct. Some have tried to use Sequoia as a service in
Windows (see
http://fossplanet.com/db.sequoia.general/message-188232-sequoia-windows-service/)
but an automatic start is likely to fail without proper diagnostic.
I have two questions regarding the "jump" to production systems:
- For the periodic manteinance of the cluster backups, how could
some console commands (backup a backend, purge RLog1, transfer and
purge RLog2) be put in a batch job (W2003)?
You can probably use a cron replacement for Windows like
http://sourceforge.net/projects/cronw/. Otherwise the Windows Task
Scheduler should do the job (tutorial at
http://www.iopus.com/guides/winscheduler.htm).
- How could the two sequoias be monitored and health checked from
the "network"? Just checking the ports shouldn't be enough...
It depends what kind of health you want to check. You can connect
with the console and check the backends status and check that you
still have enabled backends. Another option is to execute a simple
SELECT statement and make sure that you get a result back.
Hope this helps,
Emmanuel
Jon Urionaguena escribió:
Thanx Emmanuel,
I will keep you informed.. ;-)
Emmanuel Cecchet escribió:
Hi Jon,
Then in the config, I should use a RAIDb-1 config in each
controller specifying just one backend in each (so, not doing
mirroring inside de RAIDb...)? I cannot specify the two same
backends to the two controllers, can I?
You are correct, just 1 backend in each controller. You cannot
share backends between controllers.
Keep us posted with your progress,
Emmanuel
Emmanuel Cecchet escribió:
Jon,
I maybe didn't explain correctly my problematic issues... What
we need is the simplest arch to hold a database system with no
single point of failure, but this database (composed by two
backends in the simplest form) should look as only one to our
apps. So what I think is that we MUST use two controllers, and
I was looking for the correct implementation. As I see, two
controllers could use a singleDB each (I could not start this
config... I will review this case if it's the correct for
us...). Is that ok?
No, SingleDB can only be used with one controller without
replication. If you need replication, you have to use RAIDb-1
with a <Distribution> element in the virtual database
configuration file so that the controllers are synchronized.
Each controller can have a single database backend but the
virtual database will have a total of 2 replicated backends that
will appear as a single database to the client application.
Then the question should be, if these two database backends,
each controlled by a different controller, are indeed
replicated (we can recover one from the other in case of
failure), the database system is fault tolerant with no single
point of failure, and functionally perfom as a single database
to the application... Is this Ok?
Yes, it is. You can look at the distributed RAIDb-1 demo that
ships with Sequoia. You can change the config to have a single
backend per controller and that should be similar to what you
need to build.
I will use another small database in each controller for the
RecoveryLog...
Thanks for your interest in Sequoia,
Emmanuel
Emmanuel Cecchet escribió:
Hi Jon,
I'm new to the list and to sequoia, and so I'm trying to
understand and realize the capabilities of this product.
Welcome and thanks for your interest.
We are trying to find a database architecture as the backend
for our Java apps, with the only requisite of four nine
availability (99,99). The load will always be low. My view is
from the infrastructure point (I know that I should pass this
problem to our dev part, I've done it indeed...), and that's
why I want to build a base platform for deploying different
client solutions in our virtualized datacenter: My needs
should be just two backend databases ("mirrored" ideally)
controlled by two controllers replicating everything.
If you need only 2 database backends, they can also be under
the same controller. The controller becomes a single point of
failure but this can be fine if it is co-located with the
application and the application is not clustered. Now if your
application is also replicated, you can have 2 controllers
with 1 db each.
I was looking at Sequoia+Postgre as the platform, and have
been reading all the documentation it seems to fit well. I
have some doubts:
1) Which should be my simplest configuration? RADIb-1 in each
controller would give me 4 backends... That is supposing that
two controllers cannot control the same two backends, is that
allright?
RAIDb-1 is for mirroring so you are on the right path. You are
right that backends cannot be shared between controllers. But
one controller can have multiple backends. So I am not sure if
you just need to replicate 2 databases on different machines
which will lead to 4 backends (2 for each controller as you
mentioned) or just 1 database in which case 1 backend per
controller is enough.
2) I tried using simpleDB in each controller, but I got
errors saying that no distribution can be done with
simpleDB... Is that allright?
SimpleDB is only meant for 1 database backend only
(cluster-wide). If you replicate a database, you have 2
backends in the cluster and you need RAIDb-1.
3) In the configs I'm proposing, where should the
RecoveryLogs be stored? In the same backends (maybe only in
one of the two?) that compose the DBclusters?
I usually recommend to have the recovery log local to each
controller. Given the small workload that you will have, a
Java database like Derby or Hsqldb can do it on the controller.
Hosting the recovery log on a database backend is error prone
for administration and when you need to service the database
node you will have to stop your controller that will not be
able to work without its recovery log.
I hope this helps,
Emmanuel
--
Emmanuel Cecchet
FTO @ Frog Thinker
Open Source Development & Consulting
--
Web: http://www.frogthinker.org
email: [EMAIL PROTECTED]
Skype: emmanuel_cecchet
_______________________________________________
Sequoia mailing list
[email protected]
https://forge.continuent.org/mailman/listinfo/sequoia
