Thank you Alan, that explanation really helped. Would it be useful for me to post my OCF script once its done and tested?
Doug On Wed, 2007-03-21 at 19:13 -0600, Alan Robertson wrote: > Doug Knight wrote: > > Hi Andrew, > > I had just started reviewing both of thes scripts, and reviewed the > > Multistate and clone resource pages on the web site. It looks like > > multistate is how I need to handle it, but a couple of questions first. > > > > 1. I noticed that the write-up says the resource must come up on each of > > the servers in "shadow" mode first, then one gets promoted. Does this > > imply a "start" on both servers, and the OCF start function determining > > which server is active vs shadow (I'm picturing a check in the OCF > > script to determine postgresql standby mode = shadow/crm_master value > > low, and postgresql active mode = active/crm_master value high), then a > > promote to the active server? > > > > 2. I noticed that the drbd OCF script contains a "notify" function, > > where the Stateful OCF script does not. The notify function looks to be > > where the important actions are taken (calling drbd_start_phase_2, > > pre/post, etc). Is the notify function necessary, or is it sufficient in > > my case to handle it through the start|stop|promote|demote functions? > > > > Thanks for your help, > > Doug > > Andrew's out for a while. > > The start function starts you up in slave/secondary mode. All resources > initially start up in "slave" mode. > > A set of servers is chosen to run the resources on (it might be one, > two, the whole set, etc. depending on clone_max and clone_node_max and > the usual constraints). > > They are started on the selected nodes using "start" > > During the start operation, you are given the chance to declare yourself > ready to become master or not by using the crm_master command line tool. > > I believe that your resource can run that command any time they like - > for example at a monitor operation... But, it is mandatory that they > run it when they first start up. > > After this, heartbeat will try and promote as many of these resources as > is consistent with its configured properties, and the crm_master > commands that were run. > > The notify command tells you when your peers come and go. Do you need > to take actions if you know this? > > If so, then you need to implement the notify actions... > > >
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