Alexey Goncharuk created IGNITE-6939:

             Summary: Exclude false owners from the execution plan based on 
query response
                 Key: IGNITE-6939
             Project: Ignite
          Issue Type: Task
      Security Level: Public (Viewable by anyone)
            Reporter: Alexey Goncharuk

This is related to IGNITE-6858, the fix in the ticket can be improved.

The scenario leading to the issue is as follows:
1) Node A has partition 1 as owning
2) Node B has local partition map which has partition 1 on node A as owning
3) Topology change is triggered which would move partition 1 from A to another 
node, topology version is X
4) A transaction is started on node B on topology X
5) Partition is rebalanced and node A moves partition 1 to RENTING and then to 
EVICTED state, node A updates it's local partition map.
6) A new topology change is triggered
7) Node A sends partition map (transitively) to the node B, but since there is 
a pending exchange, node B ignores the updated map and still thinks that A owns 
partition 1 [1]
8) transaction attempts to execute an SQL query against partition 1 on node A 
and retries infinitely

[1] The related code is in 
GridDhtPartitionFullMap, CachePartitionFullCountersMap, Set, 
if (stopping || !lastTopChangeVer.initialized() ||
    // Ignore message not-related to exchange if exchange is in progress.
    (exchangeVer == null && !lastTopChangeVer.equals(readyTopVer)))
    return false;

There are two possibilities to fix this:
1) Make all updates to partition map in a single thread, then we will not need 
update sequences and then we can update local partition map even when there is 
a pending exchange (this is a relatively big, but useful change)
2) Make a change in SQL query execution so that if a node cannot reserve a 
partition, do not map the partition to this node on the same topology version 
anymore (a quick fix)

This message was sent by Atlassian JIRA

Reply via email to