There are a bunch of "rebalance" cache metrics ( https://ignite.apache.org/docs/latest/monitoring-metrics/new-metrics#caches). Do they not do what you need?
I don't know enough about the internals to guide you on the ordering, but I would say that it's not a good idea to subscribe to CACHE_ENTRY_* events. There could be millions of them. AFAIK, you can't configure a cluster singleton service as you suggest. The idea is that the cluster manages it for you. You can limit which nodes it runs on using cluster groups. It's more common to use node singletons so that you service scales. On Wed, 4 Dec 2024 at 11:18, <jrov...@identy.io> wrote: > Hi. > > > > We are currently working on a feature to track the rebalancing of our > Ignite cluster listening all events: when it starts and end, how many > partitions are sent, etc. > > > > We implemented a singleton Ignite Service and deploy it on the cluster. > > > > When the service starts it listens the following remote events: > > EVT_NODE_JOINED > > EVT_NODE_LEFT > > EVT_NODE_FAILED > > EVT_NODE_SEGMENTED > > EVT_CACHE_REBALANCE_STARTED > > EVT_CACHE_REBALANCE_STOPPED > > EVT_CACHE_REBALANCE_PART_SUPPLIED > > EVT_CACHE_REBALANCE_PART_LOADED > > EVT_CACHE_REBALANCE_PART_UNLOADED > > EVT_CACHE_REBALANCE_PART_DATA_LOST > > EVT_CACHE_REBALANCE_PART_MISSED > > > > Some questions about our approach: > > > > 1. Is the following sequence of events correct? > > > - Baseline: A,B > - setBaselineTopology: A, B, C, D > > > > - C and D send event EVT_CACHE_REBALANCE_STARTED > > > > - A and B send multiple EVT_CACHE_REBALANCE_PART_SUPPLIED with the > partitions to rebalance > > > > - C and D receive data from A and B > - C and D send multiple CACHE_ENTRY_CREATED, CACHE_ENTRY_DESTROYED, > CACHE_REBALANCE_OBJECT_LOADED to create new entries > - C and D send multiple CACHE_REBALANCE_PART_LOADED when the data is > loaded into the new nodes > > > > - C and D send event EVT_CACHE_REBALANCE_STOPPED > > > > - A and B send multiple CACHE_ENTRY_CREATED, CACHE_ENTRY_DESTROYED, > CACHE_REBALANCE_OBJECT_UNLOADED to remove old entries > - A and B send multiple EVT_CACHE_REBALANCE_PART_UNLOADED when the > partitions are removed > > > > > > 2. As you can see, I receive some CACHE_ENTRY_DESTROYED when C and D > are receiving the data. Why are they destroying entries? Also, something > similar happens when A and B are removing partitions, I receive some > CACHE_ENTRY_CREATED. > > > > 3. Sometimes I did not receive an EVT_CACHE_REBALANCE_STARTED from a > node that is supposed to start a rebalancing, how is this possible? > > > > 4. About the use of services, when the node that contains a service is > removed from the cluster, it is translated to another node. Is there a way > to do it manually? A mean, for example I know that the node is processing a > lot of data, and I want to transfer this service to a different node, is it > possible to do it? > > > > 5. We want to know if a rebalancing is in course, is there a way to > ask the cluster about this? We currently listen the events and maintain a > variable with this state, but if the service dies… the variable is lost. > > > > Thank you. > > > > > > >
