Hi Alan, I am sorry for the typo in your name, it was done unintentionally.
Thanks, S. чт, 4 февр. 2021 г. в 19:10, Вячеслав Коптилин <slava.kopti...@gmail.com>: > Hello Allan, > > > Does data rebalancing occur when a node leaves or joins, or only when > you manually change the baseline topology (assuming automatic baseline > adjustment is disabled)? Again, this is on a cluster with persistence > enabled. > Yes, this can happen when a node joins the cluster, for instance. > Let's consider the following scenario: you shut down a node that is a part > of the current baseline topology, and so, this node cannot apply updates. > After a while, this node was restarted and returned to the cluster. In > this case, rebalancing can be triggered in order to transfer that updates. > > > 2. Sometimes I look at the partition counts of a cache across all the > nodes using > Arrays.stream(ignite.affinity(cacheName).primaryPartitions(severNode) and I > see 0 partition > > After a while it returns to a balanced state. What's going on here? > Well, when a partition needs to be rebalanced from one node (supplier) to > another one (demander) we create a partition on the demander in a MOVING > state (this means a backup that applies updates but cannot be used for > reads). > When this partition fully rebalanced it is switched to OWNING state and > the next PME (Late Affinity Assignment) may mark this partition as a > primary. > > > 3. Is there a way to manually invoke the partition map exchange process? > I don't think so. > > > 4. Sometimes I see 'partition lost' errors. If i am using persistence > and all the baseline nodes are online and connected, is it safe to assume > no data has been lost and just call cache.resetLostPartitions(myCaches)? > If I am not mistaken, the answer is yes. Please take a look at > https://ignite.apache.org/docs/latest/configuring-caches/partition-loss-policy#recovering-from-a-partition-loss > > Thanks, > S. > > пт, 29 янв. 2021 г. в 15:56, Alan Ward <arw...@gmail.com>: > >> I'm using Ignite 2.9.1, a 5 node cluster with persistence enabled, >> partitioned caches with 1 backup. >> >> I'm a bit confused about the difference between data rebalancing and >> partition map exchange in this context. >> >> 1. Does data rebalancing occur when a node leaves or joins, or only when >> you manually change the baseline topology (assuming automatic baseline >> adjustment is disabled)? Again, this is on a cluster with persistence >> enabled. >> >> 2. Sometimes I look at the partition counts of a cache across all the >> nodes using >> Arrays.stream(ignite.affinity(cacheName).primaryPartitions(severNode) and I >> see 0 partitions on one or even two nodes for some of the caches. After a >> while it returns to a balanced state. What's going on here? Is this data >> rebalancing at work, or is this the result of the partition map exchange >> process determining that one node is/was down and thus switching to use the >> backup partitions? >> >> 3. Is there a way to manually invoke the partition map exchange process? >> I figured it would happen on cluster restart, but even after restarting the >> cluster and seeing all baseline nodes connect I still observe the partition >> imbalance. It often takes hours for this to resolve. >> >> 4. Sometimes I see 'partition lost' errors. If i am using persistence and >> all the baseline nodes are online and connected, is it safe to assume no >> data has been lost and just call cache.resetLostPartitions(myCaches)? Is >> there a way calling that method would lead to data loss with persistence >> enabled? >> >> thanks for your help! >> >
