Added IGNITE-9365 On Thu, Aug 23, 2018 at 3:56 PM Valentin Kulichenko < valentin.kuliche...@gmail.com> wrote:
> Hi David, > > With the Docker image you can actually use additional libraries by > providing URLs to JARs via EXTERNAL_LIBS property. Please refer to this > page: https://apacheignite.readme.io/docs/docker-deployment > > But anyway, I believe that such contribution might be very valuable for > Ignite. Feel free to create a ticket. > > -Val > > On Thu, Aug 23, 2018 at 11:58 AM David Harvey <syssoft...@gmail.com> > wrote: > > > I need an affinityBackupFilter that will prevent backups from running in > > the same AWS availability zone. (A single availability zone has the > > characteristic that some or all of the EC2 instances in that zone can > fail > > together due to a single fault. You have no control over the hosts on > > which the EC2 instance VMs run on in AWS, except by controlling the > > availability zone) . > > > > I could write a few lines of custom code, but then I have to get it > > deployed on all nodes in the cluster, and peer class loading will not > > work. So I cannot use an of the shelf docker image, for example. So > > that code should just be part of Ignite. > > > > I was thinking of adding new class along these lines, where the apply > > function will return true only if none of the node's attributes match > those > > of any of the nodes in the list. This would become part of the code > base, > > but would only be used if configured as the backupAffinityFunction > > > > ClusterNodeNoAttributesMatchBiPredicate implements > > IgniteBiPredicate<ClusterNode, > > > > List<ClusterNode>> { > > > > > > ClusterNodeNoAttributesMatchBiPredicate(String[] attributeNames) > > {....} > > > > For AvailabilityZones, there would be only one attribute examined, but we > > have some potential use cases for distributing backups across two > > sub-groups of an AZ. > > > > Alternately, we could enhance the RendezvousAffinityFunction to allow one > > or more arbitrary attributes to be compared to determine neighbors, > > rather than only org.apache.ignite.macs, and to add a setting that > > controls whether backups should be placed on neighbors if they can't be > > placed anywhere else. > > > > If I have 2 backups and three availability zones (AZ), I want one copy of > > the data in each AZ. If all nodes in one AZ fail, I want to be able to > > decide to try to get to three copies anyway, increasing the per node > > footprint by 50%, or to only run with one backup. This would also > give > > be a convoluted way to change the number of backups of a cache > > dynamically: Start the cache with a large number of backups, but don't > > provide a location where the backup would be allowed to run initially. > > >
