----- Original Message ----- > Hi all, > > Very shortly Mark will be sending some patches for review that > implement the > long-awaited integration of mom with vdsm. I felt it would be easier > to > understand the changes to vdsm if they were explained a bit better. > In support > of this I have created a wiki page on ovirt.org with a diagram: > > http://ovirt.org/wiki/Features/MomIntegration > > To facilitate discussion, here is the text of that page: > > As discussed at the oVirt Workshop and elsewhere, integrating mom > with vdsm will > benefit oVirt by providing a mechanism for dynamic, policy-based > tuning. This > mechanism will pave the way for implementing memory ballooning > policies, can > enhance migration policy, and will replace the existing ksm tuning > thread. > > MOM exists today as an independent library that can be used by python > programs > such as vdsm or in standalone mode (by using the accompanying momd > program. > Mom's operation is very configurable. The management policy is > written in a > Fortran-like language and is replaceable by the end user. > Additionally, plugins > allow you to customize the types of information collected and the > manner in > which it is collected. Similarly, Controller plugins permit a > completely > flexible control API to be created. > > To integrate mom, vdsm will initialize the mom library in a new > thread and start > it. Therefore, mom and vdsm will exist in the same process. Vdsm > will > configure the mom instance to use plugins and a policy that > exclusively target > the vdsm API. All statistics collection will occur via API calls and > any > management actions (including adjustments to KSM and VM balloons) > will be done > through the vdsm api as well. Mom will not use libvirt at all (not > even to > monitor for new VMs on the system). > > Packaging logistics: > ------------------------- > Mom is an independent package that is already in Fedora. Any changes > to mom > that are required to support this integration will be submitted to > the mom > project for inclusion. Vdsm will consume the standard MOM package as > a python > module/library. > > In order to control its mom instance, vdsm will ship a mom > configuration file > and a mom policy file that will set mom's default behavior. At > startup, vdsmd > will import mom and initialize it with the configuration and policy > files. From > that point on, mom will interact with vdsm through the well-defined > API in > API.py. > > New features needed in vdsm: > --------------------------------------- > In order to fully benefit from mom's capabilities, vdsm should > implement the > following extra features/APIs: > > - Collection of more memory statistics via ovirt-guest-agent > including the > current memory balloon value. > - A vmBalloon API to set a new balloon target.
Looks good to me. > > -- > Adam Litke <a...@us.ibm.com> > IBM Linux Technology Center > > _______________________________________________ > vdsm-devel mailing list > firstname.lastname@example.org > https://fedorahosted.org/mailman/listinfo/vdsm-devel > _______________________________________________ vdsm-devel mailing list email@example.com https://fedorahosted.org/mailman/listinfo/vdsm-devel