[Cluster-devel] [RFC] Killing ccs for good

[Patrick Caulfield]

Kevin Anderson wrote:
> On Tue, 2007-10-23 at 09:33 +0200, Fabio Massimo Di Nitto wrote:
>> Hi everybody,
>>
>> a few months ago David tickled me with the idea of killing ccs, so I started
>> poking around for fun here and there and I think that I am at a point where
>> we can start looking at the work it has been done so far.
>>
>> What does killing ccs buy us?
>>
>> - remove of another daemon from the stack with everything that comes with it
>>   (less code to handle, less open ports on the network, less stuff to
>> synchronize, etc.)
>> - the option to design a new more useful API.
>> - add your reason here.
>>
>> I created a git branch at git.fugedabout.it sandbox to work on this project:
>>
>> http://git.fugedabout.it/?p=people/fabbione/cluster-noccs.git;a=shortlog;h=noccs
>>
>> You want to remember that this is a test/private branch and it gets rebased once
>> in a while (breaking the classic git pull) and it is on a sandbox == *absolutely
>> no guarantee it will exists in forever*
>>
>> So far we have:
>>
>> - removed completely ccs/ from the tree.
>> - implemented a small libcman API that:
>>   (high level)
>>   - reads random cluster.conf files.
>>   - loads them.
>>   - query them.
>>   (low level)
>>   - handle config conversion from buf to conf and viceversa.
>>   - download/upload the config from/to cman aisexec.
>> - implemented the basic bits in cman/aisexec.
>> - converted all services to use the new API (except rgmanager - see below)
>>
>> The libcman API is not final yet. There might be changes related to the way in
>> which we upload/download config. The API is missing a bunch of ccs_*
>> functionalities that would be seen as regression if missing (even tho i doubt
>> there are that many users out there).
> 
> Some of the "hidden" features of ccs are the ability to create the
> configuration files through command line scripting.  You could at least
> create a cluster and add nodes, although doesn't provide the ability to
> do everything the cluster.conf file.  A command line interface to the
> cluster configuration that covers all aspects of the cluster.conf file
> would be needed before we can remove ccs from the system.  One of the
> things missing from the ccs_tool are adding rgmanager services, am sure
> we are missing other features as well.

Actually the bit of ccs_tool reads and writes the XML file directly and will
need very minimal porting. The only ccs API it uses is to notify ccsd that the
config file has changed.

-- 
Patrick

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