The ToDo refers to the documentation. The Master holds a lock on a JDBC table, when the Master dies than one of the slave instances looking to obtain that locked table will gain access.
As to a few stories on failover setup, there are a number of approaches... One could setup Master/Slave child instances per host - in this scenario a lock file may be used. One could use a shared lock file between hosts, where the file system supports true locking (ex NFSv4). Alternately you can use JDBC locking mechanism, you just need to ensure you have a highly available DB. As to Dev/Alpha/test environments... that'll depend somewhat more upon your network environment, internal procedures,, and resources such as databases, etc that your applications will have to integrate with. Generally you'd have a separate deployment for each for testing purposes, with the required testing resources for your application (test DBs and other services). Cheers, Jamie On Wed, May 23, 2012 at 10:00 AM, Borut Bolčina <[email protected]> wrote: > Hello, > > I am playing with Karaf (or the other way around), trying to find a solution > how to set up a development and production environments. Yesterday I > installed Cellar features and tried some of the cluster commands and they > seem to work as advertised. > > I would like to devise a plan for deploying bundles and features to a > cluster of Karaf instances on different machines with failover capability. > It is kind of hard as I am still learning OSGi and the whole ecosystem. > > At http://karaf.apache.org/manual/latest-2.2.x/users-guide/failover.html there > is a TODO section for MySql. Does that mean I can not use MySql for jdbc > locking or is there just lack of documentation? > > What does that mean: "If the master loses the lock, a waiting slave process > gains access to the locking table and fully starts its container."? If the > master machine's processor melts, then the slave will come up automatically? > > I would really appreciate some stories on how to set up the fail over > environment and how to deploy to the selected environment (dev, alpha, > production,...) > > Thanks, > borut
